Gait during hydrokinesitherapy following total hip arthroplasty

Purpose. To obtain gait parameters during hydrotherapy (HT) in patients who were referred for rehabilitation after total hip arthroprostheses. Method. The study had a cohort prospective design. Patients who underwent primary total hip arthroplasty (THA) followed a HT rehabilitation program. Twenty-one consecutive patients were enrolled. Five of them dropped out for various reasons, independently of HT. Therefore 16 patients could be evaluated ( 5 men and 11 women). Sixteen age-matched healthy volunteers were the control subjects. Nine patients had a right THA and 7 a left THA. On average HT duration was 15.7 days (SD 3.8). Results. The patients presented with a mean speed of 749 meters per hour ( SD 146) at the baseline. At the last session the mean speed was 1175 meters per hour ( SD 396). The mean stance duration was 1.59 s ( SD 0.28) on the operated side and 1.67 ( SD 0.27) on the non-operated side. By contrast, the mean swing duration was 1.02 s ( SD 0.20) on the operated side and 0.95 s ( SD 0.16) on the non-operated side. The differences in balance were statistically significant. The step duration was the same on both sides. At the beginning of HT the stance/swing ratio was 1.62 ( SD 0.40) on the operated side, whereas it was 1.74 ( SD 0.42) on the non-operated side. In the controls the ratio was 1.45. During HT both values fluctuated but the trend was toward a better coherence over time. At the beginning the mean stride length was 0.484 meters ( SD 0.116) and the value became 0.628 ( SD 0.131) after 15 training sessions. At the individual level, recovery occurred in a non-linear fashion, but the mean regression line had a coefficient of 27.1 and the intercept was at 560.3. Conclusions. The study design permits accurate definition of stride parameters during rehabilitation which allows optimization of the programme. Increase in speed and regain of balance are monitored on a daily basis and they appear as the targets of a HT programme.