The impact of non weight bearing: A prospective cohort study

Patients with lower limb injuries are commonly advised to non weight bear (NWB) on their injured limb as part of treatment. Occasionally, patients complain that offloading one limb, associated with the use of crutches or other mobility aids, may lead to pain on one of the other supporting limbs. This has led to compensation claims (1) but has never been the subject of formal research.

A prospective cohort trial was undertaken to address this question. Patients were recruited from two Metropolitan Hospital Orthopaedic Fracture Clinics and Orthopaedic Wards. A survey was administered at two time points; the first at the point of definitive orthopaedic treatment and commencement of the NWB phase. The second after the NWB phase was completed. The surveys included a pain Visual Analogue Scale (VAS), Short Form (SF)12, a pain body chart and a health questionnaire.

A total of 55 patients were enrolled in the study. Seven patients developed new joint pain after a period NWB. These patients scored significantly lower on the follow up SF12 when compared to those who did not develop new pain (p=0.045). Follow up phone calls at least 6 months following completion of the second survey revealed that all initial and new pain areas in these participants had resolved. The main limitation of this study was the limited numbers.

This study supports the idea that crutches, prescribed in the short term to allow a limb to be NWB, achieve this aim with minimal impact. Their use may be associated with new other joint pain however it can be anticipated this will resolve after cessation of crutch use.