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Muskelskelett-Erkrankungen (MSE) bei Büroangestellten sind häufig mit einer höheren Muskelspannung und einer eingeschränkten Bewegungsreichweite assoziiert. Ein hohes präventives Potential haben daher Dehntrainings, da durch eine muskuläre Relaxation die Muskelspannung reduziert werden kann und gleichzeitig auf psychischer Ebene eine Möglichkeit zur Entspannung geboten wird. Auch im Rahmen von Maßnahmen der betrieblichen Gesundheitsförderung (BGF), die im Kontext der Arbeitsmedizin immer mehr an Bedeutung gewinnt, stellen Dehntrainings einen erfolgsversprechenden Ansatz dar. Allerdings sind die bislang überprüften Ansätze sehr zeitaufwendig, was zu einem erheblichen Verlust an Arbeitszeit führt. Ein Dehnprogramm mit geringem Zeitaufwand ist das gerätegestützte „five-Business“ Dehntraining, bei dem in fünf Übungen ganze Muskelketten intensiv gedehnt werden. Da das Gerät individuell einstellbar ist, ist die Trainingsintensität standardisiert und gleichzeitig individualisiert. Ziel dieser Studie war daher das five-Business“ Dehntraining auf seine Wirksamkeit hinsichtlich einer Verbesserung der Beweglichkeit, der Lebensqualität und von MSE zu evaluieren. Im Rahmen dieser Dissertation wurde in der ersten Publikation zunächst eine konkrete Methode erarbeitet, die anschließend als 12-wöchige Intervention bei Büroangestellten (Training zwei Mal wöchentlich für je 10 Minuten) umgesetzt wurde. Für die zweite Publikation wurden Veränderungen in der Beweglichkeit im Anschluss an die Intervention und deren Abhängigkeit von soziodemographischen und anthropometrischen Faktoren analysiert. Dazu wurden fünf Beweglichkeitstests verwendet: der Finger-Boden-Abstand und die Lateralflexion wurden mit einem Maßband evaluiert, während die Gelenkwinkel beim modifizierten Schultertest nach Janda, dem modifizierten Thomas Test und der Retroflexion des Rumpfes nach Janda mit einem digitalen Inklinometer gemessen wurden. Insgesamt nahmen 216 (79w; 137m) Probanden im Alter von 44,81 ± 10,55 Jahren freiwillig an der Studie teil. Die Probanden waren 1,76 ± 0,09 m groß und wogen 78,03 ± 15,11 kg. Die mittleren Unterschiede zeigten, dass die Probanden im Schultertest (rechts: 2,1 ± 7,7°, p = 0,001; links: 2,7 ± 10,11°, p = 0,001), in der nach Janda modifizierten Retroflexion des Rumpfes (5,4 ± 8,6°, p<0,001), im Finger-Boden-Abstand (-1,9 ± 4,0 cm, p<0,001) und in der Lateralflexion relativ zur Körpergröße (rechts: -0,004 ± 0,01, p = 0,002; links: -0,004 ± 0,01, p<0,001) Zuwächse im Bewegungsausmaß erzielten. Im Thomas Test zeigten die Probanden eine Abnahme der Flexibilität (rechts: -2,1 ± 4,5°, p<0,001; links: -1,2 ± 4,7°, p = 0,001). In allen Tests zeigten die Effektstärken geringe bis mittlere Effekte (d = 0,24 - 0,62). Probanden mit unterdurchschnittlicher Beweglichkeit im Prä-Test zeigten die höchsten Beweglichkeitszuwächse. Weder Alter, Körpergröße, Gewicht, Body-Mass-Index (BMI) noch Geschlecht hatten einen signifikanten Einfluss auf die Beweglichkeitsveränderungen. Insgesamt kann für das „five-Business“ Dehntraining resümiert werden, dass es effektiv zur Beweglichkeitssteigerung beiträgt. Der vergleichsweise geringe Zeitaufwand ist ausreichend, um insbesondere bei unterdurchschnittlicher Flexibilität zu einem Gewinn an Bewegungsreichweite beizutragen. Da weder soziodemographische noch anthropometrische Faktoren die Beweglichkeitsveränderungen signifikant beeinflussten, kann das „five-Business“ Dehntraining auch bei heterogen zusammengesetzten Kollektiven angewendet werden. Somit ist es als wirksame Dehnintervention als BGF Maßnahme für schreibtischgebundenen Büroangestellte einsetzbar.
Background: Dental professionals are subjected to higher risks for musculoskeletal disorders (MSDs) than other professional groups, especially the hand region. This study aims to investigate the prevalence of hand complaints among dentists (Ds) and dental assistants (DAs) and examines applied therapies. Methods: For this purpose, an online questionnaire analysed 389 Ds (240female/149male) and 406 DAs (401female/5male) working in Germany. The self-reported data of the two occupational groups were compared with regard to the topics examined. The questionnaire was based on the Nordic Questionnaire (self-reported lifetime, 12-month and 7-day MSDs prevalence of the hand, the conducted therapy and its success), additional occupational and sociodemographic questions as well as questions about specific medical conditions. Results: 30.8% of Ds affirmed MSDs in the hand at any time in their lives, 20.3% in the last twelve months and 9.5% in the last seven days. Among DAs, 42.6% reported a prevalence of MSDs in the hand at any time in their lives, 31.8% in the last 12 months and 15.3% in the last seven days. 37.5% of the Ds and 28.3% of the DAs stated that they had certain treatments. For both, Ds and DAs, physiotherapy was the most frequently chosen form of therapy. 89.7% of Ds and 63.3% of DAs who received therapy reported an improvement of MSDs. Conclusion: Although the prevalence of MSDs on the hand is higher among DAs than among Ds, the use of therapeutic options and the success of therapy is lower for DAs compared to Ds.
Traditional ergonomic risk assessment tools such as the Rapid Upper Limb Assessment (RULA) are often not sensitive enough to evaluate well-optimized work routines. An implementation of kinematic data captured by inertial sensors is applied to compare two work routines in dentistry. The surgical dental treatment was performed in two different conditions, which were recorded by means of inertial sensors (Xsens MVN Link). For this purpose, 15 (12 males/3 females) oral and maxillofacial surgeons took part in the study. Data were post processed with costume written MATLAB® routines, including a full implementation of RULA (slightly adjusted to dentistry). For an in-depth comparison, five newly introduced levels of complexity of the RULA analysis were applied, i.e., from lowest complexity to highest: (1) RULA score, (2) relative RULA score distribution, (3) RULA steps score, (4) relative RULA steps score occurrence, and (5) relative angle distribution. With increasing complexity, the number of variables times (the number of resolvable units per variable) increased. In our example, only significant differences between the treatment concepts were observed at levels that are more complex: the relative RULA step score occurrence and the relative angle distribution (level 4 + 5). With the presented approach, an objective and detailed ergonomic analysis is possible. The data-driven approach adds significant additional context to the RULA score evaluation. The presented method captures data, evaluates the full task cycle, and allows different levels of analysis. These points are a clear benefit to a standard, manual assessment of one main body position during a working task.
Triathletes often experience incoordination at the start of a transition run (TR); this is possibly reflected by altered joint kinematics. In this study, the first 20 steps of a run after a warm-up run (WR) and TR (following a 90 min cycling session) of 16 elite, male, long-distance triathletes (31.3 ± 5.4 years old) were compared. Measurements were executed on the competition course of the Ironman Frankfurt in Germany. Pacing and slipstream were provided by a cyclist in front of the runner. Kinematic data of the trunk and leg joints, step length, and step rate were obtained using the MVN Link inertial motion capture system by Xsens. Statistical parametric mapping was used to compare the active leg (AL) and passive leg (PL) phases of the WR and TR. In the TR, more spinal extension (~0.5–1°; p = 0.001) and rotation (~0.2–0.5°; p = 0.001–0.004), increases in hip flexion (~3°; ~65% AL−~55% PL; p = 0.001–0.004), internal hip rotation (~2.5°; AL + ~0–30% PL; p = 0.001–0.024), more knee adduction (~1°; ~80–95% AL; p = 0.001), and complex altered knee flexion patterns (~2–4°; AL + PL; p = 0.001–0.01) occurred. Complex kinematic differences between a WR and a TR were detected. This contributes to a better understanding of the incoordination in transition running.
Background; Musculoskeletal disorders (MSD) are a common health problem among dentists. Dental treatment is mainly performed in a sitting position. The aim of the study was to quantify the effect of different ergonomic chairs on the sitting position. In addition, it was tested if the sitting position of experienced workers is different from a non-dental group.
Methods; A total of 59 (28 m/31f) subjects, divided into two dentist groups according to their work experience (students and dentists (9 m/11f) < 10 years, dentists (9 m/10f) ≥ 10 years) and a control group (10 m/10f) were measured. A three-dimensional back scanner captured the bare back of all subjects sitting on six dentist’s chairs of different design. Initially, inter-group comparisons per chair, firstly in the habitual and secondly in the working postures, were carried out. Furthermore, inter-chair comparison was conducted for the habitual as well as for the working postures of all subjects and for each group. Finally, a comparison between the habitual sitting posture and the working posture for each respective chair (intra-chair comparison) was conducted (for all subjects and for each group). In addition, a subjective assessment of each chair was made.
For the statistical analysis, non-parametric tests were conducted and the level of significance was set at 5%.
Results: When comparing the three subject groups, all chairs caused a more pronounced spinal kyphosis in experienced dentists. In both conditions (habitual and working postures), a symmetrical sitting position was assumed on each chair.
The inter-chair comparisons showed no differences regarding the ergonomic design of the chairs. The significances found in the inter-chair comparisons were all within the measurementerror and could, therefore, be classified as clinically irrelevant.
The intra-chair comparison (habitual sitting position vs. working sitting position) illustrated position-related changes in the sagittal, but not in the transverse, plane. These changes were only position-related (forward leaned working posture) and were not influenced by the ergonomic sitting design of the respective chair. There are no differences between the groups in the subjective assessment of each chair.
Conclusions; Regardless of the group or the dental experience, the ergonomic design of the dentist’s chair had only a marginal influence on the upper body posture in both the habitual and working sitting postures. Consequently, the focus of the dentist’s chair, in order to minimize MSD, should concentrate on adopting a symmetrical sitting posture rather than on its ergonomic design.
Background: The aim of this pilot study was to analyze postures during the work of neurologists with respect to their occupational activities.
Methods: A total data material of 64.8 h (3885.74 min) of nine (three m/six f) neurologists (assistant physicians) was collected. Kinematic data were collected using the CUELA system (electro-goniometry). In addition, the occupational tasks performed on-site were subject to a detailed objective activity analysis. All activities were assigned to the categories "Office activities" (I), "Measures on patients" (II) and "Other activities" (III). The angle values of each body region (evaluation parameters) were evaluated according to ergonomic ISO standards.
Results: Only 3.4% of the working hours were spent with (II), while 50.8% of time was spent with (I) and 45.8% with (III). All tasks of category (II) revealed an increased ergonomic risk to the head, neck, trunk and back areas. During category (I) especially neck and back movements in the sagittal plane showed higher ergonomic risk levels.
Conclusion: Despite frequently performed awkward body positions in (II), the ergonomic risk is considered as rather low, since the percentage time share totaled only 3.4%. As a result, "Office activities" have been detected as high predictor to cause stress load on the musculoskeletal system in the daily work of neurologists.
Background: The aim of this study was to collect standard reference values of the weight and the maximum pressure distribution in healthy adults aged 18–65 years and to investigate the influence of constitutional parameters on it.
Methods: A total of 416 healthy subjects (208 male / 208 female) aged between 18 and 65 years (Ø 38.3 ± 14.1 years) participated in this study, conducted 2015–2019 in Heidelberg. The age-specific evaluation is based on 4 age groups (G1, 18–30 years; G2, 31–40 years; G3, 41–50 years; G4, 51–65 years). A pressure measuring plate FDM-S (Zebris/Isny/Germany) was used to collect body weight distribution and maximum pressure distribution of the right and left foot and left and right forefoot/rearfoot, respectively.
Results: Body weight distribution of the left (50.07%) and right (50.12%) foot was balanced. There was higher load on the rearfoot (left 54.14%; right 55.09%) than on the forefoot (left 45.49%; right 44.26%). The pressure in the rearfoot was higher than in the forefoot (rearfoot left 9.60 N/cm2, rearfoot right 9.51 N/cm2/forefoot left 8.23 N/cm2, forefoot right 8.59 N/cm2). With increasing age, the load in the left foot shifted from the rearfoot to the forefoot as well as the maximum pressure (p ≤ 0.02 and 0.03; poor effect size). With increasing BMI, the body weight shifted to the left and right rearfoot (p ≤ 0.001, poor effect size). As BMI increased, so did the maximum pressure in all areas (p ≤ 0.001 and 0.03, weak to moderate effect size). There were significant differences in weight and maximum pressure distribution in the forefoot and rearfoot in the different age groups, especially between younger (18–40 years) and older (41–65 years) subjects.
Discussion: Healthy individuals aged from 18 to 65 years were found to have a balanced weight distribution in an aspect ratio, with a 20% greater load of the rearfoot. Age and BMI were found to be influencing factors of the weight and maximum pressure distribution, especially between younger and elder subjects. The collected standard reference values allow comparisons with other studies and can serve as a guideline in clinical practice and scientific studies.
Background: In clinical practice range of motion (RoM) is usually assessed with low-cost devices such as a tape measure (TM) or a digital inclinometer (DI). However, the intra- and inter-rater reliability of typical RoM tests differ, which impairs the evaluation of therapy progress. More objective and reliable kinematic data can be obtained with the inertial motion capture system (IMC) by Xsens. The aim of this study was to obtain the intra- and inter-rater reliability of the TM, DI and IMC methods in five RoM tests: modified Thomas test (DI), shoulder test modified after Janda (DI), retroflexion of the trunk modified after Janda (DI), lateral inclination (TM) and fingertip-to-floor test (TM).
Methods: Two raters executed the RoM tests (TM or DI) in a randomized order on 22 healthy individuals while, simultaneously, the IMC data (Xsens MVN) was collected. After 15 warm-up repetitions, each rater recorded five measurements.
Findings: Intra-rater reliabilities were (almost) perfect for tests in all three devices (ICCs 0.886–0.996). Inter-rater reliability was substantial to (almost) perfect in the DI (ICCs 0.71–0.87) and the IMC methods (ICCs 0.61–0.993) and (almost) perfect in the TM methods (ICCs 0.923–0.961). The measurement error (ME) for the tests measured in degree (°) was 0.9–3.3° for the DI methods and 0.5–1.2° for the IMC approaches. In the tests measured in centimeters the ME was 0.5–1.3cm for the TM methods and 0.6–2.7cm for the IMC methods. Pearson correlations between the results of the DI or the TM respectively with the IMC results were significant in all tests except for the shoulder test on the right body side (r = 0.41–0.81).
Interpretation: Measurement repetitions of either one or multiple trained raters can be considered reliable in all three devices.
In the application of range of motion (ROM) tests there is little agreement on the number of repetitions to be measured and the number of preceding warm-up protocols. In stretch training a plateau in ROM gains can be seen after four to five repetitions. With increasing number of repetitions, the gain in ROM is reduced. This study examines the question of whether such an effect occurs in common ROM tests. Twenty-two healthy sport students (10 m/12 f.) with an average age of 25.3 ± 1.94 years (average height 174.1 ± 9.8 cm; weight 66.6 ± 11.3 kg and BMI 21.9 ± 2.0 kg/cm2) volunteered in this study. Each subject performed five ROM tests in a randomized order—measured either via a tape measure or a digital inclinometer: Tape measure was used to evaluate the Fingertip-to-Floor test (FtF) and the Lateral Inclination test (LI). Retroflexion of the trunk modified after Janda (RF), Thomas test (TT) and a Shoulder test modified after Janda (ST) were evaluated with a digital inclinometer. In order to show general acute effects within 20 repetitions we performed ANOVA/Friedman-test with multiple comparisons. A non-linear regression was then performed to identify a plateau formation. Significance level was set at 5%. In seven out of eight ROM tests (five tests in total with three tests measured both left and right sides) significant flexibility gains were observed (FtF: p < 0.001; LI-left/right: p < 0.001/0.001; RF: p = 0.009; ST-left/right: p < 0.001/p = 0.003; TT-left: p < 0.001). A non-linear regression with random effects was successfully applied on FtF, RF, LI-left/right, ST-left and TT-left and thus, indicate a gradual decline in the amount of gained ROM. An acute effect was observed in most ROM tests, which is characterized by a gradual decline of ROM gain. For those tests, we can state that the acute effect described in the stretching literature also applies to the performance of typical ROM tests. Since a non-linear behavior was shown, it is the decision of the practitioner to weigh up between measurement accuracy and expenditure. Researchers and practitioners should consider this when applying ROM assessments to healthy young adults.
Background: The aim of this pilot study was to analyze the work of neurologists regarding static posture (> 4 s) and to identify awkward postures. Methods: A total of 9 neurologists (assistant physicians; 3 male, 6 female) participated in this study. Kinematic data were collected using the computer-assisted acquisition and long-term analysis of musculoskeletal loads (CUELA; IFA, Sankt Augustin, Germany) system. Daily work (“office work,” “measures on patients,” and “other activities”) was analyzed with a computer-based task analysis. Results: During ”measures on patients,” more than 80% of the total percentage of non-neutral posture was assumed with a flexed position of the head and entire back, both during “blood collection” (4.7% of the time) and while “placing intravenous catheters” (8.3% of the time). In contrast, long static postures (> 30 s) in the head and neck area, including the thoracic spine, were adopted during “office work.” Despite the increased total percentage of non-neutral attitudes during measures on patients, the time share of 3.4% of the total working time is so small that the risk for developing musculoskeletal disorders (MSD) is negligible. In contrast, office work, which comprises 50.8% of the total working time and longer static postures, has a potential risk for the development of MSD. Conclusion: The present study is the first kinematic pilot analysis in the field of in-patient neurological assistants. Non-neutral as well as static postures in everyday work could be identified. Potential MSD can be reduced by optimizing the working height and by taking regular breaks to loosen the musculoskeletal system.
Musculoskeletal disorders of the trunk and neck are common among cleaners. Vacuum cleaning is a demanding activity. The aim of this study was to present the movement profile of the trunk and neck during habitual vacuuming. The data were collected from 31 subjects (21f./10 m) using a 3D motion analysis system (Xsens). 10 cycles were analysed in vacuuming PVC and carpet floors with 8 vacuum cleaners. The joint angles and velocities were represented statistically descriptive. When vacuuming, the trunk is held in a forwardly inclined position by a flexion in the hip and rotated from this position. In the joint angles and velocities of the spine, the rotation proved to be dominant. A relatively large amount of movement took place in the cervical spine and also in the lumbar spine. The shown movement profile is rather a comfort area of vacuuming which may serve as a reference for ergonomics in vacuuming.
Background: Vacuum cleaning, which is associated with musculoskeletal complaints, is frequently carried out in private households and by professional cleaners. The aim of this pilot study was to quantify the movements during habitual vacuuming and to characterize the movement profile with regard to its variability. Methods: The data were collected from 31 subjects (21 f/10 m) using a 3D motion analysis system (XSens). Eight vacuum cleaners were used to vacuum polyvinyl chloride (PVC) and carpet floors. In 15 joints of the right upper extremity, the trunk and the lower extremities, Principal Component Analysis was used to determine the predominantly varying joints during vacuuming. Results: The movements of the trunk and the lower extremities were relatively constant and, therefore, had less influence. The shoulder, elbow and wrist joints were identified as joints that can be decisive for the movement profile and that can be influenced. These joints were represented in the course of the vacuuming cycle by the mean movement with its standard deviation. Conclusion: In summary, the generalization of a movement profile is possible for the trunk and the lower extremities due to the relative homogeneity. In future it will be necessary to identify factors influencing variability in order to draw conclusions about movement ergonomics.
Background: Dentists are at a higher risk of suffering from musculoskeletal disorders (MSD) than the general population. However, the latest study investigating MSD in the dental profession in Germany was published about 20 years ago. Therefore, the aim of this study was to reveal the current prevalence of MSD in dentists and dental students in Germany. Methods: The final study size contained 450 (287 f/163 m) subjects of different areas of specialization. The age of the participants ranged from 23 to 75 years. The questionnaire consisted of a modified version of the Nordic Questionnaire, work-related questions from the latest questionnaire of German dentists, typical medical conditions and self-developed questions. Results: The overall prevalence showed that dentists suffered frequently from MSD (seven days: 65.6%, twelve months: 92%, lifetime: 95.8%). The most affected body regions included the neck (42.7%–70.9%–78.4%), shoulders (29.8%–55.6%–66.2%) and lower back (22.9%–45.8%–58.7%). Overall, female participants stated that they suffered from pain significantly more frequently, especially in the neck, shoulders and upper back. Conclusion: The prevalence of MSD among dentists, especially in the neck, shoulder and back area, was significantly higher than in the general population. In addition, women suffered more frequently from MSD than men in almost all body regions.
Hintergrund: Dehntrainings sind eine Maßnahme der betrieblichen Gesundheitsförderung (BGF) für Büroangestellte zur Prävention von muskuloskeletalen Erkrankungen (MSE). Sie können zu Beweglichkeitszuwächsen führen und auf psychischer Ebene entspannen. Ziel der Studie war es, ein standardisiertes und individualisiertes Dehntraining am Gerät, das „five-Business“, auf MSE, Lebensqualität und Beweglichkeit zu untersuchen. Dies ist eine Zusammenfassung der international publizierten Ergebnisse.
Methodik: In diese Untersuchung wurden 252 Proband(innen) eingeschlossen, 156 in die Interventionsgruppe (IG), 96 in die Kontrollgruppe (KG). Die IG absolvierte für 12 Wochen 22–24 Trainingseinheiten am „five-Business“, möglichst zweimal wöchentlich. Die Datenerhebung erfolgte mittels sportmotorischer bzw. Range-of-motion(ROM)-Tests, dem Nordic Questionnaire (NQ) und dem SF-36-Fragebogen in Form einer Prä-Post-Untersuchung.
Ergebnisse: Nach der Intervention gaben im NQ signifikant weniger Proband(innen) der IG Beschwerden im oberen Rücken (p < 0,001) im Vergleich zur KG an; keine signifikanten Unterschiede wurden bei Beschwerden im Nacken, Schultern, Hüfte und dem unteren Rücken gefunden. Der mit dem SF-36 erhobene allgemeine Gesundheitszustand und die gesundheitsbezogene Lebensqualität haben sich (nach subjektiven Angaben) signifikant verbessert (Summenscore IG: p = 0,005). In den ROM-Tests waren die Prä-Post-Differenzen bei IG-Proband(innen) in der Sagittalebene (Finger-Boden-Abstand und Retroflexion; p < 0,001) und im modifizierten Schultertest nach Janda auf der linken Seite (p = 0,003) signifikant größer.
Diskussion: Trotz des in Zeitdauer und Häufigkeit relativ geringen Trainingsaufwandes wurden sowohl auf körperlicher als auch auf psychischer Ebene relevante Verbesserungen erzielt, so dass das „five-Business“-Dehntraining als BGF-Maßnahme empfohlen werden kann.
Background: Dentists (Ds) and dental assistants (DAs) have a high lifetime prevalence of musculoskeletal disorders (MSDs). In this context, it is assumed that they have an increased intake of substances such as pain medication. Currently, there exist no data on the use of medication among Ds and DAs with MSDs in Germany. Methods: The online questionnaire (i.e., the Nordic Questionnaire) analysed the medical therapies used by 389 Ds (240 f/149 m) and 406 DAs (401 f/5 m) to treat their MSDs. Results: Ds (28.3–11.5%) and DAs (29.4–10.3%) with MSDs took medication depending on the affected body region. A trend between the Ds and DAs in the intake of drug therapy and the frequency was found for the neck region (Ds: 21.1%, DAs: 28.7%). A single medication was taken most frequently (Ds: 60.0–33.3%, DAs: 71.4–27.3%). The frequency of use varied greatly for both occupational groups depending on the region affected. Conclusion: Ds and DAs perceived the need for medical therapies because of their MSDs. Painkillers such as ibuprofen and systemic diclofenac were the medications most frequently taken by both occupational groups. The intake of pain killers, most notably for the neck, should prevent sick leave.
Background: dental professionals suffer frequently from musculoskeletal disorders (MSD). Dentists and dental assistants work closely with each other in a mutually dependent relationship. To date, MSD in dental assistants have only been marginally investigated and compared to their occurrence in dentists. Therefore, the aim of this study was to compare the prevalence of MSD between dentists and dental assistants by considering occupational factors, physical activity and gender. Methods: This was a cross-sectional observational study. A Germany-wide survey, using a modified version of the Nordic Questionnaire and work-related questions, was applied. In total, 2548 participants took part, of which 389 dentists (240 females and 149 males) and 322 dental assistants (320 females and 2 males) were included in the analysis. Data were collected between May 2018 and May 2019. Differences between the dentists and dental assistants were determined by using the Chi2 test for nominal and the Wilcoxon–Mann–Whitney U test for both ordinal and non-normally distributed metric data. Results: A greater number of dental assistants reported complaints than dentists in all queried body regions. Significant differences in the most affected body regions (neck, shoulders, wrist/hands, upper back, lower back and feet/ankles) were found for the lifetime prevalence, annual prevalence and weekly prevalence. Data from the occupational factors, physical activity and gender analyses revealed significant differences between dentists and dental assistants. Conclusions: Dental assistants appear to be particularly affected by MSD when compared to dentists. This circumstance can be explained only to a limited extent by differences in gender distribution and occupational habits between the occupations.
Background: In general, the prevalence of work-related musculoskeletal disorders (WMSD) in dentistry is high, and dental assistants (DA) are even more affected than dentists (D). Furthermore, differentiations between the fields of dental specialization (e.g., general dentistry, endodontology, oral and maxillofacial surgery, or orthodontics) are rare. Therefore, this study aims to investigate the ergonomic risk of the aforementioned four fields of dental specialization for D and DA on the one hand, and to compare the ergonomic risk of D and DA within each individual field of dental specialization. Methods: In total, 60 dentists (33 male/27 female) and 60 dental assistants (11 male/49 female) volunteered in this study. The sample was composed of 15 dentists and 15 dental assistants from each of the dental field, in order to represent the fields of dental specialization. In a laboratory setting, all tasks were recorded using an inertial motion capture system. The kinematic data were applied to an automated version of the Rapid Upper Limb Assessment (RULA). Results: The results revealed significantly reduced ergonomic risks in endodontology and orthodontics compared to oral and maxillofacial surgery and general dentistry in DAs, while orthodontics showed a significantly reduced ergonomic risk compared to general dentistry in Ds. Further differences between the fields of dental specialization were found in the right wrist, right lower arm, and left lower arm in DAs and in the neck, right wrist, right lower arm, and left wrist in Ds. The differences between Ds and DAs within a specialist discipline were rather small. Discussion: Independent of whether one works as a D or DA, the percentage of time spent working in higher risk scores is reduced in endodontologists, and especially in orthodontics, compared to general dentists or oral and maxillofacial surgeons. In order to counteract the development of WMSD, early intervention should be made. Consequently, ergonomic training or strength training is recommended.