Singer BJ, Dunne J,. Singer KP, Jegasothy GM, Allison GT (2004) Ankle contracture following moderate to severe acquired brain injury: incidence and physical therapy management. Disability Rehabilitation. 26: 335-345

Abstract

Secondary musculoskeletal impairments, such as reduced dorsiflexion range, are common following acquired brain injury. The purpose of this study was to examine the incidence and physical therapy management of ankle contracture in a cohort of patients undergoing inpatient rehabilitation following moderate to severe acquired brain injury.

Methods

Age, gender, diagnosis, severity of injury, maximal passive ankle dorsiflexion with the knee extended and plantarflexor/invertor muscle tone were collected for 105 patients. Subjects were allocated retrospectively into one of four 'ankle outcome'categories according to ankle range and response to physical therapy intervention. The association between the type and severity of abnormal muscle activity and ankle outcome category was examined.

Results

No ankle abnormalities were identified in 65 patients (62%) (category 1). In twenty-three patients (22%) reduced dorsiflexion range resolved with standard physical therapy treatment (category 2). Seventeen patients (16%) had contracture which persisted or worsened despite standard physical therapy treatment. Ten of these underwent specific treatment including serial casting and, in some cases, adjunctive injection of botulinum toxin type A (category 3). Invasive management was not considered an appropriate priority in seven subjects due to the severity of their overall disability (category 4). Dystonic muscle overactivity was strongly associated with contracture. No subject in categories 3 or 4 presented with normal tone or spasticity in the affected limb. Two case studies illustrate the interaction between muscle overactivity and rheologic changes within the musculo-tendinous unit.

Conclusion

The incidence of ankle contracture in this cohort was much lower than previously reported. Effective treatment for this complex impairment depends on accurate evaluation and appropriate remediation. Peripheral manifestations of upper motor neurone damage can be influenced by rheologic properties such as muscle length and stiffness and, conversely, chronic muscle overactivity can lead to adaptive shortening and altered joint mechanics.