脑卒中偏瘫患者膝过伸步态与下肢肌肉激活功能的相关性

目的 观察脑卒中膝过伸患者步行时膝关节过伸角度与下肢各关节运动学参数及下肢主要肌肉激活情况的相关性。方法 2020年8月至2021年9月,在同济大学附属养志康复医院选择伴膝过伸的脑卒中患者24例,以及性别、年龄、身高及体质量匹配并伴膝过伸的健康人24例,采用三维运动捕捉系统和无线表面肌电采集系统进行分析,记录骨盆、髋、膝、踝关节在矢状面上的角度,以及双侧臀大肌、股二头肌、股内侧肌、腓肠肌内侧头肌电数据。结果 脑卒中患者单腿支撑相的最大膝过伸角度时,各关节角度和各肌肉激活度均与健康人有非常显著性差异(|t|> 3.080, P <0.01)。脑卒中患者单腿支撑相的最大膝过伸角度与臀大肌激活度明显负相关(r=-0.532,P <0.01);两组膝过伸最大角度与踝跖屈角度呈显著正相关(r> 0.686, P <0.001)。结论 脑卒中患者膝过伸步态的矫正不仅需要关注膝关节控制,还需要关注踝关节控制和臀肌功能。     

小腿假肢对线对膝关节肌肉活动特性的影响

目的：研究小腿假肢对线对患者站立状态下膝关节肌肉活动特性的影响。探索最优对线的生物力学依据。方法：针对矢状面不同的对线角度，采用NoraxonTM TeleMYO 2400R表面肌电信号采集系统，测量健侧和残侧有关的10组肌肉的表面肌电信号。结果：为保持站立状态下膝关节稳定，残侧股二头肌和股内侧肌的等张收缩程度高于健侧：调整矢状面对线角度会改变健侧的腓肠内、外肌和残侧股内、外侧肌的收缩程度，当腿管相对于接受腔的屈伸角从一60增大＋60到时．以上肌肉的表面肌电绝对平均值变化幅度达一倍以上。而双侧股二头肌、健侧股四头肌肌群收缩程度几乎不变。结论：小腿假肢矢状面对线对患者站立状体下膝关节肌肉和健侧踝关节肌肉活动特性影响明显，以上结果为假肢的优化对线提供了直观定量的生物力学依据．可以结合残侧承重线、足底压力的分析，寻找指导对线的原则。     

Relationship between wire EMG activity,muscle length,and torque of the hamstrings

OBJECTIVE: To determine the effect of change of muscle length on the torque and wire electromyographic activity of six knee flexor muscles. DESIGN: Maximum isometric knee flexion torque and wire EMG data were collected at nine different positions. BACKGROUND: In vivo EMG-length-tension relationship is difficult to determine because of the interaction between muscle length and moment arm. The study of two-joint muscles allows the change of muscle length at one joint while preserving stable mechanical relationships at the other. This model facilitates understanding of length-tension and EMG-length relationship in vivo. METHODS: Nineteen subjects performed maximum isometric knee flexion contraction at nine positions of varying hip and knee angles. Wire EMG activity was recorded from semitendionsus, semimembranosus, long and short head of the biceps femoris, gracilis and sartorious muscles. RESULTS: As the two-joint hamstrings were lengthened, torque was significantly increased. Maximum isometric torque ranged from 257 to 716 kg cm. The ratio of the torque values to EMG activity of all muscles was increased at longer muscle lengths. A change in the muscle length of the two-joint hamstrings did not produce a consistent change of EMG activity. The short head of the biceps femoris and sartorius muscles increased their activity as the angle of knee flexion increased. CONCLUSIONS: Maximum torque of knee flexion occurs at the most lengthened position of the hamstrings. EMG activity did not consistently change with the change in muscle length. RELEVANCE: Understanding in vivo length-tension relationship and associated EMG activity is important for designing rehabilitation protocols, tendon lengthening and transfer and interpretation of EMG data.     

扁平足楼梯行走的下肢表面肌电特性

目的 探究楼梯行走时扁平足下肢肌肉在运动控制中的表现。方法 2019年3月至6月,招募男性受试者20例,其中正常足10例,扁平足10例(均为左脚),运用Noraxon表面肌电系统采集平地行走、楼梯行走时左右胫骨前肌(TA)、内侧腓肠肌(MG)、外侧腓肠肌(LG)、股直肌(RF)、股二头肌(BF)表面肌电信号,分析平均幅值和积分肌电的变化。结果 上楼梯时,扁平足TA、RF、BF的平均幅值大于正常足(|t| > 2.461, P< 0.05);下楼梯时,扁平足MG的平均幅值大于正常足(t = -1.976, P< 0.05),BF的平均幅值小于正常足(t = 2.298, P< 0.05);与平地行走相比,扁平足上楼梯时TA、RF、BF的平均幅值增加(|t| > 2.257, P < 0.05),下楼梯时RF、BF的平均幅值增加(| t| > 2.630, P < 0.05)。上楼梯时,扁平足TA、MG、LG、RF和BF的积分肌电均大于正常足(| t| > 2.492, P < 0.01);下楼梯时,扁平足MG的积分肌电大于正常足( t = -5.271, P < 0.05),BF的积分肌电小于正常足( t = 2.685, P < 0.05);与平地行走相比,扁平足上楼梯时TA、MG、LG、BF的积分肌电均增大(| t| > 2.088, P < 0.05),下楼梯时TA、LG、RF的积分肌电均降低( t > 2.059, P < 0.05)。 结论 楼梯行走时,扁平足为控制关节过度外旋,肌肉出现补偿反应。     

Joint loading and bone mineral density in persons with unilateral, trans-tibial amputation

Background. Persons with unilateral, lower-extremity amputation sometimes develop osteoarthritis in the intact limb. The purpose of this study was to investigate gait mechanics and bone mineral density in unilateral, trans-tibial amputees to test the hypotheses that the intact limb knee and hip will have larger frontal plane net joint moments and bone mineral density than the prosthetic side and the limbs of control subjects.

Methods. Proximal tibia and femoral neck bone mineral density and gait mechanics were measured from nine subjects with a unilateral, trans-tibial amputation and from age, gender, and mass matched control subjects.

Findings. The amputee intact proximal tibia bone mineral density and peak knee internal abduction moment were 45% (P = 0.001) and 56% (P = 0.028) greater, respectively, than the prosthetic side. The intact limb femoral neck bone mineral density and peak hip internal abduction moment were 12% (P = 0.095) and 33% (P = 0.03) greater, respectively, than the prosthetic side. The intact knee frontal plane moment and bone mineral density were moderately larger than the control knee, while the intact and control hip were similar.

Interpretation. Elevated frontal plane net joint moments and bone mineral density suggest the potential exists for premature knee joint degradation. Measuring frontal plane joint mechanics and bone mineral density may be important tools for assessing joint health in persons with unilateral, trans-tibial amputation.     

In vitro biomechanical study of femoral torsion disorders: Effect on moment arms of thigh muscles

Background

Lower limb torsion disorders have been considered as a factor inducing gonarthrosis and the three-dimensional effect of the surgical correction is not well reported yet. This paper reports an in vitro study aiming at quantifying the relationships between experimental femoral torsion disorders and moment arms of thigh muscles.

Methods

Five unembalmed lower limbs were used and fixed on an experimental jig. Muscles were loaded and 6 Linear Variable Differential Transformers were used to measure tendon excursions. Experimental osteotomies were performed to simulate torsions by steps of 6° up to 18°. Moment arms of the main thigh muscles were estimated by the tendon excursion method during knee flexion.

Findings

Moment arms of the tensor of fascia latae, the gracilis and the semitendinosus were significantly influenced by experimental conditions while the rectus femoris, the biceps femoris and the semimembranosus did not show modifications. Medial femoral torsion decreased the moment arm of both the gracilis and the semimembranosus. Opposite changes were observed during lateral femoral torsion. The moment arm of the tensor of fascia latae decreased significantly after 30° of knee flexion for 18° of medial femoral torsion.

Interpretation

Our results showed that medial and lateral femoral torsion disorders induced alterations of the moment arms of the muscles located medially to the knee joint when applied in aligned lower limbs. These results highlight a potential clinical relevance of the effect of femoral torsion alterations on moment arms of muscles of the thigh which may be related, with knee kinematics modifications, to the development of long-term knee disease.     

In vivo determination of the patella tendon and hamstrings moment arms in adult males using videofluoroscopy during submaximal knee extension and flexion

OBJECTIVE: The determination of patella tendon and hamstrings moment arms. DESIGN: The moment-arms were determined using a videofluoroscopy imaging method. BACKGROUND: The determination of hamstrings and quadriceps moment arms is important for the examination of muscle and joint forces in biomechanical applications. METHODS: Ten males performed one knee extension-flexion movement at a very slow (non-constant) angular velocity in front of the image intensifier screen of a videofluoroscopic system. The image of a calibration phantom with 2 cm squares was also recorded. Thirty five calibration points with known coordinates were digitized for the establishment of the polynomial equations that determined the coordinates of any point in the calibration phantom from its corresponding video coordinates. Fourteen control points were digitized and the difference between the actual and predicted coordinates was measured. The patella tendon and hamstrings (biceps femoris) moment arms to the tibiofemoral contract point were calculated. RESULTS: The mean error in the digitizing of the control points using the image deformation method ranged from 0.182 mm to 0.267 mm. The mean patella tendon moment arm ranged from 36.91 (SD 3.2) mm to 42.63 (SD 4.5) mm. The hamstrings moment arm ranged from 23.93 (SD 2.59) to 28.25 (SD 3.04) mm. CONCLUSION: The patellar tendon and hamstring moment-arms were determined using a videofluoroscopy method with acceptable accuracy. These parameters can be used for the biomechanical analysis of knee joint movements in two dimensional applications.     

24式简化太极拳野马分鬃动作导致膝关节损伤的风险评估

目的 通过力学分析评估24式简化太极拳野马分鬃动作不同姿位的损伤风险。方法 建立太极拳野马分鬃动作的力学模型,通过图像分析研究大腿和小腿的坐标、速度、加速度和水平角的数据,X片测量股四头肌的力臂,比较高、低姿位野马分鬃动作的股四头肌拉力、股胫关节作用力和髌股关节压力。结果 与高姿位相比,低姿位时上端环节质心坐标及速度均变小,右膝关节中心坐标和速度也降低,膝关节角度从128°降到115°;膝关节力矩、股四头肌拉力、股胫关节水平作用力和垂直作用力、股胫关节承受总载荷和髌股骨关节压力均显著增加(F> 37.187, P <0.001)。结论 采用低姿位练习太极拳野马分鬃动作,膝关节受伤风险较高。     

Three-dimensional geometry of the human biceps femoris long head measured in vivo using magnetic resonance imaging

Background

The human biceps femoris long head is susceptible to injury, especially when sprinting. The potential mechanical action of this muscle at a critical stage in the stride cycle was evaluated by calculating three-dimensional lines-of-action and moment arms about the hip and knee joints in vivo.

Methods

Axial magnetic resonance images of the right lower-limb (pelvis to proximal tibia) were recorded from four participants under two conditions: a reference pose, with the lower-limb in the anatomical position and the hamstrings relaxed; and a terminal swing pose, with the hip and knee joints flexed to mimic the lower-limb orientation during the terminal swing phase of sprinting and the hamstrings isometrically activated. Images were used to segment biceps femoris long head and the relevant bones. The musculotendon path and joint coordinate systems were defined from which lines-of-action and moment arms were computed.

Findings

Biceps femoris long head displayed hip extensor and adductor moment arms as well as knee flexor, abductor and external-rotator moment arms. Sagittal-plane moment arms were largest, whereas transverse-plane moment arms were smallest. Moment arms remained consistent in polarity across all participants and testing conditions, except in the transverse-plane about the hip. For the terminal swing pose compared to the reference pose, sagittal-plane moment arms for biceps femoris long head increased by 19.9% to 48.9% about the hip and 42.3% to 93.9% about the knee.

Interpretation

Biceps femoris long head has the potential to cause hip extension and adduction as well as knee flexion during the terminal swing phase of sprinting.     

膝骨关节炎患者膝关节置换后下肢肌的表面肌电图变化

背景：膝骨关节炎患者膝关节置换后下肢肌功能恢复一直存在着争议。目的：评价膝骨关节炎患者膝关节置换手术后下肢肌肉功能。方法：应用TELEMYO2400RG2表面肌电图遥测仪对25例双膝骨关节炎单膝关节置换后患者在平常自然步态下进行双下肢股直肌、胫前肌、股二头肌和腓肠肌内侧的表面肌电信号测试。在肌电图测试前,对患者双膝关节功能进行美国特种外科医院膝关节评分。结果与结论：患者置换后美国特种外科医院膝关节评置换侧平均分91．44,其优良率达100％;未置换侧平均分54．52。置换侧在疼痛、关节功能方面有明显改善;膝关节置换后置换侧股直肌、胫前肌、股二头肌的肌电振幅、肌电积分、平均频率、中位频率的（平均值、最小值、最大值）与未置换侧相比差异无显著性意义（P〉0．05）;置换侧腓肠肌内侧肌电振幅值及肌电积分值显著大于未置换侧（P〈0．05）;置换侧腓肠肌内侧平均频率、中位频率与未置换侧相比差异无显著性意义（P〉0．05）。提示膝关节置换后置换侧的下肢肌没有恢复到正常的功能活动水平,因此膝关节置换后康复要特别重视患者的肌肉锻炼。     

Co-activation is not altered in the contra-lateral limb of individuals with moderate knee osteoarthritis compared to healthy controls

BackgroundContra-lateral knee joint function in individuals with moderate knee osteoarthritis is not well understood, despite the functional burden of bilateral osteoarthritis on end stage clinical management. The purpose of this study was to determine whether co-activation and joint biomechanics are altered in the contra-lateral limb compared to age-matched controls.Methods20 Individuals with moderate knee osteoarthritis and 20 asymptomatic individuals walked on an instrumented dual belt treadmill at a self-selected speed. Surface electromyography of the knee joint musculature, including quadriceps, hamstrings and gastrocnemius muscles, normalized to maximum voluntary isometric contractions, as well as sagittal plane motion and sagittal and frontal plane moments were collected. Co-contraction indices were calculated and discrete variables from motion and moment data were extracted. Two-sample t-tests and 2-sample mixed model ANOVAs were performed with alpha <0.05.FindingsContra-lateral knee muscle co-activation differences were not found between groups (p > 0.65). Peak knee adduction moment (0.41 Nm/kg vs. 0.32 Nm/kg) and knee adduction moment impulse (0.14 Nm s/kg vs. 0.10 Nm s/kg) were higher in the contra-lateral limb compared to the asymptomatic group respectively, whereas the sagittal motion (9.8° vs. 14.4°) and moment ranges (0.66 Nm/kg vs. 0.86 Nm/kg) during stance were less dynamic (p < 0.03).InterpretationThe contra-lateral limb was functioning differently biomechanically despite no changes present in muscle co-activation. Findings suggest biomechanical changes are occurring without greater demand on the neuromuscular system to preserve contra-lateral joint function in moderate knee osteoarthritis gait. A greater focus should be made to address biomechanical abnormalities in both knees of individuals with moderate unilateral symptomatic knee osteoarthritis.     

Effects of stimulated hip extension moment and position on upper-limb support forces during FNS-induced standing--a technical note.

This study explores the effects of active hip extension moment produced by electrical stimulation on the support forces the arms must exert through an assistive device during quiet erect standing with functional neuromuscular stimulation (FNS) in individuals with spinal cord injuries (SCI). A static sagittal plane biomechanical model of human standing was developed to predict the effects of stimulated hip extension moment and sagittal plane hip angle on the arm support necessary to maintain an upright posture. Two individuals with complete thoracic SCI were then tested while they stood with continuous stimulation to the knee and trunk extensors. The steady-state active extension moment exerted at the hip was varied by activating different combinations of hip extensor muscles with continuous stimulation while steady-state support forces applied to the arms and feet during standing were measured. The steady-state support forces imposed on the arms during quiet standing decrease with increased stimulated hip extension moment and are highly dependent upon hip flexion angle, as predicted by the biomechanical simulations. Experimentally, the combination of gluteus maximus and semimembranosus stimulation produced three times more steady-state hip extension moment than did stimulation of the gluteus maximus and adductor magnus. This resulted in a ten-fold decrease in body weight supported on the arms. More vertical postures (smaller hip flexion angles) improve the effectiveness of the hip extensor muscles in reducing the support forces placed on the arms. A single Newton-meter of stimulated hip extension moment with the hips fixed at 5 degrees of flexion results in almost five times the reduction in arm support forces as with the hips at 20 degrees. To minimize the forces applied by the arms on an assistive device for support while standing with FNS, these preliminary results suggest that (1) efforts should be made to assume the most erect postures possible and (2) muscles and stimulation paradigms that maximize active hip extension moment should be chosen.     

离心运动训练对髌股疼痛综合征患者膝关节功能和神经肌肉控制的效果

目的 探讨离心运动训练对髌股疼痛综合征患者膝关节功能及神经肌肉控制的影响。方法 2016年9月至2019年9月,本院门诊髌股疼痛综合征患者39例,随机分为对照组(n = 19)和试验组(n = 20)。两组均接受常规康复训练,试验组加用股四头肌离心运动训练,共8周。治疗前后采用疼痛视觉模拟评分(VAS)、膝关节Lysholm评分进行评定,采用等速测试与训练系统测量加速时间,平衡测试仪测量稳定指数。结果 治疗后,两组VAS评分,各肌肉加速时间,总体、左右和前后稳定指数均降低(t > 2.521, P < 0.05),Lysholm评分显著提高(|t| > 13.628, P < 0.001)。试验组VAS评分、各肌肉加速时间、总体及前后稳定指数低于对照组(|t| > 2.174, P < 0.05),Lysholm评分显著高于对照组(t = 11.947, P < 0.001)。结论 股四头肌离心运动训练可缓解髌股疼痛综合征患者膝关节疼痛,提高膝关节功能和神经肌肉控制能力。     

Impact of decline-board squat exercises and knee joint angles on the muscle activity of the lower limbs

[Purpose] This study aims to investigate how squat exercises on a decline board and how the knee joint angles affect the muscle activity of the lower limbs. [Subjects] The subjects were 26 normal adults. [Methods] A Tumble Forms wedge device was used as the decline board, and the knee joint angles were measured with a goniometer. To examine the muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior of the lower limbs, a comparison analysis with electromyography was conducted. [Results] The muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior increased with increased knee joint angles, both for squat exercises on the decline board and on a flat floor. When the knee joint angle was 45°, 60°, and 90°, the muscle activity of the rectus femoris was significantly higher and that of the tibialis anterior was significantly lower during squat exercises on the decline board than on the flat floor. When the knee joint angle was 90°, the muscle activity of the gastrocnemius lateralis was significantly lower. [Conclusion] Squat exercises on a decline board are an effective intervention to increase the muscle activity of the rectus femoris with increased knee joint angles.Key words: Decline board, Squat exercise, Range of motion     

Restoring normal gait after limb salvage procedures in malignant bone tumours of the knee.

Eleven patients exhibiting decreased strength of knee extension following wide resection and prosthetic reconstruction for malignant bone tumors of the knee performed gait exercises with compensatory muscle training. Two patients whose knee extension strength was assessed as manual muscle test (MMT) grade 4 were able to develop a gait with double knee action and to maneuver stairs, step-by-step, due to compensation by the gluteus maximus, biceps femoris, and gastrocnemius muscles. Four patients whose knee extension strength was less than MMT grade 4, and whose ankle dorsal and plantar flexion was MMT grade 4 or higher, acquired the ability to go up and down stairs step-by-step, although their gait pattern was a knee-extended gait. Electromyographic studies demonstrated continuous discharges of the gluteus maximus, biceps femoris, and gastrocnemius muscles during the stance phase as compensation for decreased strength in knee extension.     

The effects of axial and multi-plane loading of the extensor mechanism on the patellofemoral joint

Objective. To compare the effects of axial loading, and anatomically based multi-plane loading of the extensor mechanism on the patellofemoral joint.

Design. Repeated measures design using an in-vitro cadaver model.

Background. Since the extensor mechanism is the primary contributor to the patellofemoral joint reaction force and can affect patellar kinematics, it is essential that the forces produced by this musculature be accurately represented in a simulation model.

Methods. Patellar kinematics (magnetic tracking device), contact pressures and areas (pressure sensitive film) were measured from 6 cadaver knees under two different loading conditions: 1) axial (rectus femoris loaded in the frontal plane), and 2) multiplane (individual components of the quadriceps loaded along their respective fiber directions in both the frontal and sagittal planes). Specimens were mounted in a custom knee jig, with muscle forces being simulated using a pulley system and weights. Data were collected at 0 °, 15 °, 30 °, 45 °, 60 °, 75 ° and 90 ° of knee flexion.

Results. Compared to the axial loading condition, multi-plane loading of the vasti resulted in significantly greater contact pressure at 0 ° and significantly less contact pressure at 90 ° of knee flexion. Furthermore, the multi-plane loading condition resulted in greater lateral patellar rotation from 0–75 ° of knee flexion, and greater lateral glide at 30 ° of knee flexion. Greater patellar flexion was observed with the axial loading condition.

Conclusions. These findings indicate that axial loading of the extensor mechanism underestimates contact pressure at 0 ° and overestimates contact pressure at 90 ° of knee flexion when compared to multi-plane loading. Additionally, loading of the individual vasti appears to have an effect on patellar kinematics.     

Comparison of the prevalence of myofascial trigger points of muscles acting on knee between patients with moderate degree of knee osteoarthritis and healthy matched people

IntroductionTrigger points have been implicated in the development of several musculoskeletal disorders. Trigger points harbored in lower limb muscles might represent a ubiquitous source of pain in patients with knee osteoarthritis (OA). This study was carried out to evaluate the prevalence of Myofascial Trigger Points (MTrPs) in muscles acting on the knee in patients with OA.MethodsThirty-seven patients aged at least 55 years old with a moderate degree of OA (grade III of Kellgren and Lawrence scale) were recruited. Thirty asymptomatic people, matched on age and body mass index, were considered as the control group. Ten muscles acting on the knee joint were selected. Taut bands were also identified using a skin rolling method. A pressure of 3 kg/cm² was used to identify myofascial trigger points in all muscles except the popliteus (8 kg/cm²).ResultsChi-square was performed to compare the prevalence of trigger points between the groups. The McNemar test was administered to compare the prevalence of trigger points in the right and left sides of participants. Prevalence of the trigger points was significantly higher in patients with knee OA compared with asymptomatic people in all muscles except for right (p = 0.17) and left (p = 0.41) rectus femoris, right (p = 0.61) and left (p = 0.22) sartorius and left biceps femoris (p = 0.08). Comparison of the prevalence of MTrPs bilaterally revealed that only the right and left sartorius differed significantly (p = 0.008).ConclusionsThe prevalence of MTrPs in the muscles acting on the knee joint is higher in patients with a moderate degree of knee OA compared with asymptomatic subjects.     

腓骨头复合组织瓣切取后膝关节生物力学的稳定性

背景:股二头肌腱和外侧副韧带是膝关节后外侧复合体的重要组成成分,对维持膝关节后外侧稳定性有重要意义。目的:观察腓骨头复合组织瓣切取后供区股二头肌腱和外侧副韧带下止点重建对膝关节稳定性的影响。方法:选择10例男性新鲜冷冻膝关节尸体标本,利用生物力学扭转试验机测量腓骨头复合组织瓣切取前及股二头肌腱和外侧副韧带下止点重建后不同转矩下的胫骨外旋角。结果与结论:同一转矩条件下,胫骨外旋角随膝关节屈曲角度的增大而变大,腓骨头复合组织瓣切取前及股二头肌腱和外侧副韧带下止点重建后比较差异无显著性意义;不同外旋转距条件下,外旋角变化的趋势一致。提示腓骨头复合组织瓣切取后,妥善重建股二头肌腱和外侧副韧带下止点,不会对膝关节稳定性造成显著影响。     

Activity of the Femoral Muscles during Toe-gripping Action

[Purpose] In the present study, we investigated femoral muscle activity during toe-gripping, and the role of the femoral muscles in toe-gripping strength. [Subjects] Fourteen healthy young women were selected. [Methods] We measured the maximum voluntary contraction of the rectus femoris and long head of the biceps femoris muscles. We then calculated the percent integrated EMG (%IEMG) during the toe-gripping action. [Results] We found that the %IEMG of the biceps femoris was significantly higher than that of the rectus femoris. Moreover, a significant positive correlation was found between the %IEMG of the rectus femoris and that of the biceps femoris. [Conclusion] These results suggest that femoral muscles co-contract during the toe-gripping action, and thus possibly contribute to knee joint stability.     

不同干预方式对斜方肌在运动中激活模式的影响

目的 分析正常人斜方肌的激活特征,观察不同干预方式对斜方肌异常者激活模式恢复的作用。方法 2017年9月至10月,互联网招募肩关节正常人(正常组,n = 20)和肩关节不适者(观察组,n = 20),在无干预、上斜方肌(UT)静力牵拉、下斜方肌(LT)等长收缩和组合干预后,均完成直臂侧上举、坐姿划船和反向飞鸟动作。测试记录肌电信号的均方根值(RMS),计算最大自主收缩肌电百分比(MVE%),观察激活比例和激活时间。结果 无干预时,与对照组比较,观察组UT MVE%增加(P < 0.05),激活时间提前(P < 0.05);中斜方肌(MT)和LT MVE%降低(P < 0.05),激活时间延迟(P < 0.05);UT/LT和UT/MT增加(P < 0.05)。UT静力牵拉、LT等长收缩和组合训练后,两组不同肌肉MVE%、激活时间、激活比例在不同动作下均有不同程度改变(P < 0.05)。结论 斜方肌三束在不同动作中,激活程度与激活时间不同;在运动开始前进行UT静力牵拉和LT等长收缩可以改善肩关节不适者的斜方肌在运动中的激活模式,有利于肩关节发挥正常功能。