Biofeedback training for partial weight bearing in patients after total hip arthroplasty

OBJECTIVE: To evaluate a new biofeedback training method based on visual delivery of information in patients after total hip arthroplasty (THA). DESIGN: Intervention study with prepost design. SETTING: Hospitalized care in a university referral center. PARTICIPANTS: Patients (N=11) (age 56.1+/-9.0 y) shortly after THA. INTERVENTION: A mobile system has been used for biofeedback training with the predefined partial weight bearing (PWB) threshold of 20 kg. After the learning period, 4 retention tests, consisting of 3 successive walking cycles without feedback, were recorded for each patient: (1) acquisition test, (2) early retention test (after 30 min), (3) the day after, and (4) after 2 days. MAIN OUTCOME MEASURE: The pressure error and the maximum pressure force at each step before and after biofeedback training. RESULTS: A significant difference of pressure errors between the beginning and the end of the learning period has been measured (42.5+/-22.5 N vs 3.7+/-11.4N, P<.001). However, there was no difference between the beginning of the learning period and different retention tests (after 30 minutes, after 1 day, after 2 days). In terms of maximal pressure force, there was a difference between the beginning and the end of learning (251 N vs 195 N, P<.05). The retention tests did not show significant differences compared with the baseline values. CONCLUSIONS: THA patients were able to use the defined PWB during a short period of time and shortly after stopping the training; both the pressure errors and the maximal pressure force attended the values before training. These results confirm the difficulties to achieve PWB in patients after THA