Objectives

To investigate whether the rate of change of muscle strength in people with joint hypermobility syndrome (JHS) who have anterior knee pain (AKP) differs when compared to 2 control groups who have AKP and to evaluate the relationship between strength and pain as well as the effect of strength upon activity and knee function.
Design

A cohort study, with 3 groups: JHS with AKP, generalized joint hypermobility with AKP (GJH), and normal flexibility with AKP (control group [CG]). Follow-up appointments were performed every 2 weeks for 16 weeks.
Setting

The physiotherapy outpatient department within a London (United Kingdom) hospital.
Participants

A total of 102 people, aged between 18 and 55 years, were recruited between July 2014 and March 2016; 47 JHS, 29 GJH, and 26 CG (N=102). After 16 weeks, 31, 20, and 21 participants completed the study, respectively. Participants were recruited from support groups, a London hospital group and university, local sports centers, and clubs.
Interventions

Individualized leg exercises for 16 weeks.
Main Outcome Measure

Muscle torque generated from the lower limb, every 2 weeks for 16 weeks.
Results

There was no difference in the rate of change of concentric muscle strength between the JHS group and the CG or GJH group (P>.88 and P>.97). There was no difference in the rate of change of eccentric muscle strength between the JHS group and the CG or GJH group (P>.60 and P>.94). However, people with JHS were significantly weaker than the other 2 groups, taking 3 to 4 months to reach the baseline strength of the GJH group.
Conclusion

People with JHS can strengthen at the same rate as other people in pain.