Open Access Research

Pre-operative ambulatory measurement of asymmetric lower limb loading during walking in total hip arthroplasty patients

Alicia Martínez-Ramírez12*, Dirk Weenk2, Pablo Lecumberri1, Nico Verdonschot23, Dean Pakvis4 and Peter H Veltink2

Author Affiliations

1 Mathematics Department, Public University of Navarra, Pamplona, Spain

2 Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, P.O. Box 217, Enschede 7500 AE, The Netherlands

3 Department of Orthopaedics 800, Radboud University, Nijmegen Medical Centre, Postbox 9101, Nijmegen 6500 HB, Netherlands

4 Department of Orthopedic Surgery, Medisch Spectrum Twente, PO Box 50000, Enschede 7500 KA, The Netherlands

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Journal of NeuroEngineering and Rehabilitation 2013, 10:41  doi:10.1186/1743-0003-10-41

Published: 20 April 2013

Abstract

Background

Total hip arthroplasty is a successful surgical procedure to treat hip osteoarthritis. Clinicians use different questionnaires to assess the patient’s pain and functional capacity. Furthermore, they assess the quality of gait in a very global way.

This clinical evaluation usually shows significant improvement after total hip arthroplasty, however, does not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which can currently only be obtained in a gait laboratory. Instrumented force shoes can quantify gait velocity, ground reaction forces and the gait pattern easily in an outpatient setting.

The main goal of this study was to investigate how mobility characteristics during walking, relate to gait velocity and questionnaire outcomes of patients with hip osteoarthritis in an outpatient setting.

Methods

22 patients with primary osteoarthritis of the hip selected for a total hip arthroplasty participated in this study. For each patient the Harris Hip Score, the Traditional Western Ontario and the McMaster Universities osteoarthritis index were administered. Subsequently, the patients were instructed to walk through the corridor while wearing instrumented shoes. The gait velocity estimated with the instrumented force shoes was validated measuring the time required to walk a distance of 10 m using a stopwatch and a measuring tape as a reference system. A regression analysis between spatial, temporal, ground reaction force parameters, including asymmetry, and the gait velocity and the questionnaires outcomes was performed.

Results

The velocity estimated with the instrumented shoes did not differ significantly from the velocity measured independently. Although gait parameters correlated significantly with velocity, symmetry index parameters were not correlated with velocity. These symmetry index parameters show significant inter-limb asymmetry during walking. No correlation was found between any of the variables studied and questionnaires outcomes.

Conclusion

Inter-limb asymmetry can be evaluated with the instrumented shoes supplying important additional information about the individual gait pattern, which is not represented by gait velocity and questionnaires usually used. Therefore, this new ambulatory measurement system is able to provide complementary information to gait velocity and questionnaires outcomes to assess the functional capacity of patients with hip osteoarthritis.

Keywords:
Instrumented force shoes; Gait parameters; Hip osteoarthritis; Total hip replacement; Vertical ground reaction forces