步兵踝关节肌力和跟腱横截面积与强化训练的关系

背景:军事训练中肌腱损伤和肌腱功能紊乱经常发生,但肌腱疾病准确的流行病学、病理生理以及愈合、修复机制尚不清楚,慢性肌腱功能紊乱引起疼痛的原因也有待研究。目的:评价强化训练对士兵踝关节肌力以及跟腱横截面积的影响,找到合适的快速提高体能的训练方法。设计:单一样本的分组对照。单位:解放军第四军医大学;解放军第一五○医院全军军事训练医学研究所。对象:实验于2004/03-06在解放军第一五○医院全军军事训练医学研究所进行。随机挑选新兵和常规训练1年的士兵各30名,均为男性,作为新兵组和老兵组。入伍年龄为17～18岁,入伍前均无参加专业体育训练史,无踝关节受伤史,均能承受正常的体能训练。方法:新兵组参加正常的体能训练(如投弹、5km越野跑等),同时进行踝关节背伸、跖屈的强化训练。具体为:提踵50次;在45°弧形仰卧起坐板上仰卧起坐50次。每项训练2次/d,持续8周。老兵组参加日常的体能训练。分别对训练前、训练8周后的新兵和老兵进行踝关节肌力等速测试和跟腱横截面积测量。主要观察指标:新兵训练前与强化训练8周后及老兵跟腱横截面积的比较和踝关节肌力的变化。结果:60名士兵全部进入结果分析。跟腱横截面积与体质量呈偏相关(r=0.446,P=0.015),训练前后跟腱横截面积无明显变化。训练后新兵和老兵的踝关节跖屈、背伸、外翻的相对峰力矩、耐力、力矩加速能等指标明显大于训练前的新兵(P<0.05),训练后的新兵和老兵之间无明显差异。结论:强化训练能在短期内快速促进体能储备;训练前后跟腱截面积无明显变化提示踝关节力量提高不是通过肌腱肥大实现的,可能与肌腱的内部改建有关。

Correlation of the muscular strength of ankle joint and the cross-sectional area of achilles tendon with forced training in infantry soldiers

BACKGROUND: Tendon injury and dysfunction often occurs in military training, but the exactly epidemiological, pathological, physiological, healing and remodeling mechanisms of tendonopathy is still unclear, even the pain due to chronic tendon dysfunction should be further studied.OBJECTIVE: To evaluate the effect of forced training on the muscular strength of ankle joint and the cross-sectional area (CSA) of achilles tendon of infantry soldiers, and look for effective training methods.DESIGN: One-sample contrasting study.SETTING: Fourth Military Medical University of Chinese PLA; InStitute of Military Training-related Medical Sciences, the 150 Hospital of Chinese PLA.PARTICIPANTS: The study was carried out in the Institute of Military Training-related Medical Sciences, the 150 Hospital of Chinese PLA from March to June 2004. Thirty male light infantry recruits and thirty one-year-trained male soldiers were regarded as recruit group and one-year soldier group. The enlisted age ranged from 17 to 18 years. Recruits did not have the history of special training and injury of ankle joints. All of them were able to undertake routinely physical training.METHODS: The recruits participated in routinely physical trainings, such as grenade throwing and 5 km cross-country race, and forced trainings, such as dorsiflexors and plantarflexors on ankle joint, twice a day for each training item for 8 successive weeks. The forced training included calf raise for 50 times and sit-ups for 50 times on 45° arched board.Moreover, one-year soldiers were undertaken routinely physical trainings. Eight weeks later, the isokinetic testing of ankle joint and CSA of achilles tendon were measured before and after trainings.MAIN OUTCOME MEASURES: Comparisons of CSA of achilles tendon and changes of muscular strength of ankle joint between recruits before routine training and after 8-week forced training and one-year soldiers after routine training.RESULTS: All 60 soldiers were involved in the final analysis. Partial correlation was showed between CSA and body weight (r =0.446, P=0.015), and there was no difference in CSA before and after training. The relative peak torque, endurance and torque acceleration energy of plantarflexors, dorsiflexors and evertors were distinctively higher in recruit group and one-year soldier group after training than those in recruit group before training (P ＜ 0.05); however, there was no difference between recruit group and one-year soldier group after training.CONCLUSION: Forced training method can improve physical readiness in a short time. No changes of CSA of achilles tendon after training show that the improvement of ankle muscular strength may be through the rebuilding of its inner-structure rather than through the hypertrophy of the tendon.