Background A more than average range of joint motion may present a potential athletic benefit for certain sports and is often seen as a prerequisite in order to reach the level of a professional athlete. Other individuals with generalized joint hypermobility (GHM) may experience a wide variety of health problems that result in disability. In the last decade several mechanisms for the onset of musculoskeletal complaints in individuals with GHM have been proposed, ranging from deconditioning to maladaptive coping, however to date no causal factor has been identified. Symptomatic and nonsymptomatic forms of GHM differ on physical functioning but share one commonality: the presence of GHM.

Objectives To determine the consequences of GHM on physical functioning in young adults with non-symptomatic GHM.

Methods A total of 234 participants were included (mean age: 20, range: 17-24). Subjects were excluded when symptomatic GHM was present (Brighton criteria), or when any other type of condition was present that could influence physical functioning. Data on age, gender, BMI, joint mobility (Beighton score), muscle strength, physical functioning (single leg hop test and physical activity level) were collected. Linear regression analyses were performed in which physical functioning was used as the dependent variable and joint mobility was used as the independent variable corrected for age, gender and BMI.

Results A negative, significant association was found between total muscle strength and joint mobility (B(SE): -30.1 (8.8), p=0.00). Indicating that increases in joint mobility are associated with decreases in muscle strength. No effects of joint (hyper) mobility were found on both functional jumping distance and total physical activity level. A specific activity pattern was present in hypermobile individuals, indicating a preference for non weight bearing activities with low peak joint forces.

Conclusions We conclude that nonsymptomatic GHM results in decreased muscle strength without the presence of musculoskeletal complaints. Although loss of muscle strength was hypothesized to be associated with symptomatic forms of GHM, this raises the question whether the elasticity of connective tissue plays a more predominate role in the loss of muscle strength rather than being the result of deconditioning. Although hypermobile individuals have lower muscle strength, especially in the ankle joints, and more flexible joints which could be more instable, jumping distance and PAL remained unaffected. Still when regarding PAL a specific pattern was present indicating the preference for non weight bearing activities which require low joint forces. In order to cope with increased laxity which directly effects muscle strength, healthy individuals with GHM possibly employ adaptive strategies in order to enable normal physical functioning.

1. Grahame R. Hypermobility: an important but often neglected area within rheumatology. Nat Clin Pract Rheumatol 2008;4(10):522-4.

2. Day H, Koutedakis Y, Wyon MA. Hypermobility and dance: A review. Int J Sports Med 2011;32:485-9.

3. Russek LN. Examination and treatment of a patient with hypermobility syndrome. Phys Ther 2000;80:386-98

Disclosure of Interest None Declared