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Al-sirri N.1, Cramp M.1, Barnett S.1, Palmer S.1
1University of the West of England, Department of Allied Health Professions, Bristol, United Kingdom
Background: Joint hypermobility syndrome (JHS) is a heritable connective tissue disorder associated with symptomatic multiple joint laxity with a 30% prevalence found in one musculoskeletal triage service in the UK. Gait is essential for functional capacity, general health, and participation. Only two studies have explored gait in adults with JHS, although their external validity has been risked by small sample sizes. The current study assessed gait and challenged the lower limb joints by introducing an advanced task, vertical jump, to make it difficult to employ compensatory strategies and identify any underlying problems.
Purpose: The aim was to explore the impact of JHS on the lower limb joint kinematics.
Methods: The JHS group included 27 women and 2 men (mean (SD) age 37.57 (13.77) years) and the control group included 28 women and 2 men (39.27 (12.59) years). The Brighton criteria were used to confirm JHS. Patients were recruited from the Hypermobility Syndromes Association and two secondary care hospitals in South West England. The research was approved by the East Midlands Research Ethics Committee (14/EM/1008). Joint kinematics were assessed using the Qualisys motion capture system. Participants were asked to walk at their normal walking speed for ten times, and jump to their comfortable height for three times. Independent sample t-tests and Mann-Whitney U tests were used to identify differences between groups. A difference ≥ 20 between the two groups in kinematics was considered as a trend, having previously been established as the magnitude of intra-session variability.
Results: During the swing phase of walking, the JHS group showed significantly lower mean (SD) pelvic obliquity [3.62 (2.28)0] and right hip abduction [-2.91 (3.49)0] when compared to the control group [4.88 (2.13)0 and -4.73 (2.71)0 respectively] (p = 0.03 and 0.02). Increased left hip adduction at initial contact was identified in the JHS group [3.10 (2.97)0] when compared to the control group [1.37 (3.36)0] (p = 0.04). Trends toward kinematic reductions were found in the JHS group during the stance phase in pelvic rotation, right hip flexion and bilateral hip extension. During the swing phase, trends toward kinematic reductions were found in the JHS group in left hip internal rotation and abduction, right hip extension and left knee flexion. Regarding the vertical jump test, no statistically significant differences were found. Trends toward kinematic reductions (range of motion reductions) were found in the JHS group in hip flexion and knee flexion during the compression phase, and in hip extension, knee extension and external rotation during the push phase.
Conclusion(s): The JHS group walked and jumped with a kinematic stiffness pattern and their joint hypermobility was not evident, which could be a pattern to avoid pain and improve balance. Future research is needed to determine the benefit of these strategies if they persist in the long term, and their effect on activity and participation.
Implications: People with JHS compensate by stiffening their lower limb joints during walking and jumping. Future research is required to understand how this impacts on activity and participation and if movement reeducation can improve kinematics.
Funding acknowledgements: The research is sponsored by the University of the West of England, Bristol, and funded by Kuwait Government.
Topic: Rheumatology
Ethics approval: The research was approved by the East Midlands Research Ethics Committee (reference number 14/EM/1008).
All authors, affiliations and abstracts have been published as submitted.
