Benign joint hypermobility syndrome in soldiers; what is the effect of military training courses on associated joint instabilities?

Background: Hypermobile joints are joints with beyond normal range of motion and may be associated with joint derangements. This study aimed to evaluate the prevalence of benign joint hypermobility syndrome (BJHS) among soldiers and effect of training courses on related joint instabilities. Materials and Methods: In a prospective cohort study on 721 soldiers of Iran Army in Isfahan in 2013 the prevalence of joint hypermobility was obtained by using Beighton criteria. Soldiers divided in two groups of healthy and suffered based on their scores. The prevalence of ankle sprain, shoulder and temporomandibular joint (TMJ) dislocations identified before beginning service by history-taking and reviewing paraclinical documents. After 3 months of military training, a recent occurrence of mentioned diseases was revaluated in two groups. The collected data were analyzed using SPSS-20 software using Independent-T and Chi-square tests. Results: The frequency of BJHS before military training was 29.4%. After passing military training period, the incidence of ankle sprain was significantly higher in suffered group achieving the minimum Beighton score (BS) of 4 (4.3%, P = 0.03), 5 (5.5%, P = 0.005) and also 6 out of 9 (6.5%, P = 0.01). The incidence of TMJ dislocation was not significantly different based on a minimum score of 4, while it was higher in suffered group when considering the score of 5 (2.1%) and 6 (2.6%) for discrimination of two groups (P = 0.03). There was no significant difference between two groups in case of shoulder dislocation anyway. Conclusion: Military training can increase the incidence of ankle sprains and TMJ dislocations in hypermobility persons with higher BS in comparison with healthy people. Therefore, screening of joint hypermobility may be useful in identifying individuals at increased risk for joint instabilities.