肌肉含量指标对绝经后女性骨质疏松症发生风险的预测价值分析

目的 评价肌肉含量指标与骨密度(bone mineral density, BMD)的关联性,筛选预测绝经后女性骨质疏松(osteoporosis, OP)发生风险的最佳部位肌肉指标及其截止点。方法 选取2018年1月至2021年10月贵州医科大学附院健康管理中心的1366名绝经后女性,采用DXA和BIA测量BMD和四肢骨骼肌含量(ASM),以ASM算出各肌肉含量指标：ASMI、ASM_BMI及SMI。应用ROC曲线及Logistic回归分析验证肌肉指标对OP风险的预测能力及评估关联强度。结果 OP组的肌肉含量低于非OP组,除腰椎BMD间的SMI和股骨颈、腰椎BMD间的内脏脂肪面积及大粗隆、全髋BMD间的ASM_BMI差异无统计学意义(P>0.05),各部位不同BMD间脂肪、肌肉含量指标差异均有统计学意义(P<0.05)。Pearson分析显示,各部位BMD与SMI呈负相关(r=-0.095、-0.122、-0.195、-0.177);与ASM、ASM、ASM_BMI呈正相关(r=0.369、0.298、0.085...     

肾功能正常的中老年人群血清肌酐水平与骨密度相关性研究

目的探讨肾功能正常的中老年人群血清肌酐水平与骨密度相关性。方法数据来源于在我院接受治疗的864名(457名男性和407名绝经后女性)年龄为45～75岁且估计肾小球滤过率60 mL (min·1. 73 m~2)的患者。通过双能X线吸收测定法测量受试者骨密度(bone mineral density,BMD)和附肢肌肉质量(appendicular skeletal muscle,ASM)。受试者工作特征曲线分析显示,肌肉减少症血清肌酐的切点在男性中低于0. 88 mg/dL,在女性中低于0. 75 mg/dL。根据肌肉减少症血清肌酐的临界值,将受试者分为两组:低肌酐组和高肌酐组。结果在调整年龄的偏相关分析中,血清肌酸酐与BMD和ASM均呈正相关。低血清肌酐的受试者在调整混杂因素后,男性股骨颈、全髋和腰椎以及女性全髋、腰椎的低BMD(T值为-1. 0)的风险较高。血清肌酐的增加与男女全髋和腰椎出现低BMD的可能性降低显著相关[男性:全髋,优势比(OR)=0. 84,95%CI=0. 74～0. 96;腰椎OR=0. 8,95%CI=0. 68～0. 96;女性:全髋OR=0. 83,95%CI=0. 73～0. 95;腰椎OR=0. 81,95%CI=0. 67～0. 99]。结论低血清肌酐与肾功能正常受试者的低密度独立相关。     

绝经后女性肌肉质量的影响因素研究

目的 探讨广州市绝经后女性肌肉质量的相关影响因素。方法 收集2019年6月至2020年12月广州市120名自愿参加本研究的绝经后女性的临床资料;其中符合纳入标准的有90例,年龄47～88岁,平均年龄(62.4±7.5)岁。所有受试者均记录其年龄、绝经年龄、绝经年限和身高、体重,计算BMI数值并进行骨密度测定、体成分分析检测肌肉质量。根据ASMI数值将受试者分为肌肉减少组及非肌肉减少组;分析两组年龄、绝经年龄、绝经年限和BMI数值、骨密度及肌肉质量的差异,比较两组患骨质疏松症的比率,利用Pearson相关性分析研究各因素与肌肉质量的相关程度,利用多元线性回归分析分析各指标与肌肉质量的相关性并得出回归方程。结果 肌肉减少组BMI和ASMI数值低于非肌肉减少组(P<0.05);肌肉减少组发生骨质疏松的比例大于非肌肉减少组(P>0.05); Pearson相关性分析提示绝经年龄(r=0.262,P=0.012)和BMI(r=0.771,P<0.001)与ASMI呈正相关;多元线性回归分析显示,影响绝经后女性ASMI值的因素主要有绝经年龄(P=0.037,B=0.034)和BM...     

绝经后女性握力与骨密度的相关性研究

目的研究绝经后女性握力和骨密度的相关性。方法对120例绝经后女性进行握力测量和骨密度测定,观察≤60岁组、61~70岁组和70岁组的握力和骨密度变化,应用单因素Person相关性分析和散点图研究握力与骨密度的相关性。结果最大握力:≤60岁组25.86±4.77 kg,61~70岁组23.37±4.64 kg,70岁组16.63±5.40 kg。骨密度测定提示:65例股骨颈T值≤-2.5;90例腰椎T值≤-2.5。最大握力与骨密度均随年龄增加而减少。握力与股骨颈和腰椎骨密度呈非常显著正相关。结论绝经后女性握力越大,股骨颈和腰椎骨密度越高。     

北京市中老年女性月经及身体成分与骨密度的相关性研究

目的调查北京市中老年女性年龄、月经和身体成分特征,分析其与骨密度的关系以及对骨密度的影响。方法招募45～80岁女性384名,调查受试者月经状况,包括初潮年龄、绝经年龄和绝经年限;测试受试者腰椎、左股骨颈、左髋以及全身骨密度,并测试全身脂肪和肌肉含量,由此计算脂肪含量指数(fat mass index,FMI)、肌肉含量指数(lean mass index,LMI)和四肢骨骼质量指数(appendicular skeletal muscle mass index,ASMI)。采用Pearson相关和多元逐步回归模型分析各因素与骨密度的关系。结果相关性结果显示,年龄、绝经年限、初潮年龄与骨密度呈显著负相关,绝经年龄、LMI、FMI和ASMI与骨密度呈显著正相关。多元逐步回归分析结果显示,绝经年限与各部位骨密度均呈显著负相关,ASMI与各部位骨密度均呈显著正相关,FMI仅与全髋和全身骨密度具有显著相关性,初潮年龄和绝经年龄仅与腰椎和全身骨密度具有显著相关性。结论绝经年限是中老年女性骨密度的独立危险因素,而ASMI则为独立保护因素,绝经年龄、初潮年龄以及FMI对中老年女性骨密度的影响存在部位差异性。     

绝经后妇女血脂水平与骨密度的关系

目的 明确绝经后妇女血脂水平与骨密度有否联系。方法 测定85例绝经后妇女的甘油三酯和胆固醇水平，双能X线法测定腰椎k2-4和股骨颈的骨密度(BMD)。结果 与未绝经妇女相比，绝经后妇女甘油三酯(t=3．74，P=0．000)和胆固醇(t=3．75，P=0．000)水平均显著升高；而BMD腰椎k(t=2．43，P=0．017)和股骨颈(t=3．32，P=0．002)均显著降低；绝经后妇女甘油三酯水平与股骨颈的BMD经BMI校正后有显著负相关，偏相关系数r=-0．324，P=0．003；而与腰椎k2-4 BMD无相关。胆固醇水平则与股骨颈及腰椎k2-4的BMD均无相关性。结论 绝经后妇女甘油三酯水平的升高可能是绝经后骨量减少及骨质疏松发生的因素之一。     

血清催产素浓度与绝经后女性骨密度相关性研究

目的探讨催产素与绝经后妇女骨代谢指标以及腰椎和髋部骨密度之间相关性。方法检测185例骨密度正常和132例患骨质疏松症女性的血清催产素、瘦素、雌激素和骨代谢指标浓度。腰椎和股骨颈的BMD通过双能X线吸收法测量。结果患骨质疏松症女性的血清催产素浓度低于骨密度正常的女性(P0.05)。骨质疏松症组中血清催产素浓度与年龄、绝经年限、体质量指数(body mass index,BMI)和血清PINP、BLAP和CTX浓度呈负相关;与瘦素和雌激素具有明显正相关性;在正常骨密度组中,血清催产素浓度和各种指标未发现明显的相关性。调整年龄和BMI后,腰椎和股骨颈骨密度仍然与绝经年限以及血清PINP、BLAP和CTX浓度呈负相关,与雌激素、瘦素和催产素浓度呈正相关。对年龄和BMI进行调整后,进行多元回归分析显示绝经年限、血清催产素、PINP和CTX是腰椎和股骨颈骨密度的显著预测因子。结论绝经后女性患者较高的血清催产素水平与较高的腰椎和股骨颈骨密度有关。     

绝经后女性血清硒水平与骨质疏松骨密度和骨代谢指标相关性研究

目的探索血清硒水平与绝经后妇女骨代谢指标以及腰椎和髋部骨密度之间相关性。方法检测156例正常骨密度和162例骨质疏松症的血清硒、25-羟基维生素D、PTH、骨钙素、PINP、CTX和NTX/Cr等指标水平。腰椎和股骨颈的BMD通过双能X线吸收法测量。探索了血清硒水平与骨密度的关系。结果骨质疏松症女性的血清硒水平低于正常骨密度的女性(P0.05)。在骨质疏松症妇女中,血清硒水平与年龄、绝经年限、BMI、PTH、骨钙素、PINP、CTX和NTX/Cr水平呈负相关,与25-羟基维生素D水平呈正相关。在正常骨密度组,血清硒水平与这些参数均未发现明显的相关性。调整年龄和BMI后,腰椎和股骨颈骨密度与血清硒及25-羟基维生素D水平呈显著正相关,与绝经年限、PTH、骨钙素、PINP、CTX和NTX/Cr呈负相关。对年龄和BMI进行调整后,进行多元回归分析以确定BMD的预测因子,血清硒和PINP、CTX是腰椎和股骨颈骨密度的显著预测因子。结论绝经后女性患者血清硒水平降低与腰椎和股骨颈骨密度降低密切有关。     

老年女性2型糖尿病患者骨密度与握力的相关性研究

目的探索老年女性2型糖尿病患者骨密度与握力的相关性。方法选取首都医科大学宣武医院内分泌科住院的≥60岁的女性2型糖尿病患者共112名,计算体重指数(BMI),测定糖化血红蛋白(HBA1c),C反应蛋白(CRP),白细胞介素6(IL-6)水平及握力;采用双能X线吸收仪测定四肢骨骼肌肌肉含量(ASM)及骨密度(BMD)。分析骨密度与握力,四肢骨骼肌肌肉含量及炎症因子的相关性。结果老年女性糖尿病患者骨质疏松组BMI、四肢骨骼肌肌肉含量,握力显著低于非骨质疏松组(P0.001)。两组CRP,IL-6无显著差异。相关分析显示年龄与左、右股骨颈的骨密度显著负相关(分别为r=-0.248,P=0.008;r=-0.232,P=0.014)。四肢骨骼肌含量与腰椎的骨密度显著正相关(r=0.280,P=0.003)。BMI、握力与双侧股骨颈骨密度及腰椎骨密度均显著正相关(r=0.207~0.372,P0.05~P0.001)。多元Logistic回归分析显示,BMI、握力是影响骨质疏松的独立危险因素(分别为OR=1.24,P=0.002;OR=1.14,P=0.005)。结论握力而不是肌肉含量是影响老年女性2型糖尿病患者骨质疏松的独立危险因素。     

重庆地区围绝经期与绝经后妇女骨密度及身体成分相关指标分析

目的 调查重庆地区围绝经期与绝经后妇女(5~10年）骨密度及相关身体成分指标,分析身体成分指标与骨密度的关系,为本地区骨质疏松的防治提供线索。方法 ①选取2017年于本院进行健康体检年龄≥45岁的妇女956名(排除相关原发疾病）,其中围绝经期510名,绝经后446名,并分别记录身高、体重,计算出体质量指数(body mass index, BMI）;②使用美国GE公司双能X线骨密度仪测定受试者腰椎1~4、左侧股骨颈、大转子、股骨干、全髋的骨密度以及全身脂肪、肌肉含量与骨矿含量。结果 一般情况分析发现,重庆地区围绝经期妇女身高明显高于绝经后妇女［分别为(156.81 ± 5.27) cm、(153.32 ±5.51) cm］,而体质量指数无明显差异。 绝经后妇女肌肉含量(37.91 ± 6.42) kg、脂肪含量(17.84 ± 2.16) kg、骨矿含量(1.58±0.41) kg均较围绝经期妇女 [(37.88 ± 6.15) kg、(19.21 ± 2.07) kg、(1.75±0.20) kg ]降低。绝经后妇女诊断骨质疏松与低骨量的比例分别为28.92%、41.03%,高于围绝经期妇女低骨量的发生率(28.63%)。围绝经期妇女腰椎1~4和左侧股骨颈、大转子、股骨干及全髋骨密度 (bone mineral density, BMD)明显高于绝经后妇女［分别是(1.0 959 ± 0.1 603) g/m2和(0.8 410 ± 0.1 606) g/m2,(0.8 178 ± 0.1 577) g/m2和(0.7 872 ± 0.1 585) g/m2,(0.6 946 ± 0.1 252) g/m2和(0.6 728±0.1 274) g/m2,(1.0 329 ± 0.1 712) g/m2和(1.0 030±0.1 737) g/m2,(0.8 773 ± 0.1 448) g/m2和(0.8 495 ± 0.1 478) g/m2］。结论 绝经后妇女髋部、腰椎等部位BMD均较围绝经期妇女明显降低;骨质疏松及低骨量的发生率随年龄增加显著升高;和围绝经期妇女相比,绝经后妇女全身脂肪含量偏低;BMD与全身肌肉含量呈正相关性。     

老年人躯干肌群与髋部肌群相关性研究

目的探讨老年人躯干肌群与髋部肌群体质成分含量的相关性。方法收集2017年3月至5月来我院体检的新街口社区60～85岁中老年人316名,其中,男性122名,女性194名。CT扫描得到志愿者腹部和髋部图像,使用东软医疗系统有限公司开发的高级可视化后处理工作站(advanced visualization workspace,AVW),分别定量测量L_3椎体中份层面和小转子下3 cm垂直股骨长径横截面的肌群面积(cross-sectional muscle area,CSMA)、肌肉间隙脂肪面积(inter-muscular adipose area,IMAA)、肌肉脂肪浸润程度(muscle fat infiltration,MFI)。用单样本K-S检验正态性;使用组内相关系数(interclass correlation coefficient,ICC)评价两名测量者组间重复性及一名测量者两次测量的组内重复性;使用独立样本t检验比较男、女两组间一般情况、躯干和髋部肌群CSMA、IMAA、MFI结果的差异;Pearson相关性比较两组L_3水平躯干肌群和髋部肌群体质成分的相关性,再分别以L_3 CSMA、IMAA、MFI为因变量,髋部CSMA、IMAA、MFI为自变量做多元逐步回归分析,确定影响躯干肌群体质成分的主要影响因子。P0.05,差异有统计学意义。结果男性躯干和髋部CSMA大于女性,两个部位MFI程度小于女性。Pearson相关分析显示男、女躯干CSMA、IMAA、MFI与髋部CSMA、IMAA、MFI成正相关,其中,男性躯干肌肉面积与髋部肌肉面积相关性最高。结论老年躯干肌群与髋部肌群体质成分改变具有相关性,男性躯干肌肉面积与髋部肌肉面积相关性最高。     

胫神经腓肠肌肌支离断术治疗小腿腓肠肌肥大

目的:探讨一种简单、安全、有效的小腿肌肉肥大的治疗方法。方法:选择典型的小腿肌肉肥大病例,静脉+局麻下在腘窝横纹中央切开1.2～1.5cm皮肤、皮下组织,找到胫神经的腓肠肌内、外侧头肌支,用神经探测仪确定后离断。结果:自2005年共完成400例,经6～24个月随访,平均12个月,效果满意,小腿围较术前缩减3.63±1.10cm(P0.001),不影响小腿功能。结论:本法操作简单、效果明显,病人痛苦小,恢复快,符合美容手术微创的原则。     

Physiological fatigue of smooth muscle contractions in rat urinary bladder

OBJECTIVE: To characterize the physiological fatigue in bladder smooth muscles that can occur within 60 s of stimulation, which is closer to the duration of normal voiding. MATERIALS AND METHODS: Longitudinal and transverse strips of rat bladder were used; the muscles were mounted in an in vitro multi-muscle chamber, and the decline in contractile tension recorded during continuous electrical stimulation at frequencies of 5-30 Hz for 60 s. The effect of muscle length on fatigue was assessed by monitoring the decline in tension during 30 Hz stimulation at rest length, and at 60% and 100% stretched lengths of the bladder strips. To assess some of the factors involved in the development of fatigue, tension responses of fatigued muscles were monitored on exposure to 80 mm potassium or 1 microm bethanechol. RESULTS: In both longitudinal and transverse bladder strips stimulated at 30 Hz, peak contractile tension declined to 50% of original after approximately 33 s, and to 30% after 60 s of stimulation. After 10 s rest, 60% of the original tension was recovered. Increasing the frequency of fatigue stimulation from 5 to 30 Hz significantly increased the extent of the decline in tension and reduced the time to a 50% decrease in tension. Stretching the bladder strips from rest length to 100% stretched length significantly reduced the extent of tension decline and increased the time to a 50% decrease in tension. Exposure of fatigued muscles to high potassium or bethanechol generated more tension than electrical stimulation. CONCLUSION: Contractile fatigue occurs in both longitudinal and transverse strips of the bladder smooth muscles within the duration of normal voiding. Increasing the frequency of stimulation from 5 to 30 Hz increased the degree and rate of fatigue. Stretching the bladder strips from rest length by 60-100% reduced the degree and rate of fatigue. Bladder fatigue may be caused by decreased depolarization of the smooth muscle membranes, reduced release of acetylcholine from presynaptic nerve terminals, or by other yet undetermined mechanisms.     

经眼轮匝肌下额肌瓣悬吊术矫治重度上睑下垂

目的:使额肌瓣悬吊术矫治上睑下垂,特别是重度上睑下垂的损伤更小,更符合生理功能。方法:根据上睑解剖特点,改进传统的额肌瓣,术式的关键是额肌瓣在眼轮匝肌的深面与眶隔之间分离。结果:临床应用矫治上睑下垂51例63只眼,经过2周至1年的随访,除1只眼过度矫正,14只眼略显矫正不足外,其余48只眼睑裂正常,睑裂弧度自然,术后闭目不全现象3个月后逐渐消失。结论:该术式操作方便,损伤小,术后恢复快,效果可靠持久。     

Longitudinal evaluation of local muscle conditions in a rat model of gastrocnemius muscle injury using an in vivo imaging system

This study aimed to evaluate the time course of local changes during the acute phase of gastrocnemius muscle strain, in a rat model, using an in vivo imaging system. Thirty‐eight, 8‐week‐old Sprague‐Dawley male rats were used in our study. Experimental injury of the right gastrocnemius muscle was achieved using the drop‐mass method. After inducing muscle injury, a liposomally formulated indocyanine green derivative (LP‐iDOPE, 7 mg/kg) was injected intraperitoneally. We evaluated the muscle injuries using in vivo imaging, histological examinations, and enzyme‐linked immunosorbent assays. The fluorescence peaked approximately 18 h after the injury, and decreased thereafter. Histological examinations revealed that repair of the injured tissue occurred between 18 and 24 h after injury. Quantitative analyses for various cytokines demonstrated significant elevations of interleukin‐6 and tumor necrosis factor‐α at 3 and 18 h post‐injury, respectively. The time course of fluorescence intensity, measured using in vivo imaging, demonstrated that the changes in cytokine levels and histopathologic characteristics were consistent. Specifically, these changes reached peaked 18 h post‐injury, followed by trends toward recovery. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1034–1038, 2015.     

Inhibition of ADAM10 in satellite cells accelerates muscle regeneration following muscle injury

Muscle injury is one of the most common orthopedic and sports disorders. For severe cases, surgical repair may be indicated; however, other than immobilization and the administration of anti‐inflammatory drugs there is currently no effective conservative treatment for this condition. Satellite cells (SCs) are muscle‐specific stem cells and are indispensable for muscle regeneration after muscle injury. SCs are activated upon muscle injury to proliferate and differentiate into myoblasts, which subsequently fuse into myofibers and regenerate the damaged muscle. We have previously shown that ADAM10, a membrane‐anchored proteolytic enzyme, is essential for the maintenance of SC quiescence by activating the Notch signaling pathway in SCs. Because suppression of ADAM10 activity in SCs can activate SC differentiation, we asked whether inactivation of ADAM10 in SCs after muscle injury could enhance muscle regeneration. Using Adam10 conditional knockout mice, in which ADAM10 activity can specifically be suppressed in SCs, we found that partial inactivation of ADAM10 accelerates muscle regeneration after muscle injury. Nearly identical results were obtained by the administration of GI254023X, a selective ADAM10 inhibitor. The findings of the present study thus indicate that transient enhancement of SC differentiation after muscle injury expedites muscle regeneration and that ADAM10 can be a potential molecular target in treating muscle injuries. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2259–2265, 2018.

     

Relative contributions of muscle activation and muscle size to plantarflexor torque during rehabilitation after immobilization.

Muscle atrophy is clearly related to a loss of muscle torque, but the reduction in muscle size cannot entirely account for the decrease in muscle torque. Reduced neural input to muscle has been proposed to account for much of the remaining torque deficits after disuse or immobilization. The purpose of this investigation was to assess the relative contributions of voluntary muscle activation failure and muscle atrophy to loss of plantarflexor muscle torque after immobilization. Nine subjects (ages 19-23) years with unilateral ankle malleolar fractures were treated by open reduction-internal fixation and 7 weeks of cast immobilization. Subjects participated in 10 weeks of rehabilitation that focused on both strength and endurance of the plantarflexors. Magnetic resonance imaging, isometric plantarflexor muscle torque and activation (interpolated twitch technique) measurements were performed at 0, 5, and 10 weeks of rehabilitation. Following immobilization, voluntary muscle activation (56.8 +/- 16.3%), maximal cross-sectional area (CSA) (35.3 +/- 7.6 cm(2)), and peak torque (26.2 +/- 12.7 N-m) were all significantly decreased ( p < 0.0056) compared to the uninvolved limb (98.0 +/- 2.3%, 48.0 +/- 6.8 cm(2), and 105.2 +/- 27.0 N-m, respectively). During 10 weeks of rehabilitation, muscle activation alone accounted for 56.1% of the variance in torque ( p < 0.01) and muscle CSA alone accounted for 35.5% of the variance in torque ( p < 0.01). Together, CSA and muscle activation accounted for 61.5% of the variance in torque ( p < 0.01). The greatest gains in muscle activation were made during the first 5 weeks of rehabilitation. Both increases in voluntary muscle activation and muscle hypertrophy contributed to the recovery in muscle strength following immobilization, with large gains in activation during the first 5 weeks of rehabilitation. In contrast, muscle CSA showed fairly comparable gains throughout both the early and later phase of rehabilitation.     

Effect of three anaesthetic techniques on isometric skeletal muscle strength

Background. Our aim was to quantify human involuntary isometricskeletal muscle strength during anaesthesia with propofol, sevoflurane,or spinal anaesthesia using bupivacaine. Methods. Thirty-three healthy patients undergoing anaesthesiafor elective lower limb surgery were investigated. Twenty-twopatients received a general anaesthetic with either propofol(n=12) or sevoflurane (n=10); for the remaining 11 patientsspinal anaesthesia with bupivacaine was used. We used a non-invasivemuscle force assessment system before and during anaesthesiato determine the contractile properties of the ankle dorsiflexormuscles after peroneal nerve stimulation (single, double, triple,and quadruple stimulation). We measured peak torques; contractiontimes; peak rates of torque development and decay; times topeak torque development and decay; half-relaxation times; torquelatencies. Results. Males elicited greater peak torques than females, medians6.3 vs 4.4 Nm, respectively (P=0.0002, Mann-Whitney rank-sumtest). During sevoflurane and propofol anaesthesia, muscle strengthdid not differ from pre-anaesthetic values. During spinal anaesthesia,torques were diminished for single-pulse stimulation from 3.5to 2.0 Nm (P=0.002, Wilcoxon signed rank test), and for double-pulsefrom 7.6 to 5.6 Nm (P=0.02). Peak rates of torque developmentdecreased for single-pulse stimulation from 113 to 53 Nm s^–1and for double pulse from 195 to 105 Nm s^–1. Torque latencieswere increased during spinal anaesthesia. Conclusions. At clinically relevant concentrations, propofoland sevoflurane did not influence involuntary isometric skeletalmuscle strength in adults, whereas spinal anaesthesia reducedstrength by about 20%. Muscle strength assessment using a devicesuch as described here provided reliable results and shouldbe considered for use in other scientific investigations toidentify potential effects of anaesthetic agents. Br J Anaesth 2004; 92: 367–72     

Transabdominal ultrasound measurement of pelvic floor muscle activity when activated directly or via a transversus abdominis muscle contraction

AIMS: The purpose of the present study was to compare the effectiveness of instruction to contract the pelvic floor muscles (PFM), the transversus abdominis (TrA), and the TrA + PFM visualized as displacement of the pelvic floor by ultrasound. MATERIALS AND METHODS: Twenty female physical therapists, mean age 41.1 years (range 26-56) participated in the study. A 3.5 MHz 35 mm curved linear array ultrasound transducer (Dornier Medtech) was placed in the mid-sagittal plane immediately suprapubically, angled at 15-30 degrees from the vertical depending on subcutaneous fat and anatomical variations, to image the pelvic floor. Six trials of three maneuvers in random order were performed: contraction of PFM, TrA, and TrA + PFM. RESULTS: In spite of correct contractions assessed by palpation and clinical observation, one subject demonstrated a downward movement of the pelvic floor during PFM contraction on ultrasound. Six subjects (30%) showed a downward movement during a TrA- contraction, and two during the combined TrA + PFM contraction. Instruction to contract PFM produced significantly greater mean displacement: 11.2 mm (95% CI 7.2-15.3) than TrA 4.3 mm (95% CI -0.2-8.8), P < 0.01, and combination: 8.5 mm (95% CI 5.2-12), P = 0.04. Hence, instruction of PFM contraction produced a 61.6% greater displacement of the pelvic floor in the correct direction than a TrA contraction. CONCLUSIONS: It is concluded that ultrasound is a more valid method than palpation and clinical observation to assess PFM function, and that instruction to contract the PFM produces a significantly more effective pelvic floor muscle contraction than instruction to perform a TrA contraction.