TEPStabil - Muscle Function and Dynamic and Postural Stability in Patients Receiving Hip or Knee Arthroplasty

Postural stability is defined as the ability to maintain the body's centre of gravity within the limits of stability as determined by the base of support. It is further divided in static and dynamic stability involving the ability of maintaining a base of support while standing or completing a functional Task. The importance of postural stability is accepted as a factor predicting falls and affecting the ability to perform activities of daily living. Despite of reported strength deficits and the importance of balance, to date the potential contribution of strength deficits in patients before and after Total Hip Arthroplasty (THA) or Total Knee Arthroplasty (TKA) to compromised balance ability is unknown. Furthermore, the role of preoperative muscle function on functional outcome of THA and TKA is poorly understood. A correlation between compromised preoperative muscular function and postoperative outcome would suggest that preoperative physical therapy may be critical for preserving the muscular status and may help explain reported poorer outcome after late treatment when muscular function has already deteriorated. The project includes two studies differing in design and primary and secondary objectives but with overlapping patient populations. Study 1 will include all five groups, and there is only one visit by the participant (visit A). Study 2 will include only patients from groups 3 and 4. Three assessments will be performed: preoperatively (visit 1), 6 weeks postoperatively (visit 2) and 1 year postoperative (visit 3). Visit 1 will be identical to visit A in study 1 in these two patient groups.