[Gait pattern of patients with hip arthritis]

Automatic recording of the kinematic and kinetic gait pattern has so far not been commonly used in the diagnosis of problems affecting the human loco motor apparatus. In recent decades gait analysis has increasingly been applied in the development of endoprostheses and sports shoes and in rehabilitation, especially of patients with neurological diseases. When a gait laboratory is set up, this demands interdisciplinary cooperation, biomechanical knowledge in physicians and (physio-)therapists, and elaboration of treatment plans allowing direct therapeutic exploitation of the gait data. There are determinant factors in gait pattern, which does not vary qualitatively in the sagittal plane (flexion/extension) with sex and age until the age of 70 years. Quantitatively there is a great deal of individual variation, and the diagnosis of a pathologic function in a particular patient can be difficult. A normal reference population was used to determine the gait pattern characteristic for 32 patients with osteoarthritis of the hip on one or on both sides, and the possible significance of the results for physical and surgical therapy is discussed. The main characteristic of this gait pattern ist the limitation of hip extension before toe-off in the late stance phase. One-third of the patients answer compensate with this increased hip flexion at heel strike, which in turn leads to an increased load on the (more severely) affected side. In consequence, the increased load might lead to progression of the osteoarthritis. In the development of endoprostheses it should be borne in mind that the design may influence the gait pattern, producing overloading of the extremity and perhaps reducing the life of the prosthesis.