Predictive Factors of Cessation of Ambulation in Patients with Duchenne Muscular Dystrophy

Objectives: To identify baseline patient and treatment characteristics that can predict wheelchair dependency within 2 yr.

Design: This prospective cohort study included 44 subjects who met study inclusion criteria. The same investigator examined them at 6-mo intervals. Ambulatory status, anthropometric data, muscle strength, range of motion of weight bearing joints, scoliosis, WeeFIM instrument, Functional Status II revised, and use of standing and walking aids. Cox proportional hazards regression analysis and the stepwise technique were used to search for prognostic factors of wheelchair dependency within 2 yr.

Results: Children with impaired hip extension and ankle dorsiflexion strength are 11.5 (95% confidence interval, 3.2-40.5) and 3.7 (95% confidence interval, 1.4-9.7) times, respectively, more likely to stop ambulating within 2 yr.

Conclusions: This study confirms that strength loss, specifically in hip extension and ankle dorsiflexion, are the primary predictors of loss of ambulation in Duchenne muscular dystrophy. Further research is needed for medical interventions that can improve hip extension or ankle dorsiflexion and actually can improve ambulation.