Dempsey Paddy C, Handcock Phil J, Rehrer Nancy J
a School of Physical Education, Sport and Exercise Sciences , University of Otago , Dunedin , New Zealand.
J Sports Sci. 2014;32(4):301-6. doi: 10.1080/02640414.2013.823226. Epub 2013 Sep 20.
We investigated the effect of added load and intense exercise on jump and landing performance and ground reaction force (GRF) during landings where attentional demand was varied. Fifty-two males (37 ± 9.2 years, 180.7 ± 6.1 cm, 90.2 ± 11.6 kg, maximal aerobic fitness (VO(₂max)) 50 ± 8.5 ml (.) kg(-1 .) min(-1), BMI 27.6 ± 3.1, mean ± s) completed a VO(₂max) test. Experimental sessions were completed (≥4 days in between) in a randomised counterbalanced order, one while wearing body armour and appointments (loaded) and one without load (unloaded). A vertical jump, a drop landing concentrating on safe touchdown, a drop jump and a drop landing with an attentional distraction were performed. These were repeated 1 min after a 5-min treadmill run. Mean jump height decreased by 12% (P < 0.001) with loading and a further by 6% following the running task. Peak GRFs were increased by 13-19% with loading (P < 0.001) depending on the landing task demands and a further by 4-9% following intense exercise. The distracted drop landing had significantly higher GRFs compared to all other landings. Results demonstrate that added load impacts on jumping and landing performance, an effect that is amplified by prior intense exercise, and distraction during landing. Such increases in GRF apply to police officer performance in their duties and may increase the risk of injury.
我们研究了在注意力需求不同的着陆过程中，额外负荷和高强度运动对跳跃及着陆表现以及地面反作用力（GRF）的影响。52名男性（年龄37±9.2岁，身高180.7±6.1厘米，体重90.2±11.6千克，最大有氧适能（VO₂max）为50±8.5毫升·千克⁻¹·分钟⁻¹，体重指数27.6±3.1，均值±标准差）完成了一次VO₂max测试。实验环节以随机平衡顺序完成（中间间隔≥4天），一次穿着防弹衣和装备（有负荷），一次无负荷（无负荷）。进行了垂直跳跃、专注安全触地的下落着陆、下落跳跃以及注意力分散的下落着陆。在5分钟跑步机跑步后1分钟重复这些动作。有负荷时平均跳跃高度下降了12%（P<0.001），在跑步任务后又进一步下降了6%。根据着陆任务需求，有负荷时峰值GRFs增加了13%-19%（P<0.001），在高强度运动后又进一步增加了4%-9%。与所有其他着陆相比，注意力分散的下落着陆GRFs显著更高。结果表明，额外负荷会影响跳跃和着陆表现，这种影响会因先前的高强度运动以及着陆时的注意力分散而放大。GRF的这种增加适用于警察履行职责时的表现，可能会增加受伤风险。
