Abstract

Question: Is 50% Partial Weight Bearing Really 50%.

Design: Twelve volunteers participated in this prospective, case-control study utilising a portable limb load monitor (NCOunters VIC) to measure the PWB load exerted. The device was attached and calibrated to the individual’s body weight. 50%, 25% and 5% PWB were tested with crutches and a four wheel frame (4WF). The tests were repeated following physiotherapy education. Participants: 12 healthy volunteers.

Intervention: gait aids- crutches, 4WF. Results measured pre- and post- physiotherapy instruction. Outcome Measures: percentage weight bearing was measured for each participant with both crutches and a 4WF both prior to and post physiotherapy instruction. Accuracy of partial weight bearing was measured using the NCounters device which was calibrated for each participant’s individual body weight to assess the accuracy of their respective attempts using each gait aid both before and after physiotherapy instruction.

Results: On initial attempt with crutches, subjects exceeded their 50%PWB (mean 58%, range 18-100%), 25% PWB (mean 36%, range 11-73%) and 5%PWB (mean 23%, range 4-64%) respectively. Volunteers performed better with a 4WF, however this did not reach statistical significance 50%PWB (mean 58% vs 38%, p= 0.07), 25%PWB (mena 36% vs 27%, p=0.33) or 5%PWB (mean 23% vs 16%, p=0.29). Following physiotherapy education, the 50%, 25% and 5%PWB attempts respectively averaged 31% (p=0.02), 15% (p=0.01) and 10% (p=0.04).

Conclusion: There is wide variability of PWB between individual with a tendency towards exceeding designated targets. Physiotherapy education and possibly use of 4WF over crutches demonstrated improved performance.

Keywords: Orthopaedic surgery, rehabilitation, physiotherapy