The mental representation of the human gait in hip osteoarthrosis and total hip arthroplasty patients: A clinical cross-sectional study

Objective: To explore differences in gait-specific long-term memory structures and actual gait performance between patients with hip osteoarthrosis, patients seen six months after total hip arthroplasty and healthy controls to gain insights into the role of the gait-specific mental representation for rehabilitation. Design: Cross-sectional study Subjects: Twenty hip osteoarthrosis patients, 20 patients seen six months after total hip arthroplasty and 20 healthy controls Methods: Spatio-temporal (gait speed, step length) and temporophasic (stance time, swing time, single support time, total double support time) gait parameters, and gait variability were measured with an electronic walkway (OptoGait). The gait-specific mental representation was assessed using the structural dimensional analysis of mental representations (SDA-M). Results: Hip osteoarthrosis patients showed significantly longer stance and total double support times, shorter swing and single support times, and a decreased gait speed as compared with healthy controls (all P < 0.01). The differences in double support times were still evident in patients seen six months after total hip arthroplasty ( P < 0.01). The gait-specific mental representation differed between hip osteoarthrosis patients and healthy controls with regard to mid-stance and mid-swing phases; the mid-stance phase was still affected six months after total hip arthroplasty (both P < 0.05). Conclusion: Our data indicated that actual gait performance and gait-specific long-term memory structures differ between hip osteoarthrosis patients and healthy controls. Important, some of these disease-related changes were still evident in patients seen six months after total hip arthroplasty.