Who is going to be diagnosed with musculoskeletal problem in adulthood? Take a look at high school grades in physical education

Abstract

In this issue of Pain, Simon Timpka and colleagues [5] from the Lund University Hospital in Sweden report the findings that physical education may help to identify a group at risk for musculoskeletal complaints later in adulthood. Using a longitudinal approach, they found that those adolescent girls with the lowest grade in physical education instruction were significantly more likely to be diagnosed with musculoskeletal conditions compared to those with higher grades. Strengths of their study include its longitudinal design, the fact that grade in physical education was not self-reported and that the outcome measurements (i.e. «Diseases of the musculoskeletal system and connective tissue») was derived from medical diagnoses. Finally, this paper also reinforces that physical education teachers may be useful in the screening of various health problems, such as obesity [4] and motor deficits [3], and perhaps also for screening problems that may take longer to develop. As suggested by the authors, because the great majority of children has to attend school, the question merits further research. Results from physical education courses could provide a powerful screening of various problems, especially when simple field tests or assessment tools are available. The capacity of physical education grades to predict future MS pain is most certainly dependent on the evaluation criterion used by the physical educators and this undoubtedly is different today than in the 1970’s. As shown by Barnekow-Bergkvist et al. [1], a high score in lifting strength at 16 years of age, decreased the risk of low back pain in adulthood in females. In males, a high score (number of repetitions) in the bench press (number of lifts) at the same age was associated with a decreased likelihood for future neck-shoulder pain. Recent curriculum changes in physical education have focused on obesity prevention and promotion of healthy lifestyle. Older curricula (e.g. in the 1970’s) often focused more on motor skills and sports-related performance elements. Clearly, if grading criteria were to be changed, then grades in physical education may no longer serve as useful or significant a predictor of musculoskeletal complaints, as the criteria commonly used in years ago. This will certainly be the case if fitness tests that reliably predict future musculoskeletal problems were to be removed from standard curricula. Therefore, the effect of evaluation criterion on the predictive power of physical education grades for musculoskeletal complaints warrants future research. An important difficulty in such studies is to control for the selection effect, namely those children with better physical capacities could be those with better grades in physical education and may be the same individuals who remain healthy as adults. The authors eliminated some important potential confounders, such as illness at baseline measurement. One confounder that was not controlled for, however, was the physical activity level outside school. The magnitude of that activity may not only influence physical education grades while in school but also on physical activity later in life. For example, Glenmark et al. [2] showed that physical activity and grades in physical education at adolescence could account for 82% of the physical activity level in adulthood for women, but only 47% for males. Another study also measured the relationship between school physical education and musculoskeletal health later in life [6]. The authors of that study found that a daily physical education program during primary school (7–12 years old) was associated with a lower rate (RR = 0.58) of lower back problems in 35 yearold females than their counterpart in the control groups that received only the standard 40 min per week ‘‘Provincial” physical education program used at the time. Interestingly, both Timpka and co-authors [5] and Glenmark et al. [2] suggested that adult females may have greater musculoskeletal benefits associated with a higher level of physical activity or with higher grades in physical education during adolescence. Unquestionably, the suggestion of Timpka et al. [5] to study the gender effects of physical education and physical activity on musculoskeletal health is justified as is their recommendation that a bio-psycho-social approach should be adopted to study this question.