Ambulatory efficiency in persons with acquired brain injury after a rehabilitation intervention

Objective: The purpose was to assess changes in cardiorespiratory responses to treadmill ambulation in a sample of patients with acquired brain injury. Research design: A repeated measures, pre-test post-test design examined differences between sub-maximal and peak responses at admission and discharge. Methods and procedures: Forty individuals (29 male, 11 female) were studied. Subjects performed an ambulatory treadmill test during which heart rate (EKG) and oxygen consumption (VO₂) were monitored continuously. Total ambulation time (TAT) was also recorded. Results: TAT increased from 10.3 (SD 3.1) minutes to 13.6 (SD 3.5) minutes (p < 0.01). Peak HR did not change (168 (SD 20) bpm vs. 167 (SD 21 bpm)) nor did peak VO₂ (23.5 (SD 6.6) ml/min/kg vs. 24.3 (SD 6.4) ml/min/kg; p = 0.09). However, both sub-maximal HR and VO₂ decreased (p < 0.05) between 2-12 minutes when most subjects were still capable of ambulating. Conclusions: The results suggest an improvement in both aerobic capacity and movement efficiency. Further controlled studies will be necessary to distinguish between cardiorespiratory and neuromuscular adaptations. The changes observed should allow for greater community participation and functional independence after discharge.