Validation Testing of a New Crutch Tip Biofeedback Device for Prescribed Lower Extremity Weight-Bearing

Modified weight-bearing recommendations are commonly prescribed after surgical intervention for injuries to the lower extremity to reduce the risk of nonunion and delayed healing associated with load bearing through the injured limb and to combat the deleterious effects of immobility. The physical therapist (PT) in the acute care setting is likely to instruct patients after lower extremity injury in weight-bearing-restricted ambulation. A new device is now available for use in the training of weight-bearing status. The study examines whether the ComeBack Mobility crutch tip reporting weight-bearing on the lower extremity is a reliable and valid tool in determining force when compared with the gold standard force plate measurement of lower extremity weight-bearing. Previous studies have shown that patients are often not able to adequately learn or adhere to restrictive weight-bearing modifications. This may be due to an inability to provide immediate and ongoing feedback on weight-bearing. The new ComeBack Mobility crutch tip system is now available for the acute care PT to use in instruction and for patients to receive real-time feedback throughout their rehabilitation process. A sample of convenience of 6 able-bodied PTs was used. Each subject performed 30 trials of axillary crutch-assisted weight-bearing ambulation using the new device. The weight-bearing reported by the device was compared with the weight-bearing measured through force plates via correlations, t tests, and Bland-Altman plot. The new device demonstrated moderate-good reliability in the measurement of non-weight-bearing and 50% partial weight-bearing in trials completed. The ComeBack Mobility crutch tip system could be useful and should be considered for clinical use as a reliable and valid tool in providing auditory feedback for compliance to a prescribed weight-bearing protocol. The system could be useful in the training of patients in the first use of crutches such as prior to discharge from an acute care hospital. Further research is needed with clinical populations as well as with varied weight-bearing protocols.