Mechanics of Ambulation With Standard and Spring-Loaded Crutches

Segura A, Piazza SJ. Mechanics of ambulation with standard and spring-loaded crutches.ObjectiveTo compare kinetic measures and spatiotemporal variables assessed during walking with standard axillary crutches and spring-loaded crutches.DesignA repeated-measures design in which healthy subjects walked with both standard and spring-loaded crutches.SettingBiomechanics research laboratory.ParticipantsTen healthy young adult volunteers participated. Only female volunteers between 154.9 and 175.3cm in stature were selected to fit the size of the crutches used.InterventionsNot applicable.Main Outcome MeasuresThe main outcome measures were kinetic variables such as ground reaction force, rate of force rise, and impulse and spatiotemporal variables such as stride length, stride time, and percentage of stride spent in stance.ResultsThe rate of ground reaction force rise and impulse of the ground reaction force (both P<.001) were reduced by 33% and 13% to 26%, respectively, but the peak ground reaction force was slightly greater (P=.001) with spring-loaded crutches. The stride time was increased with spring-loaded crutches (P=.005), but the stride length did not differ significantly (P=.465).ConclusionsThe use of spring-loaded crutches altered the mechanics of crutch gait in ways that are likely to reduce overuse injury in crutch users. Further study of spring-loaded crutches is warranted, especially with respect to their energetic efficiency.