Dept of Exercise Sciences, Brigham Young University, Provo, UT, USA.
J Sport Rehabil. 2011 May;20(2):198-206. doi: 10.1123/jsr.20.2.198.
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.
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.
Within-subject.
Biomechanics laboratory.
10 healthy men and 10 healthy women.
The independent variable was crutch type: Subjects used spring-loaded and traditional axillary crutches to ambulate at standardized and preferred speeds.
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 (α = .05). Elastic potential energy stored by the spring-loaded crutches during crutch-ground contact was also quantified via videography.
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.
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.
新型弹簧式腋拐设计可能会使患者在使用腋拐时获得比传统腋拐更大的前进速度，但这一理念尚未得到验证。
定量分析弹簧式腋拐在触地过程中存储的弹性能，并确定其是否会增加患者在使用腋拐时的前进速度。由于在行走过程中，弹簧式腋拐很可能会存储弹性能，作者推测与传统腋拐相比，弹簧式腋拐能使患者在触地过程中表现出更大的峰值瞬时前进速度，并在使用弹簧式腋拐时表现出更高的习惯性行走速度。
自身对照。
生物力学实验室。
10 名健康男性和 10 名健康女性。
独立变量为腋拐类型：参与者使用弹簧式和传统腋拐以标准化和习惯性速度行走。
主要因变量为峰值瞬时前进速度和习惯性行走速度；分别采用高速录像和光电定时装置对这两个变量进行定量分析。使用配对 t 检验（α=0.05）评估腋拐间的因变量差异。还通过录像定量分析弹簧式腋拐在触地过程中存储的弹性能。
弹簧式腋拐在触地过程中的峰值前进速度比传统腋拐高 5%（P＜0.001）。然而，两种腋拐的习惯性行走速度差异无统计学意义（P=0.538）。弹簧式腋拐在触地过程中平均存储 2.50±1.96 J 的弹性能。
弹簧式腋拐似乎为患者提供了更大的峰值瞬时前进速度。然而，这种速度的增加相对较小，并没有提高习惯性行走速度。
