老年女性下肢关节等速肌力与骨密度的相关性研究

目的探讨老年女性膝、踝关节不同角速度等速肌力与骨密度的相关性,为针对性力量训练改善骨密度提供理论依据。方法采用Iso Med 2000等速肌力测试仪对42例健康老年女性,进行优势侧60°/s(5次)和180°/s(20次)膝、踝关节屈伸测试。肌肉峰力矩与优势侧股骨近端BMD进行主成分分析相关性。结果 1)与股骨颈BMD呈显著正相关肌力指标:膝关节伸肌绝对力、爆发力和肌耐力(r=0.572,r=0.662,r=0.691)。踝关节伸肌绝对力、爆发力和屈、伸肌耐力(r=0.429,r=0.667,r=0.617,r=0.509);2)与大转子BMD呈显著正相关肌力指标:膝关节屈肌爆发力和屈、伸肌耐力(r=0.522,r=0.526,r=0.525),踝关节伸肌爆发力和屈肌耐力(r=0.576,r=0.601);3)与Ward’s三角区呈显著相关肌力指标:膝关节伸肌绝对力(r=0.536),踝关节屈肌耐力(r=0.612)。结论加强老年女性大腿前群肌和小腿后群肌绝对力和爆发力,同时注重膝关节伸和踝关节屈耐力练习有利于提高股骨近端BMD。     

膝骨关节炎患者居家康复训练后膝关节屈伸肌力的变化

目的:评估膝骨关节炎患者居家康复训练后膝关节屈伸肌力的变化。方法:前瞻性纳入2020年5月至2021年10月收治的50例单侧膝骨关节炎患者,均接受3个月居家康复训练(包括健康指导和功能训练)。居家康复训练前、训练3个月后应用Biodex等速测试系统分别在慢速60°/s等速、中速120°/s等速和90°等长模式下对患者进行双膝屈伸肌力测试,记录峰力矩,同时记录疼痛视觉模拟评分(VAS)及西安大略省和麦克马斯特大学骨关节炎指数(WOMAC)评分,并进行比较。结果:训练前,患者患侧60°/s等速、120°/s等速、90°等长屈膝、伸膝肌力均弱于健侧(P均<0.05)。训练3个月后,患者除健侧60°/s等速伸膝肌力无明显变化外(P=0.183),其余肌力均较训练前提高(P均<0.05);患者患侧60°/s等速、120°/s等速、90°等长伸膝肌力仍弱于健侧(P均<0.01),但屈膝肌力差异无统计学意义(P均>0.05)。训练3个月后,患者疼痛VAS评分、WOMAC评分均较训练前改善(P均<0.01)。结论:膝骨关节炎患者居家康复训练3个月后膝关节屈伸肌力明显增强,...     

强化本体感觉训练及等速肌力训练对前交叉韧带重建术患者康复效果的影响

目的 探讨强化本体感觉训练及等速肌力训练对前交叉韧带（ACL）重建术患者康复效果的影响。方法选取2020年1月至2022年12月在我院诊治的ACL重建术患者82例,随机分为2组,每组各41例。对照组给予常规训练,研究组给予强化本体感觉训练及等速肌力训练。比较两组训练前后的膝关节本体感觉功能、等速肌力、关节疼痛程度及膝关节稳定性,以及康复效果。结果 训练后,两组患侧15°重现差值、患侧45°重现差值、患侧75°重现差值较训练前均降低（P<0.05）,且研究组明显低于对照组（P<0.05）。训练后,两组伸屈膝相对峰力矩（PT/BW）、屈膝峰力矩值（PT）、伸膝PT、腘绳肌与股四头肌的肌力比值（H/Q）均较训练前升高（P<0.05）,且研究组明显高于对照组（P<0.05）。训练后,两组视觉模拟评分法（VAS）评分、Lachman试验胫骨前移较训练前均降低（P<0.05）,且研究组明显低于对照组（P<0.05）。研究组康复优良率为90.24%,明显高于对照组的73.17%(P<0.05)。结论 强化本体感觉训练及等速肌力训练应用于ACL重建术患者,可有...     

缝匠肌自行滑脱重建伸膝功能1例报告

缝匠肌自行滑脱重建伸膝功能１例报告秦泗河患者男，２４岁，患儿麻后遗症左下肢不完全性瘫痪，肌力检查：踝关节的肌力皆４级，髋关节的肌力皆３～４级，绳肌肌力２级，股四头肌肌力２级，缝匠肌肌力５级，患肢在屈髋位膝关节无力伸直，当患肢在伸髋、伸膝位时，缝匠肌...     

腰椎管狭窄导致下肢功能下降的定量研究

目的　通过对腰椎管狭窄症患者的下肢肌力定量测定,定量分析腰椎管狭窄对下肢功能的影响。方法　采用CYBEX770P对需要进行手术治疗的腰椎管狭窄患者25例健侧和患侧肢体进行等速肌力测试,对测试结果进行对比分析。结果　患侧下肢在屈肌快速测试时的峰力矩、峰力矩/体重、平均功率、平均功率/体重、单次最佳做功量、单次最佳做功量/体重、30°力矩和30°力矩/体重均出现明显下降,较健侧有显著差异(P<0. 05)。患侧屈肌/伸肌的峰力矩结果与健侧比较无显著差异。结论　腰椎管狭窄症患者患肢伸侧和屈侧肌力下降程度不同,其中对屈肌肌力影响尤为显著。这与腰椎管狭窄引起肢体废用性有关,并且对屈肌影响更大。     

膝关节镜手术的临床疗效及对股四头肌■绳肌功能影响的等速测定研究

作者对３５例３７个膝关节半月板损伤及骨关节炎患者关节镜手术前后的临床功能指标及股四头肌、绳肌等速肌肉功能进行随访分析。结果表明：术前患侧股四头肌和绳肌的峰力矩、总功、平均功率和肌肉爆发力较健侧均有明显降低。术后３周上述指标有轻度提高，经４周等速肌肉功能锻炼，前三项指标有显著提高；关节疼痛、肌力和关节活动度有明显改善；而患侧绳肌与股四头肌峰力矩比率（Ｈ／Ｑ）有所下降。提出膝关节镜术后辅以等速肌肉功能锻炼以提高手术疗效的观点。     

股四头肌肌力及骨质疏松与膝骨关节炎的关系

目的探讨股四头肌肌力改变、骨密度变化与膝骨关节炎(OA)的关系。方法选择自2013年10月至2015年12月份期间,在广州医科大学附属第二医院就诊的374例患者,分别登记病患的年龄、体重、身高,行双膝关节负重正位X线拍片检查,根据膝OA诊断标准(《骨关节炎诊治指南》),将患者分为健康对照组(174例)与膝OA组(200例)。膝OA组患者按照OA的KellgrenLawrence分级标准分为5级,并根据患者的临床症状和X线表现不同,分成轻度组、中度组和重度组;运用双能X线骨密度仪分别测定骨密度;运用肌肉功能测量分析系统和等长肌力测试仪测定股四头最大肌力;将不同程度的膝OA与正常成人样本数据用SPSS 13.0软件进行方差分析、KruskalWallis检验和Bonferroni法,探讨下肢肌肉衰减和骨密度与膝OA之间的相关性。结果膝关节退行性变患者重度组普遍存在骨质疏松、患肢股四头肌肌力下降表现,较健康对照组(P0.05)、轻度组(P0.05)在患侧髋骨骨密度、股四头肌最大肌力、平均肌力等差异有统计学意义。结论退行性关节病患者常伴随有全身性的骨质疏松症(OP)、患肢股四头肌肌力下降表现。膝OA的严重程度与骨质疏松呈正相关,与患肢股四头肌肌力呈负相关。     

膝关节镜手术的临床疗效及对股四头肌Guo绳肌功能影响的等速测…

作者对３５例３７个膝关节半月板损伤及骨头节炎患者关节镜手术前后的临床功能指标及股四头肌、Ｇｕｏ绳肌等速肌肉功能进行随访分析。结果表明：术前患侧股四头肌和Ｇｕｏ绳肌的峰力矩，总功、平均功率和肌肉爆发力较健侧均有明显降低。术后３周上述指标有轻度提高，经４周等速肌肉功能锻炼，前三项指标有显著提高；关节疼痛、肌力和关节活动度有明显改善；而患侧Ｇｕｏ绳肌与股四头肌峰力矩比率（Ｈ／Ｑ）有所下降。提出膝关节镜术     

健将与一级女子举重运动员骨密度比较分析

目的比较同级别不同运动等级女子举重运动员骨密度(BMD)的差异,探讨相同训练方案不同力量负荷强度对运动员骨密度的影响。方法测试48 kg级别健将组(n=15)和一级组(n=16)下肢链等速蹬伸肌力,腰椎L2-4和下肢主要部位BMD,分析下肢等速肌力与骨密度的相关性。结果健将组的腰椎L2-4、股骨远端、髌骨BMD和下肢链收缩力峰力矩、拉长力峰力矩均显著大于一级组(P0.05);下肢收缩力矩和拉长力矩与腰椎L2-4(r=0.507,r=0.519)、髌骨(r=0.482,r=0.456)和胫骨近端(r=0.613,r=0.580)BMD呈显著正相关(P0.05)。结论长期"奥林匹克举重运动"对女子运动员BMD有促进作用,随着力量负荷强度增加,BMD也呈增加趋势。     

关节镜下采用腘绳肌肌腱和微型钢板纽扣重建后十字韧带

目的介绍在关节镜下利用绳肌肌腱和微型钢板纽扣重建后十字韧带(PCL)的方法,探讨其临床效果。方法对21例单纯PCL断裂的患者,在关节镜下利用绳肌肌腱和微型钢板纽扣进行重建,术后进行1年以上的随访,了解膝关节功能。结果术后3个月,所有患者均无伸膝受限,膝关节屈膝活动度均大于120°。术后1年,患肢的股四头肌-绳肌峰力矩比超过正常侧的90%;屈膝70°时后抽屉试验Ⅰ度阳性2例,其余均为阴性;屈膝30°时后抽屉试验Ⅰ度阳性6例,其余为阴性;膝关节功能Lysholm评分为90.7±2.3。结论在关节镜下利用绳肌肌腱和微型钢板纽扣重建PCL方法简单,能够可靠恢复膝关节功能。     

Distribution of bone mineral density at the proximal tibia in knee osteoarthritis

One hundred and thirteen knees with osteoarthritis (OA) were studied to assess the distribution of bone mineral density (BMD) in the proximal tibia and the potential relation between osteoarthritis and osteoporosis in evaluating hip BMD. All patients had severe knee pain and were diagnosed with Kellgren and Lawrence grade IV osteoarthritis. According to the magnitude of the axial deformity, four categories were created: varus>10 degrees ( 28.3%), varus 4-10 degrees (38.9%), aligned 180 +/- 3 degrees (13.3%), and valgus>4 degrees (19.5%). For each category, the medial and lateral proximal tibial density were assessed. BMD was measured at the femoral neck and at 14 regions of interest (ROI) in the proximal part of the tibia using dual X-ray absorptiometry. Based on the femoral neck BMD, patients were classified according to the World Health Organization (WHO) definition of osteoporosis. The mean knee BMD was positively correlated with the hip BMD value (knee BMD m = 0.38 + 0.73 x hip BMD, r = 0.60, P<0.001). The knee BMD distribution of the 113 patients was negatively correlated with the axial deformity (BMD MT-LT = 5.15 - 0.027 x HKA, r = 0.77, P<0.0001). In the varus deformity, BMD of the medial side was higher than that of the lateral side with an important asymmetry (0.587 g/cm2). This asymmetry was also found in the valgus deformity for the lateral side but was less important (-0.112 g/cm2). With equal deformity, the asymmetry of BMD was higher in varus deformity (0.587 g/cm2) than in valgus deformity (-0.112 g/cm2). Asymmetry of the knee BMD distribution revealed that progression of the deformity (either varus or valgus) with joint space narrowing led to an increase in the medio-lateral difference of the proximal tibia density. Lesser severity of Kellgren and Lawrence grades may reveal different results. Twenty patients with osteoporosis developed knee osteoarthritis (OA) and the relation between osteoporosis and knee OA remains unclear.     

Preoperative physical therapy in primary total knee arthroplasty

In order to evaluate the efficacy of preoperative physical therapy for patients undergoing elective primary total knee arthroplasty, 10 patients completed 6 weeks of physical therapy before surgery (PT group). Ten patients served as controls (C group). Subjects were tested at baseline (PT only), before surgery, 6 weeks after surgery, and 3 months after surgery using the Hospital for Special Surgery knee rating scale, range of motion, thigh circumference, walking speed, Cybex II isokinetic knee flexion, and extension testing, and computed tomography scanning for cross-sectional muscle area. Hospital stay and need for physical therapy after inpatient rehabilitation were also compared. Physical therapy produced modest gains in isokinetic flexion strength in these severely arthritic knees but no difference in extension strength. The decrease in isokinetic strength after surgery was not affected by preoperative physical therapy. Muscle area did not decrease significantly for the PT group, but it did decrease for the C group after surgery. While postoperative strength differences could not be demonstrated, preoperative physical therapy preserved thigh muscle area after surgery. The clinical significance of this finding is uncertain. Consequently, this study failed to support the routine use of preoperative physical therapy in knee replacement surgery.     

抗阻力量训练对青年和老年女性骨密度的影响

目的探讨相同负荷强度的抗阻力量训练对青年和老年女性骨密度的影响。方法身高、体重相匹配的青年组(n=36)和老年组(n=34)进行16w躯干、上下肢的抗阻力量训练。测试受试者腰椎(L_2~L_4)、股骨近端(股骨颈、Ward三角区、大转子)骨密度,拉力和下肢肌力。结果 (1)(3)干预后青年组股骨颈、Ward三角区和腰椎(L_2~L_4)BMD和拉力显著增大(P0.05),大转子BMD无显著变化;老年组股骨颈、Ward三角区和腰椎(L_2~L_4)BMD、拉力和下肢肌力显著增大(P0.05),大转子BMD无显著变化。(2)拉力与腰椎(L_2~L_4)、股骨颈、Ward三角区和大转子BMD呈显著正相关(r=0.642、0.686、0.600、0.781)、下肢肌力与腰椎(L_2~L_4)和Ward三角区BMD呈显著正相关(r=0.526,r=0.619)。结论 16 w力量训练改善了青年和老年女性腰椎和股骨近端的骨密度且无年龄差异,但对大转子骨密度改善不显著。     

Muscle-Bone Interactions Across age in Men

This study examined the relationship of muscular strength and lean tissue with age-related patterns in bone mineral density (BMD) in men 20-81 years of age. Subjects were assigned to one of three age groups, Young Men (YM), (n = 25, 20-39 yrs), Middle-aged Men (MM) (n = 24, 40-59 yrs), and Older Men (OM) (n = 23, 60-81 yrs). Isotonic and isokinetic strength was assessed for the quadriceps and hamstrings muscle groups. DXA (Lunar DPX-IQ) was used to measure spine, hip, and total body BMD and body composition. OM had significantly lower (p < 0.05) total lean body mass (LBM) than MM and lower leg lean mass (LM) than YM and MM. OM had significantly lower (p < 0.01) BMD than YM and MM at the femoral neck and total hip sites and a higher proportion of OM were osteopenic and osteoporotic at the total hip site. Isotonic and isokinetic strength for both muscle groups was positively related (p < 0.05) with the hip BMD sites (r = 0.38-.67). Leg LM also was positively related to hip BMD (r = 0.37-.58). Multiple Regression analyses determined that age and lean mass (LBM or leg LM) were significant predictors (p < 0.05) of femoral neck, and total hip BMD, while lean mass (LBM or leg LM) was a significant predictor (p < 0.05) of BMD at the spine and trochanter sites. Isotonic and isokinetic leg strength variables were significant predictors (p < 0.05) of the total body, total hip and trochanter BMD. In conclusion, leg strength, leg LM, and total LBM were significant predictors of BMD in men, independent of age. These findings emphasize the importance of maintaining lean body mass for the bone health of aging men.

Key Points

• Osteoporosis is an important health problem for men.
• Bone mineral density for the hip was lower in older men compared to their younger and middle-age counterparts. There were age group differences in the prevalence of osteopenia and osteoporosis for the total hip BMD site.
• Muscular strength and bone-free lean body mass were significant predictors of hip BMD, independent of age, thus reinforcing the importance of contractile forces on skeletal health.
• Maintenance of muscle mass and strength should be encouraged in aging men for the reduction of osteoporosis risk.

Key words: Lean body mass, osteopenia, osteoporosis, muscle strength, bone density     

孟德尔随机化探索骨密度与膝关节骨性关节炎的因果关联

目的 采用孟德尔随机化分析方法，探讨骨密度与膝关节骨性关节炎的因果关联。方法 利用全基因关联研究的数据进行分析，暴露因素为骨密度，包含全身骨密度、腰椎骨密度、股骨颈骨密度、足跟骨密度、前臂远端骨密度、前臂骨密度，结局变量为膝关节骨性关节炎。采用IVW法、MR-Egger法、WM法、Simple Mode法、Weighted Mode法进行孟德尔随机化分析，并进行异质性检验、敏感性分析、多效性分析。结果 全身骨密度IVW结果显示OR(95%CI)为1.08(1.02～1.14);腰椎骨密度IVW结果显示OR(95%CI)为1.09(1.01～1.18);股骨颈骨密度IVW结果显示OR(95%CI)为1.15(1.04～1.28);足跟骨密度IVW结果显示OR(95%CI)为1.04(0.99～1.08);前臂远端骨密度IVW结果显示OR(95%CI)为1.07(1.00～1.15);前臂骨密度IVW结果显示OR(95%CI)为0.97(0.86～1.10)。全身骨密度、腰椎骨密度、股骨颈骨密度的异质性检验均不存在异常变量，敏感性分析均显示稳健，且均未发现多效性。结论 全身骨密度、腰椎骨密...     

膝骨关节炎影像学分级同胫股及髌股关节轴线角相关性分析

目的:探讨膝骨关节炎影像学分级与胫股及髌股关节轴线角的相关性。方法:回顾性分析2018年9月至2020年12月行立位双下肢X线及膝关节侧位片检查的中老年KOA患者739例(1 026膝)。其中K-L0级患者63例(95膝);K-L 1级100例患者(130膝);K-L 2级161例患者(226膝);K-L 3级187例患者(256膝);K-L 4级228例患者(319膝)。依据膝关节中心和髋关节中心与踝关节中心连线的相对位置将患膝分为内翻组844膝及外翻组182膝。根据Install-Salvati法将患膝重新分为高位髌骨(髌骨高度>1.2 mm)347膝、中位髌骨(髌骨高度0.8～1.2 mm)561例、低位髌骨(髌骨高度<0.8 mm)118膝3组。测量并比较各组股骨下角,胫骨上角,股骨颈干角,股骨胫骨角,关节间隙角,髋-膝-踝角,髌骨股骨角及髌骨高度。结果:(1)在内翻型KOA组中,不同K-L分级患者的髋-膝-踝角、胫股角、股骨下角、胫骨上角、关节间隙角、股骨颈干角比较,差异有统计学意义(P<0.05)。髋-膝-踝角、胫股角、股骨下角、胫骨上角、关节间隙角与K-...     

Impact of degenerative spinal diseases on bone mineral density of the lumbar spine in elderly women

Degenerative diseases of lumbar spine commonly noted in elderly people may affect their lumbar spine bone mineral density (BMD). The aim of this study is to determine whether the degree of degenerative spinal diseases is correlated with lumbar spine and femoral neck BMD. This study included 630 women age 60 years or over (mean age 73.3 ± 6.9 years) visiting the Osteoporosis Outpatient Clinic at the Tokyo Metropolitan Geriatric Medical Center. Subjects underwent anteroposterior and lateral X-rays of the lumbar spine. The score of degenerative spinal diseases for each subject was calculated according to the scores for the Kellgren-Lawrence method, osteophyte formation, bone sclerosis, disk space narrowing, and spondylolisthesis involving L1-L2 through L4-L5 interspaces. Moreover, the number of vertebral fractures at L2 through L4 was recorded. The BMD of the second to fourth lumbar spine from anteroposterior projections and femoral neck were measured using an Expert-5000 (GE Lunar, Madison, WI USA). Most subjects had degenerative diseases of the lumbar spine. Scores for the Kellgren-Lawrence method, osteophyte formation, bone sclerosis, disk space narrowing, and spondylolisthesis were positively correlated with lumbar spine BMD, while they were not correlated with femoral neck BMD. Multiple regression analysis indicated that the scores for osteophyte formation, bone sclerosis, and disk space narrowing were independently correlated with lumbar spine BMD. Thus, in this study, the scores for degenerative spinal diseases were correlated with lumbar spine BMD, while they were not correlated with femoral neck BMD. This discrepancy indicates that degenerative spinal diseases are associated with increased lumbar spine BMD measurements. Femoral neck BMD therefore may be more appropriate than lumbar spine BMD in evaluating osteoporosis in elderly women.     

Contribution of Hip Abductors Muscles on Bone Mineral Density and Functionality in Older Women

Background: Despite the well-established role of muscle in maintaining bone mass and physical performance, there are still few studies that assess the relationship between muscle groups and specific bone sites and its contribution to physical function in older people. The aim of the study is to verify the association between hip and knee's muscle strength and bone mineral density of the femoral neck (BMD-FN) and investigated which muscle strength that are related with BMD-FN is associated with physical function in older women. Methodology: This is a cross-sectional study of 94 women over the age of 60 years, physically independent. Muscle strength of the hip and knee was evaluated using an isokinetic dynamometer (Biodex, USA) to obtain peak torque (PT). The BMD-FN was obtained using dual-energy x-ray absorption densitometry (DXA). Physical function was evaluated by the Timed Up and Go (TUG), gait speed (GS), five times stand to sit (5TSS) and single-leg stance (SS). To verify the association between muscle strength (independent variable) and the BMD-FN (dependent variable) and the relationship between muscle strength (independent variable) and clinical tests (dependent variable), the multiple linear regression was carried out, adjusted for age, time of menopause, height and level of physical activity. All of the analyses were carried out by the SPSS 17.0 software, with a level of p < 0.05 significance. Results: We found an association between the hip abductors PT and the BMD-FN and between hip abductors PT and all clinical tests. Conclusion: We observe that hip abductor muscle strength contributes to BMD-FN and to performance in several clinical tests in older women. These findings reinforce the importance of this musculature not only for improving balance and gait, but also it can be a strategy to maintain/improve bone mass in the femoral neck in this population.     

Gait abnormalities following slipped capital femoral epiphysis

The authors evaluated 30 subjects with treated unilateral slipped capital femoral epiphysis and a range of severity from mild to severe to characterize gait and strength abnormalities using instrumented three-dimensional gait analysis and isokinetic muscle testing. For slip angles less than 30 degrees, kinematic, kinetic, and strength variables were not significantly different from age- and weight-matched controls. For moderate to severe slips, as slip angle increased, passive hip flexion, hip abduction, and internal rotation in the flexed and extended positions decreased significantly. Persistent pelvic obliquity, medial lateral trunk sway, and trunk obliquity in stance increased, as did extension, adduction, and external rotation during gait. Gait velocity and step length decreased with increased amount of time spent in double limb stance. Hip abductor moment, hip extension moment, knee flexion moment, and ankle dorsiflexion moment were all decreased on the involved side. Hip and knee strength also decreased with increasing slip severity. All of these changes were present on the affected and to a lesser degree the unaffected side. Body center of mass translation or pelvic obliquity in mid-stance greater than one standard deviation above normal correlated well with the impression of compensated or uncompensated Trendelenburg gait.     

Long-term residual musculoskeletal deficits after femoral shaft fractures treated with intramedullary nailing

BACKGROUND: Locked intramedullary (IM) nailing has been recognized as one of the most reliable methods for treatment of femoral shaft fractures. Although IM nails are routinely used in the treatment of these fractures, the long-term effects of retained IM nails are unknown. METHODS: Seventeen patients with radiographically documented healed fracture of femoral diaphysis after locked IM nailing technique were evaluated at a follow-up of at least 18 months postoperatively. All patients had returned to their preinjury level of function and activity before the study. The bone mineral densities (BMD) of the injured and contralateral femora were measured using dual energy x-ray absorptiometry (DEXA). BMD of symmetrical regions in the femoral neck and medial and lateral femoral cortex of the implanted and contralateral femora were compared. Postinjury muscle function was assessed from measurement of the isometric strength of six separate muscle groups (quadriceps, hamstrings, hip extensors, hip flexors, hip abductors, and hip adductors) in treated and control extremities. RESULTS: The average BMD of the femoral neck region of instrumented femora was 9% less than in contralateral control. Within the medial cortex, BMD of the control femora was an average of 20% greater than in the implanted side. In the lateral cortex, the difference averaged 13%. The isometric dynamometric data demonstrated a statistically significant reduction in the strength of the quadriceps of the instrumented extremities as compared with the contralateral ones. There was no significant difference in the strength of the hamstrings, hip extensors, hip flexors, abductors, or adductors. In the control extremities, the average torque generated by isometric contraction of the quadriceps was 3.45+/-1.35 times greater than by the hamstrings. Torque in extension/flexion and abduction/adduction was also observed. CONCLUSION: Our data suggest that limbs with long-term retained IM nails experience a significant reduction in the femur BMD and quadriceps muscle strength. These findings may not be simply related to the implant, and further study is warranted to determine the causes of these changes.