骨骼肌最大收缩力与最适初长度及其参数的研究

本实验以免载体股直肌为实验模型,研究了该肌在一定脉冲电流刺激下其初长度与收缩力、肌张力及肌力变化的相互关系。同时测定了正常生理状态下兔伸屈膝时股直肌拉长度的变化。结果表明:兔股直肌延长在1.0cm内时,肌力随初长度的延长而增大,超过1.0cm时增大已不明显(p<0.0 1),1.0cm与股直肌的生理最大延长度1.1cm相似。说明兔股直肌的初长度变化不应超过生理最大延长度。而人的骨骼肌与哺乳动物的骨骼肌没有本质的区别,因此,人骨骼肌的初长度变化也不应超过生理最大延长度。肌腱转位后的活动范围应在原位的生理活动范围内,才能发挥最佳收缩效应。     

Distal rectus femoris surgery in children with cerebral palsy: results of a Delphi consensus project

PurposeThe purpose of this study was for an international panel of experts to establish consensus indications for distal rectus femoris surgery in children with cerebral palsy (CP) using a modified Delphi method.MethodsThe panel used a five-level Likert scale to record agreement or disagreement with 33 statements regarding distal rectus femoris surgery. The panel responded to statements regarding general characteristics, clinical indications, computerized gait data, intraoperative techniques and outcome measures. Consensus was defined as at least 80% of responses being in the highest or lowest two of the five Likert ratings, and general agreement as 60% to 79% falling into the highest or lowest two ratings. There was no agreement if neither threshold was reached.ResultsConsensus or general agreement was reached for 17 of 33 statements (52%). There was general consensus that distal rectus femoris surgery is better for stiff knee gait than is proximal rectus femoris release. There was no consensus about whether the results of distal rectus femoris release were comparable to those following distal rectus femoris transfer. Gross Motor Function Classification System (GMFCS) level was an important factor for the panel, with the best outcomes expected in children functioning at GMFCS levels I and II. The panel also reached consensus that they do distal rectus femoris surgery less frequently than earlier in their careers, in large part reflecting the narrowing of indications for this surgery over the last decade.ConclusionThis study can help paediatric orthopaedic surgeons optimize decision-making for, and outcomes of, distal rectus femoris surgery in children with CP.Level of evidenceV     

Functionally complex muscles of the cat hindlimb

The biceps femoris (BF) muscle is divided into three neuromuscular compartments defined by the innervation patterns of the main nerve branches (English and Weeks 1987). The goals of this study were i) to determine how different regions of the biceps femoris muscle are activated in the intact cat during a broad range of limb movements evoked by perturbations of stance posture, and ii) to determine the relationship between the anatomical compartments of biceps femoris and the functional units as defined in this task. Cats were trained to stand on a moveable platform with each paw on a triaxial force plate. The animal's stance was perturbed by linear translation of the platform in each of sixteen different directions in the horizontal plane. EMG activity was recorded from eight sites across the width of the left biceps femoris muscle. During quiet stance only the anterior compartment was tonically active, presumably contributing to hip extensor torque in the maintenance of stance. During platform translation, evoked EMG activity was recorded from each electrode pair for a wide range of directions of perturbation; as direction changed progressively, the amplitude of evoked activity from any electrode pair increased to a maximum and then decreased. When the EMG amplitude was plotted in polar coordinates as a function of translation direction, the region of response formed a petal shaped area in the horizontal plane, termed the EMG tuning curve. The compartments of the BF muscle were not activated homogeneously. The tuning curve of the anterior BF compartment was similar to that of other hip extensors, and coincided with the region of postero-lateral force production by the hindlimb against the support. The tuning curve of the middle BF compartment was shifted in a counterclockwise direction from that of the anterior compartment, but overlapped extensively with it; the middle BF tuning curve was similar to that of anterior gracilis. The tuning curve of the posterior biceps compartment was rotated further counterclockwise and overlapped very little with that of the middle BF compartment. The posterior BF was activated in a pattern similar to that of other knee flexors. The functional units of BF activation were not identical with the neuromuscular compartments defined by the main nerve branches. As direction of the perturbation changed, the region of BF that was activated moved progressively across the muscle. This progression of the active region was continuous across BFa and BFm, whereas there was a jump, or discontinuity at the border between BFm and BFp.(ABSTRACT TRUNCATED AT 400 WORDS)     

带血管蒂阔筋膜张肌及腱膜转位修补巨型腹股沟疝的应用解剖

目的:为带血管蒂阔筋膜张肌及腱膜转位修补巨型腹股沟疝提供解剖学基础。方法:在30例成人下肢标本上解剖观测了阔筋膜张肌的动脉血管分布,神经支配,肌腹和肌腱的长度等。结果:阔筋膜张肌动脉来源有旋股外侧动脉和臀上动脉,该肌由臀上神经支配,肌腹长度为112.31±3.13mm,髂经束的长度为315±6.8mm,额前上棘水平至腹肌外侧缘的距离,男性为168±7.5mm,女性为176±6.8mm。结论:阔筋膜张肌血供丰富,肌腱膜长,位置邻近腹股沟区,可作为巨型腹股沟疝修补的供体。     

Dietary Restriction Reduces the Prevalence of Osteonecrosis of the Caput Femoris in Spontaneously Hypertensive Rats

We investigated the effects of dietary restriction (DR), an experimental intervention known to suppress several strain-specific diseases, on the prevalence of osteonecrosis of the caput femoris in spontaneously hypertensive rats (SHR). At 6 weeks of age, the food intake of DR rats was restricted to 65% of the mean intake of control rats fed ad libitum (AL). Acute osteonecrosis of the caput femoris without reparative tissue response (RTR) was observed at 10 and 15 weeks in both DR and AL groups; no such acute lesion was seen at 20 and 30 weeks. The prevalence of osteonecrosis, osteonecrosis with/without reparative tissue response was significantly reduced in DR rats at 15 and 20 weeks, but not at 10 weeks. DR reduced the body weight by 30% and the length of the femur by 10%. Ossification of the caput femoris, known to be delayed in AL rats compared with Wistar Kyoto rats, was also restored by DR. Our results showed that dietary restriction reduced the prevalence of osteonecrosis and modulated the mechanical factors involved in the lesion. They also indicate that utilization of dietary restriction is a useful research tool for investigating the underlying mechanisms of osteonecrosis of the caput femoris in SHR. Received: 4 March 1997 / Accepted: 9 July 1998     

Erdheim-Chester disease with intramuscular lipogranuloma

We report on a rare manifestation of Erdheim-Chester disease with intramuscular lipogranuloma. The patient was a 66-year-old man who noted a soft tissue mass in the right quadriceps femoris muscle. Radiographs revealed symmetrical osteosclerosis in the diametaphysis of both femora and tibiae. An open biopsy revealed a proliferation of lipid-laden histiocytes in the femoral bone marrow and the quadriceps femoris muscle. To our knowledge, this is the second case of Erdheim-Chester disease involving muscle. Received: 4 October 1999 Revision requested: 18 November 1999 Revision received: 1 December 1999 Accepted: 2 December 1999     

Application of Shear-Wave Elastography in the Evaluation of Hamstring Stiffness in Young Basketball Athletes

BackgroundPrevious literature has postulated a relationship between greater hamstring stiffness and a higher risk of sustaining injury. Shear wave elastography (SWE) presents a relatively new means for non-invasive evaluation of soft tissue elasticity pre- and post- injury or intervention.Purpose1. To establish baseline hamstring stiffness measures for young competitive athletes and (2) determine effect of targeted neuromuscular training (TNMT) on shear wave stiffness of the hamstring.Study DesignUn-blinded, prospective, non-randomized, cohort study.MethodsSix-hundred forty-two lower extremities from 321 high school and collegiate basketball athletes (177 F: 139 M) were examined for hamstring stiffness prior to the start of their competitive basketball season. Teams were cluster assigned to either the control or intervention (TNMT) group. Subjects in the control group underwent regular season activities as directed, with no influence from the research team. For the TNMT group, the research team introduced a hamstring targeted dynamic warm-up program as an intervention focused on activating the hamstring musculature.ResultsCollegiate status was significant to hamstring stiffness for both sexes (p ≤ 0.02), but hamstring stiffness did not correlate to age or sex (r² ≤ 0.08). Intervention was a significant factor to hamstring stiffness when the hip was positioned in extension (p ≤ 0.01), but not in deeper flexion (p = 0.12). This effect was sex-specific as TNMT influenced hamstring stiffness in females (p = 0.03), but not in males (p ≥ 0.13). Control athletes suffered three HAM injuries; TNMT athletes suffered 0 hamstring injuries.ConclusionHigher SWE measurements correlated with increased risk of injury, male sex, and collegiate athletics. TNMT intervention can lessen muscle stiffness which may reduce relate to injury incidence. Intervention effectiveness may be sex specific.Level of EvidenceII     

Prevalence,frontal plane knee alignment,and lower limb joint pain and injury in generalized joint hypermobility in Thai physical therapy students

ObjectivesThe primary aim was to study the prevalence of generalized joint hypermobility (GJH) among Thai physical therapy (PT) students. The secondary aims were to compare the lower limb alignments and lower limb joint pain and injury between GJH and non-GJH individuals. Furthermore, the association between GJH, lower limb alignment, and joint pain and injury were also evaluated.Material and methodsGeneralized joint hypermobility was assessed using the Beighton score with a cut-off of 4/9 in 255 PT students. The lower limb alignments measured in the study included pelvic tilt angle, tibiofemoral angle, quadriceps angle (QA), and navicular drop. Tibiofemoral angle and QA were measured with and without quadriceps contraction. The history of lower limb joint pain and injury was recorded with a simple questionnaire. Lastly, logistic regression analysis was used to study the association between GJH, lower limb alignment, and joint pain and injury.ResultsThe prevalence of GJH was 21.18% among the studied population. Quadriceps angle during quadriceps relaxation of the non-dominant leg of the GJH group was the only lower limb alignment found greater than those of the non-GJH group. The rate of lower limb joint pain and injury was not different between the two groups. Furthermore, no significant association between GJH, lower limb alignment, and lower limb joint pain and injury was found.ConclusionsGJH is not uncommon among Thai PT students. Only the non-dominant QA was found different between groups. Generalized joint hypermobility neither increase risk nor is it associated with lower limb joint pain and injury among Thai PT students.     

Effects of Adenosine Triphosphate (ATP) on Early Recovery After Total Knee Arthroplasty (TKA): A Randomized,Double-Blind,Controlled Study

Functional exercise after total knee arthroplasty (TKA) is necessary. However, it may be a difficult and painful process for the patient. Desirable methods of relieving the patient's pain are worth exploring. Oral supplement of adenosine triphosphate (ATP) is a potential option. In the present study, we decide to investigate whether short-term administration of ATP benefits patients undergoing TKA. A total of 244 subjects were randomized to receive 120 mg ATP or placebo each day for 4 weeks. Significant differences in quadriceps strength, pain scores at postoperative days 7, 14, 21, and 28 and total opioid consumption were detected. It follows that oral supplement of ATP could benefit patients recovering from TKA.     

Anatomical Variations of the Profunda Femoris Artery and Its Branches—A Cadaveric Study in South Indian Population

The variations of the profunda and its branches are numerous, and, to a considerable extent, largely associated with one another. In occlusion of the Superficial femoral artery, the profunda femoris artery forms an effective collateral bed between the ileo-femoral segment and the popliteal artery and its branches. This study based on dissections performed on 40 properly embalmed human cadaver specimens. The position, source and the point of origin of the profunda and its circumflex branches were studied and compared with earlier literature. We found that profunda femoris was originated from the posterolateral surface of the common femoral artery with a mean distance of 3.56 cms from the midinguinal point. An absence of profunda femoris was noted in one (5 %) case. Medial circumflex femoral artery (in 40 % on right side and 60 % on left side) originated from the profunda femoris; whereas in 50 % on right and 35 % on left side, it begins from the femoral artery. On the otherhand, the lateral circumflex femoral in 80 % on right and 70 % on left sides sprungs from profunda femoris with 20 % and 25 % from common femoral arteries of right and left limb specimens respectively. Knowledge of variations in profunda femoris and its branches helps surgeons during preoperative clinical evaluation for surgical and interventional revascularization of the ileo-femoral and femoro-popliteal segments, in open canulation of femoral artery for cardiopulmonary bypasss, in radiological interventions for A-V malformations, and in salvage operations for traumatic limb ischemia.