Length and moment arm of human leg muscles as a function of knee and hip-joint angles

Summary Lengths of muscle tendon complexes of the quadriceps femoris muscle and some of its heads, biceps femoris and gastrocnemius muscles, were measured for six limbs of human cadavers as a function of knee and hip-joint angles. Length-angle curves were fitted using second degree polynomials. Using these polynomials the relationships between knee and hip-joint angles and moment arms were calculated. The effect of changing the hip angle on the biceps femoris muscle length is much larger than that of changing the knee angle. For the rectus femoris muscle the reverse was found. The moment arm of the biceps femoris muscle was found to remain constant throughout the whole range of knee flexion as was the case for the medial part of the vastus medialis muscle. Changes in the length of the lateral part of the vastus medialis muscle as well as the medial part of the vastus lateralis muscle are very similar to those of vastus intermedius muscle to which they are adjacent, while those changes in the length of the medial part of the vastus medialis muscle and the lateral part of the vastus lateralis muscle, which are similar to each other, differ substantially from those of the vastus intermedius muscle. Application of the results to jumping showed that bi-articular rectus femoris and biceps femoris muscles, which are antagonists, both contract eccentrically early in the push off phase and concentrically in last part of this phase.     

Effect of maximal arm exercise on skin blood flux in the paralyzed lower limbs in persons with spinal cord injury

 The purpose of the present study was to examine the effect of maximal arm exercise on the skin blood circulation of the paralyzed lower limbs in persons with spinal cord injury (PSCI). Eight male PSCI with complete lesions located between T3 and L1 performed graded maximal arm-cranking exercise (MACE) to exhaustion. The skin blood flux at the thigh (SBFT) and that at the calf (SBFC) were monitored using laser-Doppler flowmeter at rest and for 15 s immediately after the MACE. The subject's mean peak oxygen uptake and peak heart rate was 1.41 ± 0.22 l · min^–1 and 171.6 ± 19.2 beats · min^–1, respectively. No PSCI showed any increase in either SBFT or SBFC after the MACE, when compared with the values at rest. These results suggest that the blood circulation of the skin in the paralyzed lower limbs in PSCI is unaffected by the MACE. Accepted: 12 September 1996     

Developmental regulation of type 1 and type 3 interferon production and risk for infant infections and asthma development

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National Athletic Trainers' Association Position Statement: Head-Down Contact and Spearing in Tackle Football

OBJECTIVE: To present recommendations that decrease the risk of cervical spine fractures and dislocations in football players. BACKGROUND: Axial loading of the cervical spine resulting from head-down contact is the primary cause of spinal cord injuries. Keeping the head up and initiating contact with the shoulder or chest decreases the risk of these injuries. The 1976 rule changes resulted in a dramatic decrease in catastrophic cervical spine injuries. However, the helmet-contact rules are rarely enforced and head-down contact still occurs frequently. Our recommendations are directed toward decreasing the incidence of head-down contact. RECOMMENDATIONS: Educate players, coaches, and officials that unintentional and intentional head-down contact can result in catastrophic injuries. Increase the time tacklers, ball carriers, and blockers spend practicing correct contact techniques. Improve the enforcement and understanding of the existing helmet-contact penalties.     

Retroesophageal right subclavian artery with persistent ductus arteriosus

We report an adult male cadaver with persistence of the ductus arteriosus and a right retroesophageal artery. The retroesophageal artery was first appreciated as a retropharyngeal mass during the dissection of this area. Both the left and right vertebral arteries originated in normal fashion. The thoracic duct of our specimen drained into the junction of the left internal jugular and left subclavian veins. We believe this to be the first report of simultaneous right retroesophageal subclavian artery and patent ductus arteriosus. The anatomy and embryology of these two anomalies in the same specimen are discussed.     

面神经电图与瞬目反射在Bell麻痹中的应用比较

目的：比较面神经电图（ENoG)与瞬目反射（BR）在Bell麻痹中的应用价值。方法：50例Bell麻痹患者在发病后1－3天（A组）和8－14天（B组）分别作面神经EnoG与BR检查。结果：BR在1－3天患侧就表现出明显异常，但1－3天及8－14天检查无明显差异。面神经ENoG在8－14天才表现明显异常。结论：对于Bell麻痹患者早期诊断作BR优于面神经ENoG，面神经ENoG在发病后8－14天对预后评价优于BR。     

Application of the medical anti-shock trouser (MAST) increases cardiac output and tissue perfusion in simulated,mild hypovolaemia

We have studied the haemodynamic effects of the application of the medical anti-shock trouser (MAST) in 10 healthy subjects in the semi-upright position in order to simulate mild hypovolaemia. Left ventricular end diastolic dimension (EDD) was measured by M-mode echocardiography and cardiac output (CO) by the Doppler ultrasound technique. Forearm blood flow (FBF) was measured by plethysmography and blood pressure (BP) by the standard cuff technique. Systematic increases in MAST pressure of up to 80 mm Hg were applied. EDD increased to a maximum of 9.3% (p0.01) which was associated with a maximum increase in CO of 31.7% (p0.05). FBF increased by a maximum of 54.2% (p0.001) whilst BP increased by a maximum of 12% (p0.001). These results demonstrate that the application of the MAST is an effective means of transferring blood to the central circulation by compression of the capacitance vessels resulting in significant increases in cardiac output and tissue perfusion. At high pressures there was evidence of compression of resistance vessels, which may be useful in reducing blood loss. The ease and rapidity with which his suit can be applied suggests that it may be useful in the short term treatment of hypovolaemia.     

互动式头针结合镜像疗法对脑卒中软瘫期上肢功能障碍的康复疗效

目的：探索脑卒中患者促进上肢运动功能恢复中头针与镜像疗法联合应用的临床价值。方法：选取株洲市中心医院2021年8月至2022年11月期间收治的60例脑卒中后上肢功能障碍患者,以随机分组的方式分为两组,每组30例。其中常规康复训练联合镜像治疗纳入对照组,在对照组基础上增加头针治疗纳入观察组。在治疗4周后,比较两组患者临床治疗有效性、Fugl–meyer运动功能评定量表（FMA）上肢部分评分以及Brunnstrom分期。结果：两组患者治疗后FMA评分均高于治疗前,且观察组患者治疗后FMA评分高于对照组,差异具有统计学意义（P<0.05）。观察组患者治疗后上肢Brunnstrom运动功能分期结果优于对照组,差异具有统计学意义（Z=–2.101,P <0.05）。观察组患者治疗后手Brunnstrom运动功能分期结果优于对照组,差异具有统计学意义（Z=–2.152,P <0.05）。结论：在恢复早期,头针、镜像疗法与常规康复训练有效结合,对脑卒中患者软瘫期上肢运动功能恢复具有积极作用。     

体外膈肌起搏器在治疗面神经麻痹中的临床应用

目的 :探讨体外膈肌起搏器配合药物治疗特发性面神经麻痹的疗效。方法 :治疗组在常规使用激素、血管扩张剂和神经营养药等治疗的基础上配合应用体外膈肌起搏器 ,治疗面神经麻痹 ,对照组单纯使用药物治疗 ,对照两组的治愈率、好转率和平均治疗时间和好转时间。结果 :治疗组 73例 ,治愈 6 2例 ,好转 5例 ,总有效率 92 % ;对照组 32例 ,治愈 2 3例 ,好转 5例 ,总有效率 81% ,两组差异有显著性。 (P <0 0 5)。结论 :应用体外膈肌起搏器配合药物治疗面神经麻痹治愈率高 ,疗程缩短