A Kinematic Comparison of Spring-Loaded and Traditional Crutches

作者：Seeley Matthew K^*; Hunter Iain; Bateman Thomas; Roggia Adam; Larson Brad J; Draper David O

来源：Journal of Sport Rehabilitation, 2011, 20(2): 198-206.

DOI：10.1123/jsr.20.2.198

• rehabilitation
• biomechanics
• mechanical energy
• gait speed

Context: A novel spring-loaded-crutch design may provide patients additional forward velocity, relative to traditional axillary crutches; however, this idea has not yet been evaluated. Objective: To quantify elastic potential energy stored by spring-loaded crutches during crutch-ground contact and determine whether this energy increases forward velocity for patients during crutch ambulation. Because elastic potential energy is likely stored by the spring-loaded crutch during ambulation, the authors hypothesized that subjects would exhibit greater peak instantaneous forward velocity during crutch-ground contact and increased preferred ambulation speed during spring-loaded-crutch ambulation, relative to traditional-crutch ambulation. Design: Within-subject. Setting: Biomechanics laboratory. Participants: 10 healthy men and 10 healthy women. Interventions: The independent variable was crutch type: Subjects used spring-loaded and traditional axillary crutches to ambulate at standardized and preferred speeds. Main Outcome Measures: The primary dependent variables were peak instantaneous forward velocity and preferred ambulation speed; these variables were quantified using high-speed videography and an optoelectronic timing device, respectively. Between-crutches differences for the dependent variables were evaluated using paired t tests (alpha = .05). Elastic potential energy stored by the spring-loaded crutches during crutch-ground contact was also quantified via videography. Results: Peak forward velocity during crutch-ground contact was 5% greater (P < .001) for spring-loaded-crutch ambulation than for traditional-crutch ambulation. Preferred ambulation speed, however, did not significantly differ (P = .538) between crutch types. The spring-loaded crutches stored an average of 2.50 +/- 1.96 J of elastic potential energy during crutch-ground contact. Conclusions: The spring-loaded crutches appear to have provided subjects with additional peak instantaneous forward velocity. This increased velocity, however, was relatively small and did not increase preferred ambulation speed.

• 出版日期2011-5