Work-related musculoskeletal disorders among physiotherapists and physiotherapy students in Croatia and their association with physical fitness

Musculoskeletal disorders (MSDs), cumulative damage/ dysfunction of the musculoskeletal system caused by prolonged and repeated exposure to high- or low-intensity loads or as a result of acute trauma (1), are the most common cause of severe long-term pain/discomfort causing physical disability. Work-related MSDs (WMSDs) are MSDs in which the work environment and work contribute significantly to the condition and/or the condition worsens/ persists longer due to work conditions (2). They are the most common work-related health problem in the European Union (EU), with an average prevalence of about 60% (3, 4), ranging from 40-79% in the Member States in 2015 (3). All occupations can be affected, but human health and social work occupations more so than others (3).

In physiotherapists, the WMSDs prevalence is higher than average. The 12-month prevalence is estimated at 58-91% (5, 6, 7). Moreover, Glover et al. determined that 42% of musculoskeletal symptoms persisted for >3 days within the past year (5). The leading cause of WMSDs among physiotherapists is the performance of repetitive movements or intense physical demands (lifting heavy patients, manual handling, patient handling, awkward positioning, prolonged constrained postures) (6, 7, 8, 9). The most frequently affected areas are the lower back (6, 7, 8, 9, 10, 11, 12, 13), neck and upper back (8, 9), and thumb (6). To carry out the physically demanding work of a physiotherapist, it is necessary to ensure satisfactory physical fitness (PF).

PF is defined as the capacity for physical activity, which is defined as any bodily movement produced by skeletal muscles that results in energy expenditure. It consists of five components: body composition, cardiorespiratory and muscle endurance, muscle strength and flexibility (14). The level of PF is partially genetically predetermined but is influenced by external factors, such as exercise. Although good PF is considered a protective factor for the occurrence of MSDs, research to date has not been able to show this statistically (15, 16, 17).

The latest available data show that the prevalence of WMSDs in Croatia is slightly higher than the average in the EU (2015: 62%) (4). Data on PF and the prevalence of WMSDs among physiotherapists/physiotherapy students in Croatia are very limited. Only recently, studies addressing this topic have emerged (18, 19). Sklempe Kokic et al. (2019) for example, estimated the last 12-months prevalence of MSDs among physiotherapy students at about 80% (18).

Aiming to provide evidence for the development of evidence-based health promotion programmes for maintaining adequate PF in physiotherapists to decrease their WMSDs starting in the years of studying, the objectives of this study were a) to assess the differences in self-rated WMSDs and PF components between physiotherapists and students of physiotherapy and b) to assess the association between WMSDs and PF components.

The study showed two unexpected results, both regarding physiotherapy students. First, they had pain in the lower back and knees essentially as often as physiotherapists; second, two thirds of them had poor/very poor flexibility. Regarding the prevalence, the results could only be compared with the results of the study of Glover et al. (5) in which the question about experiencing WMSDs was most similar to the question in our study (symptoms that lasted >3 days); the observed prevalence in their study was 42%. As the composition of the studied group was to a certain extent also similar (94% of the studied group consisted of physiotherapists and physiotherapy students, and 6% physiotherapy assistants), we can conclude that the problem in Croatia seems to be slightly greater than in the UK. Comparison with other studies was not possible due to differences in the question about WMSDs, which in our study focused only on WMSDs prevalence of longer duration (>3 days) in the previous 12 months, while other studies were focused on the previous 12-month prevalence of WMSDs without specifying the duration (7, 18), or lifetime prevalence of WMSDs (6, 9). A comparison regarding the location of the pain was less problematic. Studies in this area have shown that our results are very similar: the most common pain locations were the lower back, neck, and shoulders (5, 35, 36). For students, the location could also be compared to a recent study conducted in Croatia (18). The results were very similar: the highest prevalence was observed, as in our study, in the lower back, neck, and upper back. As expected, the prevalence of WMSDs in our study was higher in physiotherapists in comparison to students in general, as well as in many individual locations. Although the prevalence of low back pain between students and physiotherapists has not been significant, it is important to note that this finding in students is worrying, which may be related to an increased sedentary lifestyle, and it should be investigated further. Similar, though less pronounced, is the problem in two other locations – knees and upper back. The latter was revealed only by multivariate analysis.

The body composition of physiotherapy students was within the normal range, similarly to other recently published studies (15, 28, 36, 37, 38), and was statistically significantly better than in physiotherapists, although it was still within acceptable limits, which is consistent with the study of Ramanadi et al. (16). Cardiorespiratory endurance was also statistically significantly better in students than in physiotherapists, for whom it was surprisingly poor. The situation was similar in muscular endurance, which was scored as excellent for students. The results were similar to those of Juhkam et al. (37). The first PF component of concern in students was muscular strength. The isometric handgrip strength is one of the important components of PF, indicating the strength of the upper limb and, indirectly, the whole body (39). We expected students to do better than physiotherapists, but the two groups were quite similar. A similar result was shown by Juhkam et al. (37). It would make sense to direct students to a physical activity requiring more involvement of the upper limbs and handgrip. Unexpected was the result of the flexibility test in which as many as two thirds of students demonstrated poor or even very poor flexibility. Consequently, students should be directed to perform activities that will increase the extensibility of the dorsal muscle chain of the boot and hip (40). Again, a similar result was observed in another study (41).

There are few published studies on the relationship between WMSDs and PF, and comparison with other results is difficult. The only similar study by Mirza and collaborators showed very similar results - the association between PF and WMSDs could not be confirmed (15). A statistically significant positive association was observed only between knee pain and poor cardiorespiratory endurance, while other statistically significant results were debatable (in the shoulder, the elbow/forearm, and the hip/thigh pains). Poor cardiorespiratory endurance and poor flexibility in our study seemed to be protective factors for pain as a contradictory result; however, as previously stated, the available literature thus far has not shown a statistical relationship between PF and WMSDs.

The study has some limitations. First, the observed group was too small, which, given the low frequency of some observed WMSDs, did not allow for more in-depth analyses, although the size of the participants was estimated in accordance with the theory and was expected to be large enough (42). However, we still obtained some very important results. Representativeness was also not an issue, as all identified physiotherapists at the time of the study and all students in the academic year were invited, and the response rate was on average more than 90%. Next, there is a time mismatch of the variables in the multivariate models. However, as in similar studies, we asked about the symptoms of WMSDs in the previous 12 months, and this could be at any time during the past 12 months and quite distant in time, while in a cross-sectional design the PF measurements could only be performed at the time of the study. Next, one could argue that the original general NMQ, whose reliability proved to be moderate to high in the majority of questions with kappa coefficients above 0.50 (43), was not used. However, some parts have been used, although slightly modified or supplemented. First was the question on the occurrence of troubles at any time during the last 12 months, which was modified in the sense that the focus in our study was only on troubles lasting >3 days occurring during physiotherapeutic activities. All locations of troubles listed in the original NMQ were also used (in all yes or no regardless of the body side), while the thumb location was added. Other parts of the original general NMQ were omitted. Next, one could also argue that the Physical Workload Questionnaire was not used in judging workplace workload. Finally, the applied fitness tests have rather low sensitivity. For each component of PF, it is possible to use several different tests, focusing more on the examination of the upper or lower part of the body. However, we believe that the application of other tests would not significantly contribute to a change in the obtained results of measuring the parameters of PF.

Nevertheless, the study has some important strengths. First, this is the first study showing the level of PF and the problem of WMSDs among physiotherapists in Croatia in relation to physiotherapy students. Next, one very important strength is that it is a study on a population with very high responsiveness. This allows a reliable estimate of prevalence. Finally, the results could be useful in other social environments as well, especially in those where the transition took place in a similar way and, consequently, the values of the younger generations of the population are subject to similar changes in values.

The results provide very important implications in terms of where to direct efforts to prepare future physiotherapists physically for their future profession. The educational institution should be actively involved, as should the physiotherapists from whom students receive practical training. It would make sense, for example, to direct students to organised physical exercise, which would be useful not only during their studies, but could also be performed in late adulthood to prevent frailty (44). An appropriate exercise, which is also popular among young people, could be yoga (45).

In the continuation of research in this field, it would first be necessary to increase the sample size, while choosing fitness tests appropriate for the individual location of WMSDs due to greater sensitivity. In addition, it would be sensible to construct a questionnaire that puts the phenomena in which we observed the relationship in the right place in terms of chronological order and simultaneity.

The study showed two important unfavourable results. The first is that physiotherapy students have pain in the lower back even more often than their older senior colleagues, and the second is that an extremely high percentage of physiotherapy students have poor flexibility. Both results are issues of great concern and indicate where action is needed – in promiting physical activity for the preservation and improvement of the health of physiotherapy students. UAHSZ should be more involved in introducing them to this problem. This role should be played by staff involved in clinical practice, who by their example, and work activities, can improve their attitude to PF and physical activity.