膝关节损伤后期屈膝肌与伸膝肌力矩比值的远期评价研究

测试并评价膝关节损伤后期膝屈伸肌峰力矩、屈膝肌峰力矩／伸膝肌峰力矩比值（Hamstring／quadriceps,H／Q）,以便明确不同测试速度时的H／Q比值与膝关节损伤后期膝关节功能之间的关系。应用Cybex－330型等速肌力测试训练系统对41例单侧膝关节损伤后期病人的双侧膝屈伸肌进行等速肌力测试评定;采用Lysholm膝评定量表对患侧膝主观及临床功能情况进行评定。膝关节损伤后期膝屈伸肌峰力矩、单次最大做功量、平均功率及相应的W／Q比值在不同测试速度（60°s、180°s）时患膝与健膝之间差异不明显;患膝W／Q比值在低（＜50％）、最佳（50％～80％）、高（＞80％）时相应的膝评定量表得分之间的相差也不明显;然而,患膝与健膝比较,当H／Q比值相差（≤15％与＞15％）时的膝评定量表得分之间差异才有显著性（P＜0．01）。膝关节损伤后H／Q比值是一个不确定值,患膝与健膝H／Q比值之间的相差应在15％以内;膝关节损伤后康复训练应达到的最佳W／Q比值应该是对未受损伤的健侧膝的H／Q值。     

中国女子篮球运动员膝关节等速肌力测试分析

目的:了解中国国家女子篮球队运动员膝关节等速肌力特征。方法:选用IsoMed 2000等速测试系统,采用60°/s、180°/s、240°/s三种角速度,测试18名中国女篮国家队运动员膝关节等速肌力。根据场上位置将运动员分为三组:后卫组7人(1、2号位),前锋组6人(3、4号位),中锋组5人(5号位),比较分析三组运动员的测试结果。结果:(1)女篮运动员双侧膝关节慢速测试时(60°/s)屈伸肌峰力矩(PT)显著高于快速测试(180°/s,240°/s),膝关节屈伸肌峰力矩比值(H/Q)随测试速度增加递增,左右膝H/Q无显著性差异。(2)慢速测试时(60°/s),左右膝关节峰力矩、峰力矩/体重比值、平均功率、H/Q无显著差异。(3)快速测试(240°/s)时,左膝屈肌PT、峰力矩/体重比值(PT/BW)显著高于右膝。180°/s测试时,左膝屈肌平均功率显著高于右膝。(4)60°/s测试时,后卫、前锋、中锋运动员PT、PT/BW组间比较无显著性差别。180°/s测试时,后卫运动员左膝屈肌PT与前锋、中锋运动员比较有显著性差异(P=0.02),各组间伸肌PT未见显著差异。240°/s测试时,后卫运动员右膝屈、伸肌PT/BW和中锋运动员比较均存在显著差异;后卫、前锋、中锋三组运动员平均功率、H/Q、总功与峰值功率组间比较均无显著性差别。结论:(1)女篮运动员快速测试(240°/s)时左膝屈肌力量强于右膝,反映快速运动时左右膝关节肌力不平衡。(2)不同场上位置女篮运动员膝关节等速肌力快速测试结果有差异性,提示力量训练应根据场上位置进行特异性训练。(3)女篮运动员需加强屈肌快速力量训练,以提高H/Q,预防膝关节损伤。     

腘绳肌等速离心训练对前交叉韧带重建术后膝关节功能的影响

目的:观察腘绳肌等速离心训练(IEE)对前交叉韧带重建术后膝关节功能的影响。方法:将42例前交叉韧带(ACL)重建术后患者随机分为对照组(n=21)和治疗组(n=21)。两组患者均分阶段给予常规康复干预,治疗组在此基础上于术后1个月开始使用Biodex等速训练系统进行一周2次的腘绳肌等速离心训练。两组患者于术后1个月和4个月时采用该等速测试系统在60°/s角速度下对患肢进行向心屈、伸膝峰力矩值(PT)、腘绳肌与股四头肌肌力比率(H/Q比率)及屈膝相对峰力矩(PT/BW)的测定,并用量角器对患肢进行主动伸膝角度(AAKE)测定以及采用Lysholm膝关节评分量表(LKSS)对膝关节功能进行评定(AAKE与LKSS评分统计不区分性别)。结果:术后第1个月,治疗组进行腘绳肌等速离心训练前,两组患者患侧膝关节的屈膝PT、H/Q比率、屈膝PT/BW、AAKE以及LKSS评分差异均无统计学意义。术后第4个月,除对照组H/Q比值没有明显改变外,两组患者的其余各项数据均明显优于组内术后第1个月评定所得的数据,差异有统计学意义(P<0.01);治疗组各项数据均优于对照组,差异有统计学意义(P<0.05),其中以治疗组H/Q比值及屈膝PT/BW增大最为明显(P<0.01)。结论:腘绳肌等速离心训练能进一步改善前交叉韧带重建术后的主动伸膝角度,增加屈膝肌力并提高膝关节功能。     

中国优秀U17男子足球运动员下肢肌肉力量比率与变向能力的关系

目的:探究中国优秀U17男子足球运动员的下肢腘绳肌/股四头肌肌力比率(hamstring/quadriceps ratio,H/Q比率)和变向能力的相关关系,为提升U17男子足球运动员的变向能力及预防下肢损伤提供依据。方法:对47名中国优秀U17男子足球运动员进行股四头肌和腘绳肌的向心收缩、离心收缩等速测试,并分别计算双下肢不同角速度下的传统H/Q比率(腘绳肌向心收缩峰值力矩/股四头肌向心收缩峰值力矩)和功能H/Q比率(腘绳肌离心收缩峰值力矩/股四头肌向心收缩峰值力矩)。同时,采用T型测试评价变向能力。采用皮尔逊相关探讨各比率和变向能力之间的相关性,并对存在相关的H/Q比率与变向能力进行多元回归分析。结果:非优势侧高速传统H/Q比率(r=0.44,P=0.002)、优势侧低速功能H/Q比率(r=-0.358,P=0.013)与T型测试成绩均存在显著性相关;两个变量可以共同解释T型测试成绩总方差的28.2%(R^2=0.282,F=8.640,P<0.01)。结论:对于中国优秀U17男子足球运动员而言,优势侧低速功能H/Q比率越大、非优势侧高速传统H/Q比率越小,变向速度越快;优势侧低速功能H/Q比率和非优势侧高速传统H/Q比率均对U17男子足球运动员的变向能力有预测作用,且非优势侧高速传统H/Q比率对变向能力影响更大。     

我国自由式滑雪空中技巧优秀运动员主要关节等速肌力特征

目的：对自由式滑雪空中技巧优秀运动员主要关节肌肉力量素质特征和规律进行分析,为专项体能训练以及制定青年运动员专项力量训练方法提供科学依据。方法：利用德国ISOMED2000等速肌力测试系统,对18名（男女各9名）优秀运动员髋、膝、踝关节和躯干力量进行测试。选取单位体重的峰值力矩PT/BW、屈/伸肌群比值H/Q和肌力下降率等为测试指标。按测试模式（向心、离心收缩）、测试速度（慢速、快速收缩）和测试侧别（左侧、右侧）分为3个因素,采用3因素（2×2×2）重复测量方差分析检验不同因素对髋、膝、踝关节和躯干力量的影响。结果：1）各因素的主效应均存在显著性差异（P<0.05）,模式×速度在PT/BW指标上的交互作用也显著（P<0.05）;2）髋关节：60°/s和180°/s时,屈肌群离心收缩力量和H/Q显著大于向心收缩（P<0.01）;3）膝关节：在向心和离心收缩时,180°/s的H/Q均显著大于60°/s(P<0.01);4）踝关节：左侧快速背伸肌群的PT/BW显著大于右侧（P<0.01）;5）躯干：60°/s向心收缩时的PT/BW显著大于180°/s(P<...     

下肢关节刚度对自由操落地冲击负荷的影响

目的:探讨下肢关节刚度对运动员下肢关节负荷的影响,为降低下肢损伤风险提供依据。方法:通过2台高速摄像机(300 Hz)采集男子自由操团身后空翻两周转体720°(后团720旋)落地站稳动作,利用SIMI解析(8 Hz)获取三维运动学数据,使用BRG.Life MODTM分别创建14环节人体刚体模型和自由操落地垫模型,模拟了人体不同下肢关节刚度条件下落地动作。结果:后团720旋落地,水平GRF分量约为2.5 BW,且膝、踝关节外展/外翻角速度较大,峰值负荷率约219.5 BW/s,峰值负荷率衰减为88.6 BW/s;膝、踝关节刚度增加40%,膝关节伸肌力矩峰值增加11.6%,屈肌力矩峰值降低5.2%;膝、踝关节刚度降低40%,膝关节伸肌力矩峰值降低21.9%。结论:后团720旋落地施加于膝、踝关节较大的横向作用力,冠状面关节力矩较大。增加膝、踝关节刚度,会增加膝关节伸肌力矩峰值,降低外展力矩峰值。     

优秀击剑运动员下肢三关节等速肌力测试分析

目的:研究我国优秀击剑运动员下肢髋、膝、踝三关节肌群等速肌力表现,找出薄弱肌群。方法:国家击剑队备战2008年奥运会重点队员26名,男女各13名,年龄23.1±2.36岁。在60°/s、240°/s速度下测定运动员双侧下肢髋、膝、踝屈伸肌群等速向心峰力矩。结果发现:(1)髋关节:在240°/s下双侧伸肌峰力矩均明显低于60°/s(P<0.05),60°/s和240°/s下双侧髋关节屈肌峰力矩无显著差异(P>0.05);男运动员两个速度下前腿伸肌峰力矩均显著高于后腿(P<0.05),女运动员无显著差异(P>0.05);两个速度下,运动员双腿屈伸肌峰力矩比值低于正常。(2)膝关节:60°/s时男运动员双腿屈伸肌峰力矩有显著差异(P<0.05),240°/s时双侧伸肌峰力矩有显著差异(P<0.05),女运动员两个速度下均无显著差异(P>0.05);60°/s时,女运动员前后腿屈伸肌峰力矩比值分别为0.56和0.54,男运动员分别为0.63和0.67;240/°s时男女前后腿屈伸肌峰力矩比值均在正常范围。(3)踝关节:60°/s时男运动员前腿踝关节屈伸肌峰力矩显著大于后腿(P<0.05),240°/s时无显著差异(P>0.05);两个速度下,女运动员踝关节屈伸肌峰力矩均无显著性差异(P>0.05);运动员踝关节屈伸峰力矩比值在两个速度下均低于正常。结论:优秀男子击剑运动员下肢关节等速肌力双侧不对称,女运动员不对称表现不明显;击剑运动员下肢薄弱肌群为后腿髋关节伸肌群、股后肌群、前腿股后肌群及踝关节背伸肌群。     

应用等速肌力测试评价膝前交叉韧带断裂重建术后康复的效果

目的:采用等速肌力测试系统测试前交叉韧带(ACL)断裂患者在重建术前、术后的肌肉力量,评价有、无严格的康复训练计划对患者康复效果的影响。方法:采用美国产Biodex System 3多关节等速肌力测试系统,以60°/s、120°/s两种速度测定67例膝关节前交叉韧带断裂及韧带重建术后6个月、12个月患者的股四头肌和腘绳肌肌力,包括峰力矩(PT)、峰力矩/体重比值(PT/BW)、总功(TW)、平均峰力矩(AVG PT)。将其中遵医嘱进行康复训练的24人作为康复训练组,另外无严格康复训练计划、自主活动的43人作为未康复训练组。结果:手术前患膝屈、伸肌群的PT、PT/BW、TW、AVG PT较健侧均显著降低;ACL重建术后6个月、12个月,两组患者股四头肌和腘绳肌肌力均较术前有所提高,其中未康复训练组患侧股四头肌肌力恢复至健侧70%左右,腘绳肌肌力恢复至健侧75%,康复训练组股四头肌和腘绳肌肌力分别恢复至健侧的80%和85%左右,高于未康复训练组,但与健侧相比仍有差距。结论:康复训练对ACL重建术后股四头肌和腘绳肌的肌力恢复有明显的作用。等速肌力测试是评价前交叉韧带重建术后康复效果的有效手段。     

自由体操落地致膝损伤的生物力学因素分析

目的:分析自由体操落地致运动员膝损伤的生物力学因素。方法:采用三维录像采集比赛中男子自由体操"直体后空翻转体540°"动作的运动学数据,建立仿真模型模拟不同体操落地垫力学特性和不同踝关节角度的落地动作,用地面反作用力、膝关节反作用力、膝关节力矩等指标综合分析运动员落地过程中膝的生物力学特征。结果:左、右脚垂直地面反作用力峰值呈非对称性(分别为48.27、43.18 N/kg);左膝比右膝使用相对较大的膝关节屈曲;峰值负荷率以及峰值负荷率衰减随落地垫刚度和阻尼的增加而增加;落地垫摩擦增加30%,左膝关节水平反作用力增加21.9%,左膝伸肌力矩、外展力矩均增加23%;踝背屈9°时左右下肢峰值负荷率及峰值负荷率衰减最大。结论:增加落地垫摩擦和踝跖屈均会增加膝负荷,落地垫摩擦和踝背屈是自由体操落地膝损伤的重要风险因素。     

短跑支撑期股后肌损伤的动力学分析

目的:本研究通过分析短跑途中跑支撑期下肢关节各种力矩分量,探寻下肢动力学与股后肌损伤的内在联系。方法:8名短跑运动员为受试者,采用即时红外高速摄影技术及三维测力台,引入环节互动动力学方法计算分析短跑最大速度阶段支撑期的下肢关节力矩,研究各种力矩分量(含肌肉力矩、地面反作用力力矩、惯性力矩等)在膝、髋关节处产生的作用,分析在支撑期股后肌的受力及作用情况。结果显示:触地初期,地面反作用力通过膝、髋关节前方,在膝关节处产生伸膝力矩,在髋关节处产生屈髋力矩,为抵抗这一力矩,股后肌群收缩产生屈膝力矩和伸髋力矩分别为231.09±99.04Nm和453.15±199.06Nm。结论:触地初期股后肌承受极大的负荷,是股后肌损伤发生的高危险期。     

肌电生物反馈训练对膝关节损伤后某些肌肉功能的影响

对40名男性受试者为时7周的训练表明,对膝关节损伤后进行康复训练,在肌力增长上,肌电生物反馈训练优于非肌电反馈训练(P<0.05)。     

Hamstring muscle strain recurrence and strength performance disorders

We determined the frequency of strength disorders in 26 athletes with a history of hamstring muscle injury and recurrent strains and discomfort. We also assessed the effectiveness of rehabilitation to correct muscle performance. After concentric and eccentric isokinetic assessment, 18 athletes were found to have strength deficits, as determined by statistically selected cutoffs of peak torque, bilateral differences, and the flexors/quadriceps ratio. The discriminating character of the eccentric trial was demonstrated, combining a preferential eccentric peak torque deficit and a significant reduction of the mixed eccentric flexors/concentric quadriceps ratio. The athletes with muscle imbalances followed a rehabilitation program individually adapted from their strength profile. Treatment length was from 10 to 30 sessions and resulted in isokinetic parameter normalization in 17 of 18 subjects. Isokinetically corrected subjects were observed for 12 months after return to athletics. None sustained a clinically diagnosed hamstring muscle reinjury. Subjective intensity of pain and discomfort were significantly reduced, and they all returned to their prior level of competition. These results demonstrate that persistent muscle strength abnormalities may give rise to recurrent hamstring injuries and discomfort. An individualized rehabilitation program emphasizing eccentric training based on specific deficits contributes to a decrease in symptoms on return to sports.     

Knee extension and flexion muscle power after anterior cruciate ligament reconstruction with patellar tendon graft or hamstring tendons graft: a cross-sectional comparison 3 years post surgery

Hamstring muscles play a major role in knee-joint stabilization after anterior cruciate ligament (ACL) injury. Weakness of the knee extensors after ACL reconstruction with patellar tendon (PT) graft, and in the knee flexors after reconstruction with hamstring tendons (HT) graft has been observed up to 2 years post surgery, but not later. In these studies, isokinetic muscle torque was used. However, muscle power has been suggested to be a more sensitive and sport-specific measures of strength. The aim was to study quadriceps and hamstring muscle power in patients with ACL injury treated with surgical reconstruction with PT or HT grafts at a mean of 3 years after surgery. Twenty subjects with PT and 16 subjects with HT grafts (mean age at follow up 30 years, range 20–39, 25% women), who were all included in a prospective study and followed the same goal-based rehabilitation protocol for at least 4 months, were assessed with reliable, valid, and responsive tests of quadriceps and hamstring muscle power at 3 years (SD 0.9, range 2–5) after surgery. The mean difference between legs (injured minus uninjured), the hamstring to quadriceps (H:Q, hamstring divided by quadriceps) ratio, and the limb symmetry index (LSI, injured leg divided by uninjured and multiplied by 100) value, were used for comparisons between the groups (analysis of variance). The mean difference between the injured and uninjured legs was greater in the HT than in the PT group for knee flexion power (–21.3 vs. 7.7 W, p = 0.001). Patients with HT graft had lower H:Q ratio in the injured leg than the patients with PT graft (0.63 vs. 0.77, p = 0.012). They also had lower LSI for knee flexion power than those in the PT group (88 vs. 106%, p < 0.001). No differences were found between the groups for knee extension power. The lower hamstring muscle power, and the lower hamstring to quadriceps ratio in the HT graft group than in the PT graft group 3 years (range 2–5) after ACL reconstruction, reflect imbalance of knee muscles after reconstruction with HT graft that may have a negative effect on dynamic knee-joint stabilization.     

Muscle torque in total knee arthroplasty: comparison of subvastus and midvastus approaches

The subvastus and midvastus approaches are two of the most commonly performed quadriceps preserving approaches for total knee arthroplasty (TKA), which can hasten functional recovery and rehabilitation. However, there has not been sufficient investigation with respect to a quantitative comparison between the two approaches in terms of muscle strength. To compare outcomes with respect to muscle strength between these two approaches, quadriceps and hamstring muscle torques of 20 patients who underwent primary TKA with the subvastus (SV) approach and 10 patients who received the midvastus (MV) approach were measured after surgery. The median age of patients in the SV group (68 years, range 53–77 years) was significantly different that the median age of patients in the MV group (61 years, range 50–73 years) (P = 0.0141). There was no significant difference in patient weight, height, or postoperative duration before muscle testing between the SV and MV groups. There were no significant differences in peak muscle torque or hamstring/quadriceps (H/Q) ratio between the groups. We thus conclude peak muscle torque and H/Q ratios were not statistically different with the SV or MV approach, therefore functional outcome is comparable.     

Hamstring and quadriceps strength balance in normal and hamstring anterior cruciate ligament-reconstructed subjects.

OBJECTIVE: The purpose of this study was to evaluate and characterize the agonist-antagonist strength balance (hamstring/quadriceps [H/Q] ratio and dynamic control ratio [DCR]) about the knee specific to velocity, range of motion, and contraction type. We hypothesized that there would be systematic variation in the H/Q ratio and DCR based on knee joint angle, angular velocity, and contraction type. We also hypothesized that these ratios would be altered in the anterior cruciate ligament (ACL)-reconstructed group in favor of protecting the ACL graft (relative knee flexor strength when strain on the ACL is the greatest). DESIGN: Cross-sectional design. SETTING: A tertiary care sport medicine clinic. PATIENTS OR PARTICIPANTS: Sixteen subjects more than 1 year after hamstring tendon ACL reconstruction were compared with 30 active uninjured control subjects. INTERVENTIONS: Isokinetic strength testing was performed over 5 degrees to 95 degrees knee joint range of motion, 5 angular velocities (50, 100, 150, 200, 250 degrees/s), for concentric and eccentric contractions. MAIN OUTCOME MEASUREMENTS: Angle and velocity-matched H/Q ratio maps and DCR maps were produced for each group. Difference maps allowed quantification of the differences between the groups. RESULTS: Angle and velocity-matched H/Q ratio maps demonstrated systematic variation based on joint angle, velocity, and contraction type for both the control (H/Q, approximately 0-1.42; DCR, approximately 0-1.57) and the ACL-reconstructed group (H/Q, approximately 0-1.33; DCR, approximately 0-1.35). Difference maps demonstrate regional (angle and velocity-specific) alteration in the ratio between the ACL-reconstructed and control groups. CONCLUSIONS: Specific imbalances were demonstrated in the ACL-reconstructed group compared with control. In high knee flexion angles, the low H/Q ratio may represent a compromised ability of the hamstrings to stabilize the knee joint throughout the full range of motion. Near full knee extension shifts in favor of the knee flexors may represent an attempt to stabilize the knee at the angle of greatest ACL strain. These finding have implications for graft donor site selection and postoperative rehabilitation as well as provide insight into the neuromuscular control of the knee.     

Acute effects of static stretching on peak torque and the hamstrings‐to‐quadriceps conventional and functional ratios

Recent evidence has shown acute static stretching may decrease hamstring‐to‐quadriceps (H:Q) ratios. However, the effects of static stretching on the functional H:Q ratio, which uses eccentric hamstrings muscle actions, have not been investigated. This study examined the acute effects of hamstrings and quadriceps static stretching on leg extensor and flexor concentric peak torque (PT), leg flexor eccentric PT, and the conventional and functional H:Q ratios. Twenty‐two women (mean ± SD age=20.6 ± 1.9 years; body mass=64.6 ± 9.1 kg; height=164.5 ± 6.4 cm) performed three maximal voluntary unilateral isokinetic leg extension, flexion, and eccentric hamstring muscle actions at the angular velocities of 60 and 180°/s before and after a bout of hamstrings, quadriceps, and combined hamstrings and quadriceps static stretching, and a control condition. Two‐way repeated measures ANOVAs (time × condition) were used to analyze the leg extension, flexion, and eccentric PT as well as the conventional and functional H:Q ratios. Results indicated that when collapsed across velocity, hamstrings‐only stretching decreased the conventional ratios (P<0.05). Quadriceps‐only and hamstrings and quadriceps stretching decreased the functional ratios (P<0.05). These findings suggested that stretching may adversely affect the conventional and functional H:Q ratios.     

Knee joint laxity and neuromuscular characteristics of male and female soccer and basketball players.

Anterior cruciate ligament injuries are occurring at a higher rate in female athletes compared with their male counterparts. Research in the area of anterior cruciate ligament injury has increasingly focused on the role of joint proprioception and muscle activity in promoting knee joint stability. We measured knee joint laxity, joint kinesthesia, lower extremity balance, the amount of time required to generate peak torque of the knee flexor and extensor musculature, and electromyographically assessed muscle activity in 34 healthy, collegiate-level athletes (average age, 19.6 +/- 1.5 years) who played soccer or basketball or both. Independent t-tests were used to determine significant sex differences. Results revealed that women inherently possess significantly greater knee joint laxity values, demonstrate a significantly longer time to detect the knee joint motion moving into extension, possess significantly superior single-legged balance ability, and produce significantly greater electromyographic peak amplitude and area of the lateral hamstring muscle subsequent to landing a jump. The excessive joint laxity of women appears to contribute to diminished joint proprioception, rendering the knee less sensitive to potentially damaging forces and possibly at risk for injury. Unable to rely on ligamentous structures, healthy female athletes appear to have adopted compensatory mechanisms of increased hamstring activity to achieve functional joint stabilization.