半蹲式着陆腰部护具对脊柱-骨盆夹角及角速度的影响
Effect of lumbar braces on spine flexion angular velocity and spine-pelvic angle during half-squat parachute landing
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摘要: 目的 在佩戴不同腰部护具条件下,模拟空降平台半蹲式跳伞着陆(half-squat parachute landing,HSPL),分析腰部护具对脊柱屈曲活动的影响。方法 我科于2016年8月招募空降兵集训队共30名战士,男性,平均年龄(22.79±3.73)岁。分别进行不佩戴护腰(对照)、佩戴弹性护腰和半钢性护腰测试,每种防护测试分别从40 cm和120 cm平台跳下,以半蹲式着陆姿势着陆,双足落在测力台有效区域内。测试过程中使用Vicon动态捕捉系统记录脊柱-骨盆夹角(spine-pelvic angle,S-PA)和屈曲角速度(spine flexion angular velocity,SFAV)。同一高度及防护状态下重复测试3次,每次测试间隔2 min,取有效数据记录。结果 1)防护方式维度:40 cm高度,受试者佩戴半钢性护腰和弹性护腰与无护腰比较,脊柱-骨盆夹角增大,差异有统计学意义(158.78±12.49)°、(155.45±15.13)° vs (146.01±16.19)°,P均<0.05,三组间脊柱屈曲角速度差异无统计学意义(211.68±13.29)°/s vs (193.29±10.67)°/s vs (222.53±11.75)°/s,P均>0.05。120 cm高度,受试者佩带半钢性护腰、弹性护腰、无护腰时,脊柱-骨盆夹角依次降低,组间比较差异均有统计学意义(153.66±8.79)° vs(143.76±17.43)° vs (133.84±13.73)°,P均<0.05,前两组与无护腰比较,屈曲角速度均显著减小(311.85±17.26)°/s、(290.12±14.73)°/s vs (389.94±23.40)°/s,P均<0.05,但这两种护腰间差异无统计学意义(P>0.05)。2)高度维度120 cm较之于40 cm,无论是否佩戴护腰,脊柱-骨盆夹角均减小,脊柱屈曲角速度均增加,组间差异均有统计学意义(P<0.05)。结论 地面平台训练,护腰可以减少脊柱屈曲角度,降低脊柱屈曲角速度,半刚性护腰与弹性护腰相比,未显示出明显优势,弹性护腰可能更适合于空降部队训练防护。Abstract: Objective To simulate half-squat parachute landing (HSPL) with different protective lumbar brace and analyze the effect of lumbar brace on spine flexion-extension movement. Methods In August 2016,30 male soldiers from paratroops army with average age of 22.79±3.73 years were enrolled,and they had simulated a half-squat parachute landing by wearing different protective measures (no-brace,elastic brace and semi-rigid brace) in this study.Every parachutist jumped off from height of 40cm and 120cm and landed on the platform in HSPL.The dynamic landing process was recorded with a Vicon motion capture system.Spine-pelvic angle (S-PA) and the spine flexion angular velocity (SFAV) were collected and analyzed. Results In terms of effect of wearing brace,at 40cm height,,wearing elastic-brace and semi-rigid brace leaded to significantly higher S-PA when compared with no brace (155.45±15.13° and 158.78±12.49° vs 146.01±16.19°,P<0.05),but no significant difference in spinal flexion angular velocity was found (211.68±13.29°/s,193.29±10.67°/s and222.53±11.75°/s,P>0.05);at 120cm height,the S-PA in the elastic-brace condition,the semi-rigid brace condition and the no brace condition differed significantly (153.66±8.79° and143.76±17.43° vs 133.84±13.73°,P<0.05),with significantly difference between each condition;While the spinal flexion angular velocity in the elastic brace condition and semi-rigid brace condition reduced significantly compared with no brace condition (290.12±14.73°/s and311.85±17.26°/s vs 389.94±23.40°/s,P<0.05,respectively),but there was no statistically significant difference between the former two braces (P>0.05).With an increase in height of jumping,the S-PA in different conditions decreased significantly and the SFAV in different conditions increased significantly (all P<0.05). Conclusion Our findings indicate that lumbar brace may limit lumbar flexion range of motion and reduce spine flexion angular velocity during landing.The semi-rigid brace is not superior to the elastic brace for change of SFAV,and the elastic brace is suitable for airborne troops.
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