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Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances
(2008)
Background: Water-filtered infrared-A (wIRA) irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone.
Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised controlled study in humans.
Methods: The penetration profiles of the hydrophilic dye fluorescein and the lipophilic dye curcumin in separate standard water-in-oil emulsions were determined on the inner forearm of test persons by tape stripping in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Transepidermal water loss, hydration of the epidermis, and surface temperature were determined. Three different procedures (modes A, B, C) were used in a randomised order on three separate days of investigation in each of 12 test persons. In mode A, the two dyes were applied on different skin areas without water-filtered infrared-A (wIRA) irradiation. In mode B, the skin surface was irradiated with wIRA over 30 min before application of the two dyes (Hydrosun® radiator type 501, 10 mm water cuvette, orange filter OG590, water-filtered spectrum: 590–1400 nm with dominant amount of wIRA). In mode C, the two dyes were applied and immediately afterwards the skin was irradiated with wIRA over 30 min. In all modes, tape stripping started 30 min after application of the formulations. Main variable of interest was the ratio of the amount of the dye in the deeper (second) 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum.
Results: The penetration profiles of the hydrophilic fluorescein showed in case of pretreatment or treatment with wIRA (modes B and C) an increased penetration depth compared to the non-irradiated skin (mode A): The ratio of the amount of the dye in the deeper (second) 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum showed medians and interquartile ranges for mode A of 0.017 (0.007/0.050), for mode B of 0.084 (0.021/0.106), for mode C of 0.104 (0.069/0.192) (difference between modes: p=0.0112, significant; comparison mode A with mode C: p<0.01, significant). In contrast to fluorescein, the lipophilic curcumin showed no differences in the penetration kinetics, in reference to whether the skin was irradiated with wIRA or not. These effects were confirmed by laser scanning microscopy. Water-filtered infrared-A irradiation increased the hydration of the stratum corneum: transepidermal water loss rose from approximately 8.8 g m-2 h-1 before wIRA irradiation to 14.2 g m-2 h-1 after wIRA irradiation and skin hydration rose from 67 to 87 relative units. Skin surface temperature increased from 32.8°C before wIRA to 36.4°C after wIRA irradiation.
Discussion: The better penetration of the hydrophilic dye fluorescein after or during skin irradiation (modes B and C) can be explained by increased hydration of the stratum corneum by irradiation with wIRA.
Conclusions: As most topically applied substances for the treatment of patients are mainly hydrophilic, wIRA can be used to improve the penetration of substances before or after application of substances – in the first case even of thermolabile substances – with a broad clinical relevance as a contact free alternative to an occlusive dressing.
Fit to play : posture and seating position analysis with professional musicians - a study protocol
(2017)
Background: Musical performance-associated musculoskeletal disorders (MSD) are a common health problem among professional musicians. Considering the manifold consequences arising for the musicians, they can be seen as a threat for their professional activity. String players are the most affected group of musicians in this matter. Faults in upper body posture while playing the instrument, causing un-ergonomic static strain on the back and unergonomic limp-movements, are a main reason for musculoskeletal disorders and pain syndromes.
Methods: A total of 66 professional musicians, divided into three groups, are measured.
The division is performed by average duration of performance, intensity of daily exercise and professional experience. Video raster stereography, a three-dimensional analysis of the body posture, is used to analyse the instrument-specific posture. Furthermore the pressure distribution during seating is analysed. Measurements are performed because the musician is sitting on varying music chairs differing in structure and/or construction of the seating surface. The measurements take place in habitual seating position as well as during playing the instrument.
Results: To analyse the influence of different chairs, ANOVA for repeated measurements or Friedman-test is used, depending on normality assumptions. Comparison of posture between amateur musicians, students, and professional orchestral musicians is carried out the non-parametric Jonckheere-Terpstra-test.
Conclusions: Our method attempts to give the musicians indications for the right music chair choice by analyzing the chair concepts, so that thereby preemptively MSD can be reduced or prevented.
Introduction: Musicians often perform in forced postures over a long period of time, which in the worst case may lead to playing-related musculoskeletal disorders. In this context, the ergonomics of the musician's chair (construction and surface quality) can be an influencing factor, with impact on the seating position of the upper body and the pressure distribution of the bottom. Therefore, the relationship between different musician chairs and musicians of different playing levels (professional, amateur or student) was analyzed in order to gain useful insights whether playing experience, playing level, playing style (symmetrical or asymmetrical) or gender have an impact.
Method: The total dataset of 47 musicians (3 playing levels: professional, amateur, student) were analysed on six musician chairs with different ergonomic layout. Sitting on each chair without instrument (condition 1) and with instrument (condition 2), the upper body posture (videorasterstereography) and the seat pressure (load distribution) were recorded.as Also, a subjective assessment concerning constitutional data, sitting behaviour, prevailing pain in the musculoskeletal system, sport activity and chair comfort rating, was completed using a questionnaire.
Results: There were significant differences shown in 6 of 17 variables, where all between and within factors were accounted for with a MANOVA. Two measurements of the upper body posture (scapular distance and scapular height) differentiated between playing level. Four of the pressure measurements (pressure under the sit bone and the thigh for the left and the right side) differentiated between chairs and the two conditions (with and without instrument). Chairs with soft cushioning had a mean pressure reduction of about 30%. The pressure was increased by about 10% while playing an instrument. Subjective rating was correlated to age for some of the chairs.
Discussion: Differences between chairs are mainly associated with the pressure distribution under the sitting surface. Playing with an instrument puts an additional force onto the surface of the chair that is more than the weight of the instrument. No relationship between pressure data and upper body posture data could be found. Therefore, it can be speculated that the intersubject variability is larger than systematic differences introduced by the chair or instrument.
Background: Effects of playing high stringed bow instruments on the upper body posture have not been analysed so far. The instrument-specific seating position when playing in an orchestra is compared to the habitual seating position.
Methods: Three dimensional back scans were performed in 13 professional violinists and viola players of a radio orchestra (8 f / 5 m). Trunk position in their habitual seating position and in the instrument- specific seating position imitating playing was compared. Statistical differences were calculated using Wilcoxon Matched Pairs Test with Bonferroni Holm correction.
Results: Significant differences were found between the seated position with instrument and without (p < 0.001, 0.03, 0.02 or 0.01) in the spine (trunk length, sagittal trunk decline, lumbar bending angle, maximal rotation, standard deviation rotation, lumbar lordosis), the shoulder (scapula distance, scapula rotation, scapula angle right) and pelvis distance.
Conclusions: Playing an instrument changes the static seating position by increased rotation of the spine and specific shoulder adaptations holding the instrument (left arm) and the bow (right arm), with minor effects on the pelvis. This forced position may result in chronic health effects. The method used in this study is an approach to better understand the involved muscular structures and possible resulting health damages.
Objective: Classifications of posture deviations are only possible compared with standard values. However, standard values have been published for healthy male adults but not for female adults.
Design: Observational study.
Setting: Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe-University Frankfurt/Main.
Participants: 106 healthy female volunteers (21–30 years old; 25.1±2.7 years) were included. Their body weight ranged from 46 to 106 kg (60.3±7.9 kg), the heights from 1.53 to 1.82 m (1.69±0.06 m) and the body mass index from 16.9 kg/m² to 37.6 kg/m² (21.1±2.6 kg/m²).
Outcome measures: A three-dimensional back scan was performed to measure the upper back posture in habitual standing. The tolerance ranges and CI were calculated. Group differences were tested by the Wilcoxon Mann-Whitney U test.
Results: In normal posture, the spinal column was marginally twisted to the left, and the vertebrae were marginally rotated to the right. The kyphosis angle is larger than the lumbar angle. Consequently, a more kyphotic posture is observed in the sagittal plane. The habitual posture is slightly scoliotic with a rotational component (scapular depression right, right scapula marginally more dorsally, high state of pelvic right, iliac right further rotated anteriorly).
Conclusions: Healthy young women have an almost ideally balanced posture with minimal ventral body inclination and a marginal scoliotic deviation. Compared with young males, women show only marginal differences in the upper body posture. These values allow a comparison to other studies, both for control and patient data, and may serve as guideline in both clinical practice and scientific studies.
Background: How a dentist works, such as the patterns of movements performed daily, is also largely affected by the workstation Dental tasks are often executed in awkward body positions, thereby causing a very high degree of strain on the corresponding muscles. The objective of this study is to detect those dental tasks, during which awkward postures occur most frequently. The isolated analysis of static postures will examine the duration for which these postures are maintained during the corresponding dental, respectively non-dental, activities.
Methods: 21 (11f/10 m) dentists (age: 40.1 ± 10.4 years) participated in this study. An average dental workday was collected for every subject. To collect kinematic data of all activities, the CUELA system was used. Parallel to the kinematic examination, a detailed computer-based task analysis was conducted. Afterwards, both data sets were synchronized based on the chronological order of the postures assumed in the trunk and the head region. All tasks performed were assigned to the categories "treatment" (I), "office" (II) and "other activities" (III). The angle values of each body region (evaluation parameter) were examined and assessed corresponding to ergonomic standards. Moreover, this study placed a particular focus on static positions, which are held statically for 4 s and longer.
Results: For "treatment" (I), the entire head and trunk area is anteriorly tilted while the back is twisted to the right, in (II) and (III) the back is anteriorly tilted and twisted to the right (non-neutral position). Static positions in (I) last for 4–10s, static postures (approx. 60%) can be observed while in (II) and (III) in the back area static positions for more than 30 s are most common. Moreover, in (II) the back is twisted to the right for more than 60 s in 26.8%.
Conclusion: Awkward positions are a major part of a dentists’ work. This mainly pertains to static positions of the trunk and head in contrast to "office work." These insights facilitate the quantitative description of the dentist profession with regard to the related physical load along with the health hazards to the musculoskeletal system. Moreover, the results allow for a selective extraction of the most unfavorable static body positions that dentists assume for each of the activities performed.
Background: This study aims at identifying orthodontic activities with the highest frequency of unfavorable/awkward and static postures held over a period of more than 4 s based on kinematic analysis. Moreover, a separate analysis of static postures for orthodontic and non-orthodontic activities serves to evaluate the duration for which these particular postures are assumed.
Methods: In total, 21 (13f/8 m) orthodontists (age: 31.5 ± 3.8 years) participated in this study. CUELA, a personal measurement system, was used to collect kinematic data for all orthodontic activities in a working day. Angle values of the head and torso were evaluated in accordance with ergonomic standards. Only those postures that were held statically for 4 s and longer were selected for further analysis. Alongside the kinematic analysis, the activities performed on-site were also subject to a detailed computerized analysis. The synchronization of data collected from both measurements arranges the patterns of posture found chronologically and in conjunction with the orthodontic activities performed ((I) "treatment" (II) "office" and (III) "other activities").
Results: For (I) we observed an anterior inclination of the head and torso area as well as a twist of the head and neck area to the right. We found anterior back inclination and lateral back torsion to the right for (II) and (III). If, furthermore, we differentiate the duration of static postures, there are primarily short to medium-term (4–30s) static postures identified for (I). Also, categories (II) and (III) predominantly demonstrate static back postures with a duration of up to 30 s. With regard to (II) we observed that the back is ventrally inclined for 10.1% of the total activity duration.
Conclusions: During treatment static strains are observed in the entire head and torso area. On the contrary, static postures prevalent in the torso area are essential for activities of the other categories, particularly office work. These findings allow for a careful selection of unfavorable and static postures for each of the activities performed and help to develop specific preventive measures.
Background: Up to 80% of breast cancer patients suffer from Cancer Related Cognitive Impairments (CRCI). Exercise is suggested as a potential supportive care option to reduce cognitive decline in cancer patients. This study will investigate the effects of a high-intensity interval endurance training (HIIT) on CRCI in breast cancer patients. Potentially underlying immunological and neurobiological mechanisms, as well as effects on patients’ self-perceived cognitive functioning and common cancer related side-effects, will be explored.
Methods: A single-blinded randomized controlled trial will be carried out. The impact of HIIT on CRCI will be compared to that of a placebo-intervention (supervised myofascial release training). Both interventions will be conducted simultaneously with the patients’ first-line chemotherapy treatment typically lasting 12–18 weeks. Fifty-nine women with breast cancer will be included in each of the two groups. The study is powered to detect (α = .05, β = .2) a medium effect size difference between the two groups (d = .5) in terms of patients’ change in cognitive testing performances, from baseline until the end of the exercise-intervention. The cognitive test battery, recommended by the International Cancer and Cognition Task Force to assess CRCI, will be used as primary measure. This includes the Hopkins Verbal Learning Test (learning/verbal memory), the Controlled Oral Word Association Test (verbal fluency) and the Trail-Making-Test A/B (attention/set-switching). The following endpoints will be assessed as secondary measures: Go-/No-Go test performance (response inhibition), self-perceived cognitive functioning, serum levels of pro- and antiinflammatory markers (tumor necrosis factor alpha, Interleukin-6, Interleukin-1 alpha, Interleukin-1 beta, C-reactive protein, Interleukin-1 receptor antagonist and Interleukin-10), serum levels of neurotrophic and growth factors (brain-derived neurotrophic factor, insulin-like growth factor 1 and vascular endothelial growth factor), as well as common cancer-related side effects (decrease in physical capacity, fatigue, anxiety and depression, sleep disturbances, quality of life and chemotherapy compliance).
Discussion: This study will provide data on the question whether HIIT is an effective supportive therapy that alleviates CRCI in breast cancer patients. Moreover, the present study will help shed light on the underlying mechanisms of potential CRCI improving effects of exercise in breast cancer patients.
Trial registration: DRKS.de, German Clinical Trials Register (DRKS), ID: DRKS00011390, Registered on 17 January 2018.
Motion analysis in the field of dentistry : a kinematic comparison of dentists and orthodontists
(2016)
Objectives: To conduct a kinematic comparison of occupational posture in orthodontists and dentists in their workplace.
Design: Observational study.
Setting: Dentist surgeries and departments of orthodontics at university medical centres in Germany.
Participants: A representative sample of 21 (10 female, 11 male) dentists (group G1) and 21 (13 female, 8 male) orthodontists (G2) with one male dropout in G2.
Outcome measures: The CUELA (computer-assisted acquisition and long-term analysis of musculoskeletal loads) system was used to analyse occupational posture. Parallel to the recording through the CUELA system, a software-supported analysis of the activities performed (I: treatment; II: office; III: other activities) was carried out. In line with ergonomic standards the measured body angles are categorised into neutral, moderate and awkward postures. Activities between the aforementioned groups are compared using the stratified van Elteren U test and the Wilcoxon–Mann–Whitney U test. All p values are subject to the Bonferroni–Holm correction. The level of significance is set at 5%.
Results: The percentage of time spent on activities in categories I–II–III was as follows: dentists 41%–23%–36% and orthodontists 28%–37%–35%. The posture analysis of both groups showed, for all percentiles (P5–95), angle values primarily in the neutral or moderate range. However, depending on the activity performed, between 5% and 25% of working hours were spent in unfavourable postures, especially in the head-and-neck area. Orthodontists have a greater tendency than dentists to perform treatment activities with the head and torso in unfavourable positions. The statistically significant differences between the two groups with regard to the duration and the relevance of the activities performed confirm this assumption for all three categories (p<0.01, p<0.05).
Conclusions: Generally, both groups perform treatment activities in postures that are in the neutral or medium range; however, dentists had slightly more unfavourable postures during treatment for a greater share of their work day.
Background: Arising from the relevance of sensorimotor training in the therapy of nonspecific low back pain patients and from the value of individualized therapy, the present trial aims to test the feasibility and efficacy of individualized sensorimotor training interventions in patients suffering from nonspecific low back pain.
Methods and study design: A multicentre, single-blind two-armed randomized controlled trial to evaluate the effects of a 12-week (3 weeks supervised centre-based and 9 weeks home-based) individualized sensorimotor exercise program is performed. The control group stays inactive during this period. Outcomes are pain, and pain-associated function as well as motor function in adults with nonspecific low back pain. Each participant is scheduled to five measurement dates: baseline (M1), following centre-based training (M2), following home-based training (M3) and at two follow-up time points 6 months (M4) and 12 months (M5) after M1. All investigations and the assessment of the primary and secondary outcomes are performed in a standardized order: questionnaires – clinical examination – biomechanics (motor function). Subsequent statistical procedures are executed after the examination of underlying assumptions for parametric or rather non-parametric testing.
Discussion: The results and practical relevance of the study will be of clinical and practical relevance not only for researchers and policy makers but also for the general population suffering from nonspecific low back pain.
Background: We aimed to investigate the potential effects of a 4-week motor–cognitive dual-task training on cognitive and motor function as well as exercise motivation in young, healthy, and active adults.
Methods: A total of 26 participants (age 25 ± 2 years; 10 women) were randomly allocated to either the intervention group or a control group. The intervention group performed a motor–cognitive training (3×/week), while the participants of the control group received no intervention. Before and after the intervention period of 4 weeks, all participants underwent cognitive (d2-test, Trail Making Test) and motor (lower-body choice reaction test and time to stabilization test) assessments. Following each of the 12 workouts, self-reported assessments (rating of perceived exertion, enjoyment and pleasant anticipation of the next training session) were done. Analyses of covariances and 95% confidence intervals plotting for between group and time effects were performed.
Results: Data from 24 participants were analysed. No pre- to post-intervention improvement nor a between-group difference regarding motor outcomes (choice-reaction: F = 0.5; time to stabilization test: F = 0.7; p > 0.05) occurred. No significant training-induced changes were found in the cognitive tests (D2: F = 0.02; Trail Making Test A: F = 0.24; Trail Making Test B: F = 0.002; p > 0.05). Both enjoyment and anticipation of the next workout were rated as high.
Discussion: The neuro-motor training appears to have no significant effects on motor and cognitive function in healthy, young and physically active adults. This might be explained in part by the participants’ very high motor and cognitive abilities, the comparably low training intensity or the programme duration. The high degree of exercise enjoyment, however, may qualify the training as a facilitator to initiate and maintain regular physical activity. The moderate to vigorous intensity levels further point towards potential health-enhancing cardiorespiratory effects.
Background: Although anterior cruciate ligament (ACL) tear-prevention programs may be effective in the (secondary) prevention of a subsequent ACL injury, little is known, yet, on their effectiveness and feasibility. This study assesses the effects and implementation capacity of a secondary preventive motor-control training (the Stop-X program) after ACL reconstruction.
Methods and design: A multicenter, single-blind, randomized controlled, prospective, superiority, two-arm design is adopted. Subsequent patients (18–35 years) with primary arthroscopic unilateral ACL reconstruction with autologous hamstring graft are enrolled. Postoperative guideline rehabilitation plus Classic follow-up treatment and guideline rehabilitation plus the Stop-X intervention will be compared. The onset of the Stop-X program as part of the postoperative follow-up treatment is individualized and function based. The participants must be released for the training components. The endpoint is the unrestricted return to sport (RTS) decision. Before (where applicable) reconstruction and after the clearance for the intervention (aimed at 4–8 months post surgery) until the unrestricted RTS decision (but at least until 12 months post surgery), all outcomes will be assessed once a month. Each participant is consequently measured at least five times to a maximum of 12 times. Twelve, 18 and 24 months after the surgery, follow-up-measurements and recurrence monitoring will follow. The primary outcome assessement (normalized knee-separation distance at the Drop Jump Screening Test (DJST)) is followed by the functional secondary outcomes assessements. The latter consist of quality assessments during simple (combined) balance side, balance front and single-leg hops for distance. All hop/jump tests are self-administered and filmed from the frontal view (3-m distance). All videos are transferred using safe big content transfer and subsequently (and blinded) expertly video-rated. Secondary outcomes are questionnaires on patient-reported knee function, kinesiophobia, RTS after ACL injury and training/therapy volume (frequency – intensity – type and time). All questionnaires are completed online using the participants’ pseudonym only.
Group allocation is executed randomly. The training intervention (Stop-X arm) consists of self-administered home-based exercises. The exercises are step-wise graduated and follow wound healing and functional restoration criteria. The training frequency for both arms is scheduled to be three times per week, each time for a 30 min duration. The program follows current (secondary) prevention guidelines.
Repeated measurements gain-score analyses using analyses of (co-)variance are performed for all outcomes.
Trial registration: German Clinical Trials Register, identification number DRKS00015313. Registered on 1 October 2018.
Patienten mit chronisch-unspezifischen Nackenschmerzen weisen Studien zufolge ein gegenüber symptomfreien Personen pathologisch verändertes Bewegungsverhalten der Halswirbelsäule auf. Aktuelle Untersuchungen bestätigen dabei eine im Vergleich zu gesunden, symptomfreien Probanden verminderte Beweglichkeit der Zervikalregion. Mit dem Fokus auf sensomotorische Funktionen deuten Studien zudem ein erhöhtes Maß an nicht-intendierter Bewegungsvariabilität sowie ein vermindertes Maß an Nebenbewegungen in andere Ebenen bei der Durchführung zweidimensionaler Bewegungsabfolgen an. Demgegenüber verändert sich bei symptomfreien Personen das zervikale Bewegungs-verhalten im Altersverlauf. Aktuelle Untersuchungen indizieren dabei eine im Alter erhöhte Bewegungsvariabilität. Zusätzlich indizieren Studien ein mit zunehmendem Alter geringer werdendes maximales Bewegungsausmaß der Halswirbelsäule. Publizierte Normwerte drücken diese altersabhängigen Veränderungen jedoch nur grob kategorisierend für größere Altersspannen aus. Daten zu möglichen Zuordnungsmöglichkeiten von Patienten und gesunden Personen anhand trennscharfer Schwellenwerten zum Bewegungsausmaß und zur Bewegungskonsistenz fehlen gänzlich.Vor diesem Hintergrund war das Ziel der Studie die Entwicklung und Validierung klassifikatorischer Modelle zur Diskriminierung von symptomatischem und asympto-matischem zervikalem Bewegungsverhalten. Symptomfreie Probanden (120) wurden konsekutiv der Modellentwicklung (n = 100, 18 – 75 Jahre, 36 f) bzw. der Modellvalidierung zugeteilt (n = 20, 23 – 75 Jahre, 15 f). Zusätzlich wurden zur Modellvalidierung ebenfalls 20 Patienten mit chronisch-unspezifischen Nackenschmerzen eingeschlossen (22 – 71 Jahre, 15 f). Alle Probanden absolvierten initial eine Bewegungsanalyse zur Erhebung des Bewegungsverhaltens der Halswirbelsäule. Diese beinhaltet ein Set zu fünf repetitiven zervikalen Flexions-/Extensions-Bewegungszyklen. Die kinematischen Variablen wurden dabei ultraschalltopometrisch erfasst. Diese standardisierte Erhebung erfolgte in stabiler aufrechter Positionierung und selbstgewählter Geschwindigkeit unter Verwendung eines nichtinvasiven 3D-Bewegungsanalysesystems. Die kinematischen Charakteristika, bestehend aus maximalem Bewegungsausmaß in der Sagittalebene (ROM), den Variationskoeffizienten (CV) sowie den mittleren Nebenbewegungen in Frontal- und Transversalebene (NEB) wurden final aus den Rohdaten berechnet. Im Anschluss erfolgte die Modellentwicklung auf Basis von Cut-Offs. Dies geschah mittels der Erstellung von voraussetzungskonformen linearen Regressionsmodellen. Unabhängige Variable war dabei das Alter, die abhängige Variable stellte das jeweilige kinematische Charakteristikum dar. Die Cut-Offs beschrieben jeweils die Prognose-Konfidenzintervalle der Regressionsgeraden (90% Prognose-Konfidenzintervall für individuelle Werte (ind) und 95% Prognose-Konfidenzintervall für Mittelwerte (MW)). Die Werte der kinematischen Analyse jedes Probanden, der in die Modellvalidierung der entwickelten Cut-Offs eingeschlossen wurde, wurden anschließend mittels dieser Cut-Offs klassifiziert als ‘asymptomatisch’ oder ‘symptomatisch’. Auf der Basis dieser Zuteilung wurden die Cut-Offs stringent mittels Vierfeldertafeln auf ihre Trennschärfe in der Diskriminierung von chronisch-unspezifischen Nackenschmerzpatienten und symptomfreien Personen überprüft. Alle entwickelten Modelle wiesen einen gerichteten linearen Zusammenhang zwischen Alter und dem jeweiligen kinematischen Charakteristikum auf. Auf Basis der internen Validierung beinhaltet das 95%-Konfidenzintervall der Steigung der Regressionsgeraden in dem vorliegenden Modell den Nullwert nicht und schließt zudem bei allen drei Modellen die bei der Erstellung des Modells gefundene Steigung ein. Bei der Modellvalidierung ergab die Bewertung der Vierfeldertafeln überzufällige Unterschiede zwischen erwarteter und beobachteter Häufigkeitsverteilung der mittels Prognose-Konfidenzintervalle für Mittelwerte für ROM (ROMMW; Chi2= 6.8; p< .01) und CV (CVMW; Chi2= 6.42; p< .05) klassierten kinematischen Größen, nicht jedoch für die vier anderen Klassifikatoren (p> .05). Im Anschluss ergab die Analyse der Trennschärfe der Modelle mit überzufälliger Merkmalsverteilung eine Sensitivität von 60 % für ROMMW und von 75 % für CVMW. Die Spezifität betrug 85 % für ROMMW und 65 % für CVMW. Die Resultate demonstrieren einerseits einen linearen Zusammenhang von Alter und verschiedener kinematischer Charakteristika sowie eine überzufällige Merkmalsverteilung für die Modelle ROMMW und CVMW mit ausreichender Spezifität und Sensitivität und – daraus hervorgehend – eine ausreichende Trennschärfe der klassifikatoren in der Differenzierung von symptomatischen und asymptomatischen Bewegungsmustern. Die Resultate sind einerseits im Einklang mit anderen – kategorisierenden – Studienresultaten und ergänzen andererseits – durch die Erstellung und Bewertung trennscharfer Klassifikatoren – den aktuellen Forschungsstand konsekutiv. Die Trennschärfe-Indizes bewegen sich dabei in vergleichbarer Größenordnung wie andere (subjektive) Klassifikatoren (z.B. Schmerzstärke) zur Einordnung von Nackenschmerzpatienten. Insbesondere in der individuellen Beurteilung, aber auch für mögliche prospektive Vergleiche sind valide Ein ordnungskriterien von Belangen und bieten gegenüber einfachen kategorisierenden Gruppenwerten genauere und verlässlichere Klassierungen. Zukünftige Forschungsaktivitäten sollten sich insbesondere mit der Übertragbarkeit vorliegender Cut-Offs auf interventionsinduzierte individuelle Veränderungen auseinandersetzen.
Stabilization exercise (SE) is evident for the management of chronic non-specific low back pain (LBP). The optimal dose-response-relationship for the utmost treatment success is, thus, still unknown. The purpose is to systematically review the dose-response-relationship of stabilisation exercises on pain and disability in patients with chronic non-specific LBP. A systematic review with meta-regression was conducted (Pubmed, Web of Knowledge, Cochrane). Eligibility criteria were RCTs on patients with chronic non-specific LBP, written in English/German and adopting a longitudinal core-specific/stabilising/motor control exercise intervention with at least one outcome for pain intensity and/or disability. Meta-regressions (dependent variable = effect sizes (Cohens d) of the interventions (for pain and for disability), independent variable = training characteristics (duration, frequency, time per session)), and controlled for (low) study quality (PEDro) and (low) sample sizes (n) were conducted to reveal the optimal dose required for therapy success. From the 3,415 studies initially selected, 50 studies (n = 2,786 LBP patients) were included. N = 1,239 patients received SE. Training duration was 7.0 ± 3.3 weeks, training frequency was 3.1 ± 1.8 sessions per week with a mean training time of 44.6 ± 18.0 min per session. The meta-regressions’ mean effect size was d = 1.80 (pain) and d = 1.70 (disability). Total R2 was 0.445 and 0.17. Moderate quality evidence (R2 = 0.231) revealed that a training duration of 20 to 30 min elicited the largest effect (both in pain and disability, logarithmic association). Low quality evidence (R2 = 0.125) revealed that training 3 to 5 times per week led to the largest effect of SE in patients with chronic non-specific LBP (inverted U-shaped association). In patients with non-specific chronic LBP, stabilization exercise with a training frequency of 3 to 5 times per week (Grade C) and a training time of 20 to 30 min per session (Grade A) elicited the largest effect on pain and disability.
Aim of the study: Investigation, whether water-filtered infrared-A (wIRA) irradiation during moderate bicycle ergometer endurance exercise has effects especially on local fat reduction and on weight reduction beyond the effects of ergometer exercise alone.
Methods: Randomised controlled study with 40 obese females (BMI 30-40 (median: 34.5), body weight 76-125 (median: 94.9) kg, age 20-40 (median: 35.5) years, isocaloric nutrition), 20 in the wIRA group and 20 in the control group. In both groups each participant performed 3 times per week over 4 weeks for 45 minutes bicycle ergometer endurance exercise with a constant load according to a lactate level of 2 mmol/l (aerobic endurance load, as determined before the intervention period). In the wIRA group in addition large parts of the body (including waist, hip, and thighs) were irradiated during all ergometries of the intervention period with visible light and a predominant part of water-filtered infrared-A (wIRA), using the irradiation unit “Hydrosun® 6000” with 10 wIRA radiators (Hydrosun® Medizintechnik, Müllheim, Germany, radiator type 500, 4 mm water cuvette, yellow filter, water-filtered spectrum 500-1400 nm) around a speed independent bicycle ergometer.
Main variable of interest: change of “the sum of circumferences of waist, hip, and both thighs of each patient” over the intervention period (4 weeks). Additional variables of interest: body weight, body mass index BMI, body fat percentage, fat mass, fat-free mass, water mass (analysis of body composition by tetrapolar bioimpedance analysis), assessment of an arteriosclerotic risk profile by blood investigation of variables of lipid metabolism (cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL, apolipoprotein A1, apolipoprotein B), clinical chemistry (fasting glucose, alanin-aminotransferase ALT (= glutamyl pyruvic transaminase GPT), gamma-glutamyl-transferase GGT, creatinine, albumin), endocrinology (leptin, adiponectin (= adipo Q), homocysteine, insulin). All variables were at least measured before and after the intervention period. Ergometry (ECG, blood pressure behaviour, lactate curve with power at 2, 3 and 4 mmol/l) before the intervention period. In addition: nutrition training ahead of and during the intervention period with a nutrition protocol over one week for assessment of the daily energy intake; calculation of basic metabolic rate and total energy requirement. Assessment of undesired effects.
Only methods of non-parametric statistics were used, both descriptive (median, percentiles of 25 and 75 (= interquartile range), minimum, maximum) and confirmatory (two-sided Mann-Whitney U test for unpaired samples for the only one main variable of interest). Total error probability: .05 (5%). An intention to treat analysis ITT with last observed carry forward method was used preferably (presented results) and in addition an on treatment analysis OT. Only 2 (treatment group) and 4 (control group) drop-outs occurred (mostly due to lack of time).
Results: The “sum of circumferences of waist, hip, and both thighs of each patient” decreased during the 4 weeks significantly more (p<.001) in the wIRA group than in the control group: medians and interquartile ranges: -8.0 cm (-10.5 cm/-4.1 cm) vs. -1.8 cm (-4.4 cm/0.0 cm).
As well “body weight of each patient” decreased during the 4 weeks markedly more in the wIRA group than in the control group: medians and interquartile ranges: -1.9 kg (-4.0 kg/0.0 kg) vs. 0.0 kg (-1.5 kg/+0.4 kg); median of body weight changed from 99.3 kg to 95.6 kg (wIRA) vs. 89.9 kg to 89.6 kg (control). A similar effect showed the body mass index BMI.
Blood variables of interest remained unchanged or showed some slight improvements during the treatment period, concerning most variables with no obvious differences between the two groups; insulin showed a slight trend to decrease in the wIRA group and to increase in the control group.
Undesired effects of the treatment were not seen.
Discussion: The results of the study suggest, that wIRA – during moderate bicycle ergometer endurance exercise as lipolytic stimulus – increases local lipolysis with a local fat reduction (thighs) in the otherwise bradytrophic fatty tissue. The presumably underlying mechanisms of wIRA have already been proven: wIRA acts both by thermal effects and by non-thermal effects. Thermal effects of wIRA are the generation of a therapeutic field of warmth with the increase of tissue temperature, tissue oxygen partial pressure, and tissue blood flow, and by this regional metabolism. As fatty tissue normally has a slow metabolism (bradytrophic and hypothermic tissue) with a low rate of lipolysis, wIRA can increase lipolysis in fatty tissue and the mobilized fats are burned in musculature during the ergometer exercise.
Conclusion: The results of the study indicate, that wIRA irradiation during moderate ergometer endurance exercise can be used – in combination with an appropriate nutrition – to improve body composition, especially local fat distribution, and the reduction of fat and body weight in obese persons.
Keywords: water-filtered infrared-A (wIRA), weight reduction, local fat reduction, bicycle ergometer endurance exercise, lipolysis, randomised controlled study, intervention trial, body weight, body mass index BMI, analysis of body composition, tetrapolar bioimpedance analysis, lactate, lipid metabolism, cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL
Aim of the study: Investigation, whether water-filtered infrared-A (wIRA) irradiation during moderate bicycle ergometer endurance exercise has effects especially on local fat reduction and on weight reduction beyond the effects of ergometer exercise alone.
Methods: Randomised controlled study with 40 obese females (BMI 30-40 (median: 34.5), body weight 76-125 (median: 94.9) kg, age 20-40 (median: 35.5) years, isocaloric nutrition), 20 in the wIRA group and 20 in the control group. In both groups each participant performed 3 times per week over 4 weeks for 45 minutes bicycle ergometer endurance exercise with a constant load according to a lactate level of 2 mmol/l (aerobic endurance load, as determined before the intervention period). In the wIRA group in addition large parts of the body (including waist, hip, and thighs) were irradiated during all ergometries of the intervention period with visible light and a predominant part of water-filtered infrared-A (wIRA), using the irradiation unit “Hydrosun® 6000” with 10 wIRA radiators (Hydrosun® Medizintechnik, Müllheim, Germany, radiator type 500, 4 mm water cuvette, yellow filter, water-filtered spectrum 500-1400 nm) around a speed independent bicycle ergometer.
Main variable of interest: change of “the sum of circumferences of waist, hip, and both thighs of each patient” over the intervention period (4 weeks). Additional variables of interest: body weight, body mass index BMI, body fat percentage, fat mass, fat-free mass, water mass (analysis of body composition by tetrapolar bioimpedance analysis), assessment of an arteriosclerotic risk profile by blood investigation of variables of lipid metabolism (cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL, apolipoprotein A1, apolipoprotein B), clinical chemistry (fasting glucose, alanin-aminotransferase ALT (= glutamyl pyruvic transaminase GPT), gamma-glutamyl-transferase GGT, creatinine, albumin), endocrinology (leptin, adiponectin (= adipo Q), homocysteine, insulin). All variables were at least measured before and after the intervention period. Ergometry (ECG, blood pressure behaviour, lactate curve with power at 2, 3 and 4 mmol/l) before the intervention period. In addition: nutrition training ahead of and during the intervention period with a nutrition protocol over one week for assessment of the daily energy intake; calculation of basic metabolic rate and total energy requirement. Assessment of undesired effects.
Only methods of non-parametric statistics were used, both descriptive (median, percentiles of 25 and 75 (= interquartile range), minimum, maximum) and confirmatory (two-sided Mann-Whitney U test for unpaired samples for the only one main variable of interest). Total error probability: .05 (5%). An intention to treat analysis ITT with last observed carry forward method was used preferably (presented results) and in addition an on treatment analysis OT. Only 2 (treatment group) and 4 (control group) drop-outs occurred (mostly due to lack of time).
Results: The “sum of circumferences of waist, hip, and both thighs of each patient” decreased during the 4 weeks significantly more (p<.001) in the wIRA group than in the control group: medians and interquartile ranges: -8.0 cm (-10.5 cm/-4.1 cm) vs. -1.8 cm (-4.4 cm/0.0 cm).
As well “body weight of each patient” decreased during the 4 weeks markedly more in the wIRA group than in the control group: medians and interquartile ranges: -1.9 kg (-4.0 kg/0.0 kg) vs. 0.0 kg (-1.5 kg/+0.4 kg); median of body weight changed from 99.3 kg to 95.6 kg (wIRA) vs. 89.9 kg to 89.6 kg (control). A similar effect showed the body mass index BMI.
Blood variables of interest remained unchanged or showed some slight improvements during the treatment period, concerning most variables with no obvious differences between the two groups; insulin showed a slight trend to decrease in the wIRA group and to increase in the control group.
Undesired effects of the treatment were not seen.
Discussion: The results of the study suggest, that wIRA – during moderate bicycle ergometer endurance exercise as lipolytic stimulus – increases local lipolysis with a local fat reduction (thighs) in the otherwise bradytrophic fatty tissue. The presumably underlying mechanisms of wIRA have already been proven: wIRA acts both by thermal effects and by non-thermal effects. Thermal effects of wIRA are the generation of a therapeutic field of warmth with the increase of tissue temperature, tissue oxygen partial pressure, and tissue blood flow, and by this regional metabolism. As fatty tissue normally has a slow metabolism (bradytrophic and hypothermic tissue) with a low rate of lipolysis, wIRA can increase lipolysis in fatty tissue and the mobilized fats are burned in musculature during the ergometer exercise.
Conclusion: The results of the study indicate, that wIRA irradiation during moderate ergometer endurance exercise can be used – in combination with an appropriate nutrition – to improve body composition, especially local fat distribution, and the reduction of fat and body weight in obese persons.
Das Phänomen der Bewegungsvariabilität erfährt in den letzten Jahren ein gesteigertes Interesse. Die Betrachtung von Modellen der Motorik zeigt, dass innerhalb traditioneller Theorien Variationen in der Bewegungsausführung als Fehler des Systems aufgefasst werden, während aktuellere Theorien Variabilität als dem System inhärente Erscheinung und als möglichen Kompensationsmechanismus betrachten. Eine Operationalisierung der Variabilität als Messwert ist abhängig vom theoretischen Ausgangspunkt. Nichtlineare und klassische Auswerteverfahren – wie die detrended fluctuation analysis, die Standardabweichung, der Variationskoeffizient, u.a. – schließen sich jedoch keinesfalls aus, sondern können sich in der Erweiterung des Verständnisses der zugrundeliegenden physiologischen Mechanismen ergänzen. In der empirischen Untersuchung wurde geprüft, ob der Einsatz von dreidimensionalen Beschleunigungsaufnehmern in der Ganganalyse die Möglichkeit bietet – neben den schon in diversen Untersuchungen dargestellten Schrittzyklusdauer und Schrittbreite – weitere Teilaspekte der Bewegung zu beschreiben und insbesondere deren Variabilität nicht ausschließlich über eine Aneinanderreihung von diskreten Werten, die jeweils einen einzelnen Zyklus abbilden, zu betrachten. 48 Sportstudenten gingen hierzu 20 bis 25 Minuten kontinuierlich, bei selbstgewählter Geschwindigkeit, die nicht willentlich verändert werden sollte, und ebenem Untergrund. Dabei trugen sie an jedem Fuß jeweils einen triaxialen Beschleunigungssensor am distalen Ende des Os metatarsale III und unterhalb des Malleolus lateralis. Über zwei Doppellichtschranken wurde die Lokomotionsgeschwindigkeit der Probanden erfasst. Anhand des Fersenkontaktes wurden die Beschleunigungs-Zeitverläufe der Versuchspersonen in einzelne Schrittzyklen getrennt und deren Dauer bestimmt. Außerdem wurde die Dauer der Stand- und Schwungphase sowie die double-support-time identifiziert. Die einzelnen Schrittzyklen pro Versuchsperson wurden zeitnormiert und für jede Achse getrennt aufsummiert, um eine ensemble-averagecurve (Punkt zu Punkt Verfahren) zu erstellen. Aus den Standardabweichungen in Allen drei Achsen wurde darüber hinaus ein Variabilitätsquader für jeden Zeitpunkt des Schrittzyklus berechnet. Diese wurden für die bereits angesprochen Phasen zusammengefasst und auf Unterschiede geprüft. Die statistische Analyse ergab, dass sich die Variabilität im Raum zwischen den Phasen signifikant unterscheidet (Signifikanzniveau 0,05), jedoch keine Unterschiede zwischen der rechten und der linken Seite bestanden. Für die Zeitreihen, die aus der Schrittzyklus-, Standphasen- und Schwungphasendauer sowie den double-support-times zusammengesetzt waren, wurde eine detrended fluctuation analysis durchgeführt. Der Vergleich dieser Zeitreihen mit fiktiven Zeitreihen, die die gleicheStandardabweichung und den gleichen Mittelwert allerdings eine andere zeitliche Struktur aufwiesen, zeigte, dass die Zeitreihen Langzeitkorrelationen aufwiesen. Für die Schrittzyklusdauer liegen die α-Werte mit im Gruppendurchschnitt 0,856 im Bereich derer, die in der Literatur für Normalpersonen zu finden sind. Die α-Werte für die Stand- (0,776) und Schwungphasendauer (0,656) sowie die double-support-time (0,624) können nicht mit anderen Untersuchungen verglichen werden, da – soweit bekannt – keine weiteren Studien existieren, die diese Parameter mittels DFA untersucht haben. Die Ursache der Bewegungsvariabilität – innerhalb der mechanisch zulässigen Grenzen – entsteht innerhalb des neuronalen Systems. Zytologisch lassen sich ca. 100 verschiedene Neuronentypen klassifizieren. Die Vielfalt der Ionenkanalausprägung ist allerdings noch größer. Leckströme, ungerichtete Ausschüttung von Transmittern, Veränderungen des Zellvolumens, transzelluläre Boten u.a. sind für Schwankungen der intra- und extrazellulären Ionenkonzentrationen und somit für die Fluktuationen des Membranpotentials einer Nervenzelle verantwortlich. Auch die synaptische Übertragung ist variabel: Das gleiche präsynaptische Potential sorgt nicht für die Ausschüttung der gleichen Menge an Vesikeln. Auch die Wirkung des Neurotransmitters an der postsynaptischen Membran ist von diversen Mechanismen modulierbar. Aus energetischer Sicht muss man das Henneman-Prinzip für die Rekrutierung von motorischen Einheiten innerhalb des Motoneuronenpools nach Größe in Frage stellen. Ohne weitere modulierende Faktoren würden bei wiederholter Ausführung einer submaximalen Belastung immer die gleichen motorischen Einheiten aktiviert. In Abhängigkeit der Intensität und der metabolischen Ausgangssituation würde eben dies über kurz oder lang zu einer Ermüdung führen. Dies jedoch stellt eine Gefährdung des Organismus dar. Eine Rotation in der Rekrutierungsreihenfolge der Motoneurone könnte einer Ermüdung vorbeugen. Da nun aber nicht alle Muskelfasern exakt parallel vom Ansatz zum Ursprung verlaufen, würde im Falle einer solchen Rotation gegebenenfalls zwar die gleiche Kraft, aber eventuell in leicht veränderter Richtung produziert. Es ist davon auszugehen, dass dies einen Teil derbeobachtbaren Variabilität darstellt. Aus Sicht der Sensorik ist Variabilität zu begrüßen. Wiederkehrende Reize haben keinerlei Neuigkeitswert und werden demnach schnell nicht mehr detektiert. Die Interaktion mit der Umwelt setzt aber eine möglichst präzise und umfangreiche sensorische Wahrnehmung voraus. Produziert nun die Motorik Variabilität, die dafür sorgt , dass die Sensorik ihre Detektionsqualität steigern oder zumindest länger aufrecht erhalten kann, so stellt dies eine Win-Win Situation dar.
Background: Water-filtered infrared-A (wIRA) is a special form of heat radiation with a high tissue-penetration and with a low thermal burden to the surface of the skin. wIRA is able to improve essential and energetically meaningful factors of wound healing by thermal and non-thermal effects.
Aim of the study: prospective study (primarily planned randomised, controlled, blinded, de facto with one exception only one cohort possible) using wIRA in the treatment of patients with recalcitrant chronic venous stasis ulcers of the lower legs with thermographic follow-up.
Methods: 10 patients (5 males, 5 females, median age 62 years) with 11 recalcitrant chronic venous stasis ulcers of the lower legs were treated with water-filtered infrared-A and visible light irradiation (wIRA(+VIS), Hydrosun® radiator type 501, 10 mm water cuvette, water-filtered spectrum 550–1400 nm) or visible light irradiation (VIS; only possible in one patient). The uncovered wounds of the patients were irradiated two to five times per week for 30 minutes at a standard distance of 25 cm (approximately 140 mW/cm2 wIRA and approximately 45 mW/cm2 VIS). Treatment continued for a period of up to 2 months (typically until closure or nearly closure of the ulcer). The main variable of interest was “percent change of ulcer size over time” including complete wound closure. Additional variables of interest were thermographic image analysis, patient’s feeling of pain in the wound, amount of pain medication, assessment of the effect of the irradiation (by patient and by clinical investigator), assessment of feeling of the wound area (by patient), assessment of wound healing (by clinical investigator) and assessment of the cosmetic state (by patient and by clinical investigator). For these assessments visual analogue scales (VAS) were used.
Results: The study showed a complete or nearly complete healing of lower leg ulcers in 7 patients and a clear reduction of ulcer size in another 2 of 10 patients, a clear reduction of pain and pain medication consumption (e.g. from 15 to 0 pain tablets per day), and a normalization of the thermographic image (before the beginning of the therapy typically hyperthermic rim of the ulcer with relative hypothermic ulcer base, up to 4.5°C temperature difference). In one patient the therapy of an ulcer of one leg was performed with the fully active radiator (wIRA(+VIS)), while the therapy of an ulcer of the other leg was made with a control group radiator (only VIS without wIRA), showing a clear difference in favour of the wIRA treatment. All mentioned VAS ratings improved remarkably during the period of irradiation treatment, representing an increased quality of life. Failures of complete or nearly complete wound healing were seen only in patients with arterial insufficiency, in smokers or in patients who did not have venous compression garment therapy.
Discussion and conclusions: wIRA can alleviate pain considerably (with an impressive decrease of the consumption of analgesics) and accelerate wound healing or improve a stagnating wound healing process and diminish an elevated wound exudation and inflammation both in acute and in chronic wounds (in this study shown in chronic venous stasis ulcers of the lower legs) and in problem wounds including infected wounds. In chronic recalcitrant wounds complete healing is achieved, which was not reached before. Other studies have shown that even without a disturbance of wound healing an acute wound healing process can be improved (e.g. reduced pain) by wIRA.
wIRA is a contact-free, easily used and pleasantly felt procedure without consumption of material with a good penetration effect, which is similar to solar heat radiation on the surface of the earth in moderate climatic zones. Wound healing and infection defence (e.g. granulocyte function including antibacterial oxygen radical formation of the granulocytes) are critically dependent on a sufficient energy supply (and on sufficient oxygen). The good clinical effect of wIRA on wounds and also on problem wounds and wound infections can be explained by the improvement of both the energy supply and the oxygen supply (e.g. for the granulocyte function). wIRA causes as a thermal effect in the tissue an improvement in three decisive factors: tissue oxygen partial pressure, tissue temperature and tissue blood flow. Besides this non-thermal effects of infrared-A by direct stimulation of cells and cellular structures with reactions of the cells have also been described. It is concluded that wIRA can be used to improve wound healing, to reduce pain, exudation, and inflammation and to increase quality of life.
Objective: The influence of the jaw position on postural control, body posture, walking and running pattern has been reported in the literature. All these movements have in common that a relatively small, but well controlled muscle activation is required. The induced effects on motor output through changed jaw positions have been small. Therefore, it has been questioned if it could still be observed in maximal muscle activation.
Method: Twenty-three healthy, mid age recreational runners (mean age = 34.0 ± 10.3 years) participated in this study. Three different jump tests (squat jump, counter movement jump, and drop jumps from four different heights) and three maximal strength tests (trunk flexion and extension, leg press of the right and left leg) were conducted. Four different dental occlusion conditions and an additional familiarization condition were tested. Subjects performed the tests on different days for which the four occlusion conditions were randomly changed.
Results: No familiarization effect was found. Occlusion conditions with a relaxation position and with a myocentric condylar position showed significantly higher values for several tests compared to the neutral condition and the maximal occlusion position. Significance was found in the squat jump, countermovement jump, the drop jump from 32cm and 40cm, trunk extension, leg press force and rate of force development. The effect due to the splint conditions is an improvement between 3% and 12% (min and max). No influence of the jaw position on symmetry or balance between extension and flexion muscle was found.
Conclusion: An influence of occlusion splints on rate of force development (RFD) and maximal strength tests could be confirmed. A small, but consistent increase in the performance parameters could be measured. The influence of the occlusion condition is most likely small compared to other influences as for example training status, age, gender and circadian rhythm.
There is mounting evidence that aerobic exercise has a positive effect on cognitive functions in older adults. To date, little is known about the neurometabolic and molecular mechanisms underlying this positive effect. The present study used magnetic resonance spectroscopy and quantitative MRI to systematically explore the effects of physical activity on human brain metabolism and grey matter (GM) volume in healthy aging. This is a randomised controlled assessor-blinded two-armed trial (n=53) to explore exercise-induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age >65) were allocated to a 12-week individualised aerobic exercise programme intervention (n=29) or a 12-week waiting control group (n=24). The main outcomes were the change in cerebral metabolism and its association to brain-derived neurotrophic factor (BDNF) levels as well as changes in GM volume. We found that cerebral choline concentrations remained stable after 12 weeks of aerobic exercise in the intervention group, whereas they increased in the waiting control group. No effect of training was seen on cerebral N-acetyl-aspartate concentrations, nor on markers of neuronal energy reserve or BDNF levels. Further, we observed no change in cortical GM volume in response to aerobic exercise. The finding of stable choline concentrations in the intervention group over the 3 month period might indicate a neuroprotective effect of aerobic exercise. Choline might constitute a valid marker for an effect of aerobic exercise on cerebral metabolism in healthy aging.