Passive properties of the forearm musculature with reference to hand and finger postures

OBJECTIVE: To quantify individual forearm muscle passive forces and evaluate their impact on hand function. DESIGN: The passive force-length properties of the 24 extrinsic hand and wrist muscles were determined in five fresh frozen cadaver arms. BACKGROUND: Muscle force production is a summation of the active and passive force components. The passive properties of the extrinsic finger musculature and wrist musculature appear to strongly affect both hand posture and hand movement. METHODS: The passive force-length properties of extrinsic hand and wrist muscles were determined by applying a slow, continuous extension to each muscle and recording the resulting tension. Each force-length curve was fit using exponential regression and were related to specific joint rotations and seven hand postures by calculating the muscle excursions for those postures. RESULTS: The exponential passive force-length relationship explained over 97% of the experimental variance. The largest passive forces were elicited in the digital extensors in grips involving large flexion angles such as tip pinch, key pinch, and a briefcase grip. CONCLUSIONS: The passive properties of the extrinsic finger musculature and wrist musculature affect both hand posture and movement especially in postures with flexed wrist and fingers.     

Effect of a back belt on reaching postures

OBJECTIVE: The present study investigated the effect of a back belt on reach actions. SUBJECTS: Sixteen undergraduate college students (8 male students, 8 female students) ranging in age from 18 to 22 years. Thirteen subjects were included in the final analysis. SETTING: The Department of Psychology at Miami University, Oxford, Ohio METHODS: Using a well-established set of procedures developed in our laboratory for studying reaching, seated adult participants reached for and retrieved an object placed at various distances from them. Reach distances included values both closer than and farther than each subject's maximum seated reach. The reach task had 2 conditions: picking up and retrieving a small block and skewering and retrieving a small bead with a needle. For each task condition, each subject either wore the belt or did not use a belt. RESULTS: Results indicate that when subjects wore the belt while reaching, they tended to have initial transition points (sitting to nonsitting) closer to their bodies than while not wearing the belt. That is, for a distant object, subjects were more likely to raise their bodies out of the chair rather than perform an extreme seated reach, possibly acting to preserve a greater margin of safety. CONCLUSIONS: The back belt consistently modified reaching postures by limiting extreme ranges of motion during a task that required enhanced stability. Furthermore, the methodology and analysis presented in this article when applied to chiropractic will allow us to begin thoughtful investigation of the effects of chiropractic adjustments on postural transitions and margin of safety.     

Multi-directional strength and force envelope of the index finger

Objective. The purpose of this study was to biomechanically evaluate the motor function of the index finger based on multi-directional strengths.

Design. An experimental apparatus was developed to measure force production of a digit at various points of force application along the digit and in any direction of force application within the transverse plane of the longitudinal axis of the digit.

Background. Most existing tests of hand motor function are subjective, semiquantitative, and/or non-specific.

Methods. Eight normal subjects with asymptomatic hands were tested. Maximum voluntary isometric contraction forces were measured at the middle of the proximal phalanx of the index finger in 16 directions that were evenly distributed within 360°.

Results. The highest force, 110.7 (SD 9.0) N, was generated in flexion, while the lowest force was generated in extension. The forces in extension, abduction and adduction were 37.6%, 97.9% and 79.3% of the flexion force, respectively. The area of the force envelope was 25 739 (SD 3688) N–N. The average percentage quadrant areas, relative to the total force envelope area, for extension–adduction, extension–abduction, flexion–abduction, and flexion–adduction were 12.9%, 20.4%, 36.0%, and 30.8%, respectively. The average percentage quadrant areas for extension, abduction, flexion, and adduction were 9.1%, 33.3%, 35.6%, and 22.1%, respectively.

Conclusion. The current study provides an advanced level of quantification of hand motor function.Relevance

The methods may be used as a basis to detect changes in the motor function resulting from pathological conditions, disease progression, as well as rehabilitation and treatment of these disorders.     

康复指导对断指再植术后患指功能恢复的影响

目的 探讨康复干预对断指再植术后患指功能的效果.方法 对178例断指再植患者按入院时间顺序分为康复组90例和对照组88例.两组均行常规护理.康复组则给予康复指导.结果 康复组患指成活率明显提高(P<0.01),患指功能恢复良好(P<0.01).结论 康复指导有助于患指功能的恢复,提高断指再植成活率.     

地佐辛对断指再植术后患者断指成活率及VAS评分的影响

目的 探讨地佐辛对断指再植术后患者断指成活率及VAS评分的影响.方法 选取我院收治的100例断指再植术患者为研究对象,按随机数字表将其分为对照组和观察组,各50例.对照组给予氟哌利多+托烷司琼治疗,观察组给予地佐辛+托烷司琼治疗.比较两组的镇痛效果.结果 观察组术后3个月的断指再植成活率高于对照组(P<0.05);观察...     

Effect of different arm loads on the position of the scapula in abduction postures.

OBJECTIVE: The objective of this study is to determine the relation between arm load and the three-dimensional shoulder orientations. BACKGROUND: Analysis of a musculo-skeletal system by means of an inverse dynamical simulation requires postural data of the bony elements involved. For the shoulder, the positions of the clavicle and the scapula are difficult to record due to the skin displacement. It would therefore be useful to predict the three-dimensional relation between the orientation of the arm, the clavicula and the scapula, i.e. the three-dimensional shoulder rhythm, with respect to the thorax under different load conditions. METHODS: The orientation of the clavicula and the scapula was determined with respect to the thorax by means of palpation of skeletal landmarks, for seven postures of arm elevation in the frontal plane at four load conditions: 0, 0.9, 1.9 and 2.9 kg at the wrist. The data were expressed by Cardan angles and analyzed by means of repeated measurements analysis of variance. RESULTS: While the clavicular and scapular angles were significantly related to the arm elevation, no significant relation was found with the load in the hands for the seven arm postures. CONCLUSIONS: The three-dimensional shoulder rhythm does not change under different gravitational load conditions on the arm. RELEVANCE: The fact that the magnitude of the load does not affect the shoulder postures, i.e. the moment arms of the muscles, facilitates the biomechanical, ergonomical and clinical studies on the shoulder by the reduction on the number of recordings for equal task under different load conditions, and easy imitation of real life tasks in the laboratory.     

虚拟微创心脏手术中力觉信息的采集

利用等强度梁和步进电机模拟真实手术中的穿透过程,针对心脏瓣膜微创手术进行了不同穿透速度的力采集实验,获得了虚拟手术中力反馈的真实信息,也为建立虚拟人手术专家系统提供了有效的数据.实验记录了穿透曲线,发现当穿透力高于10 mm/s时心脏瓣膜的穿透力出现了峰谷交替出现的曲线;而低于这个速度时候并无明显的峰谷区别.还有一个明显的现象,穿透力随着穿透速度的增加而增加.实验数据为力反馈设备提供了实际的反馈曲线,并可以用于计算试验软组织对象的材料特性,为计算机仿真模拟提供材料参数.     

Manual stretch: effect on finger movement control and force control in stroke subjects with spastic extrinsic finger flexor muscles

This study evaluated the effects of manual stretch of extrinsic finger flexor muscles on finger extension movement control and force control in 16 spastic hemiparetic subjects. These subjects were randomly divided into a control group and an experimental group. A group of able-bodied subjects also participated. A joint-movement tracking test (JMTT) quantified control of active finger extension movement at the metacarpophalangeal joint of the index finger within the available range of active movement, and a force tracking test (FTT) quantified control of isometric finger extension force at the same joint within the subject's available force range. Electromyographic activity was monitored in the extensor digitorum and flexor digitorum superficialis muscles during both tracking tests. Manual stretch was applied to the extrinsic finger flexor muscles of the experimental group between the pretest and posttest tracking tests. The JMTT performances of both control (p less than .025) and experimental (p less than .05) groups were significantly subnormal on the pretest as were FTT performances of controls (p less than .01) and study subjects (p less than .03). The JMTT improvement on posttest was significantly greater (p less than .05) in subjects than in controls. However, the change in FTT performance was not significantly different between the two groups. Manual stretch treatment, properly applied to extrinsic finger flexor muscles, is an effective method of temporarily improving the control of finger extension movement in spastic hemiparetic subjects.     

鞋跟高度对地面反力和鞋底压力中心的影响

目的：通过研究女性行走时地面反力和鞋底压力中心，探讨鞋跟高度对地面反力和鞋底压力中心的影响。方法：测量穿不同类型和不同鞋跟高度的受试者，在不同行走速度下地面反力的大小和鞋底压力中心，分析地面反力变化和鞋底压力中心轨迹。结果：自然步速下，垂直方向上地面反力峰峰值随鞋跟高度增加而增大；穿中高鞋的侧向反力的峰峰值最大，而前进方向上峰峰值最小。随鞋跟高度的增加，鞋底压力中心侧向的移动量明显增大。结论：鞋跟高度导致人体侧向移动量增大，不同鞋跟高度对地面反力产生不同的影响。     

Effect of cigarette smoking on reactive hyperaemia in the human finger

Summary. The effect elicited by cigarette smoking on the reactive hyperaemia that develops following release of arterial occlusion in human skin was investigated, and compared to the corresponding effects elicited by oral administration of indomethacin (an inhibitor of the prostaglandin-forming enzyme cyclo-oxygenase) or nicotine, or by smoking of nicotine-free cigarettes. Finger blood flow was determined in human volunteers, using venous occlusion plethysmography, in the basal state and after 5 min of arterial occlusion. All subjects were studied before and after they had smoked two tobacco cigarettes, two herbal (nicotine-free) cigarettes, or chewed a nicotine chewing gum. The determinations before and after tobacco smoking were repeated after administration of indomethacin. In separate series, the effects of smoking on heart rate and systemic blood pressure were recorded. The basal finger blood flow was significantly (P< 0·05) diminished following cigarette smoking, by about 35%, and so was the reactive hyperaemia (P<0·05), by about 55%. The reactive hyperaemia after administration of indomethacin in combination with cigarette smoking did not differ from that obtained after cigarette smoking alone. The reactive hyperaemia was not affected by oral administration of nicotine, or by smoking of two herbal cigarettes. Cigarette smoking elicited increases in heart rate and systemic blood pressure that were of similar magnitude before and after indomethacin. From these data, we conclude that cigarette smoking elicits an inhibitory effect on the reactive hyperaemia in the human finger. This effect is probably not caused by nicotine, and seems to act via blockade of the vascular relaxation normally mediated by locally formed cyclo-oxygenase products.     

Effect of different postures of the scapular girdle and arm on the pressure pain threshold in the infraspinatus muscle

BackgroundMechanosensitivity changes and trigger points in the infraspinatus muscle are associated with several painful conditions of the upper limb. The aim of this study was to assess the effect of different postures of the upper quadrant on the pressure pain threshold (PPT) of the infraspinatus muscle.MethodsThis was an observational, cross-sectional study. Fifty-four subjects with and without shoulder pain (Asymptomatic subjects = 27, mean age 26.9 ± 4.92 years, BMI 23.73 ± 3.87), (symptomatic subjects = 27, mean age 27.6 ± 3.68 years, BMI 24.35 ± 3.86) were evaluated with a pressure algometer on the infraspinatus muscle belly, in four different positions of the upper quadrant: rest position (P1), passive scapular retraction position (P2), cervical contralateral inclination position (P3), and suprascapular nerve provocation position (P4). The assessed side was randomly chosen and all measurements were taken in sitting position.ResultsNo differences were observed between groups. The within-group analysis showed differences for both factors: “Positions” (F = 69.91; p = 0.001) and the interaction “Positions^Group” (F = 3.36; p = 0.02). The pairwise post-hoc analysis showed differences for the retracted position (P2) compared to others P1 (p = 0.001), P3 (p = 0.001), and P4 (p = 0.001), with higher PPT results achieved on the retracted position. Differences between P4 vs. P1 (p = 0.03) were also observed, with higher values for P4.ConclusionPlacing the scapular girdle in a passive scapular retraction position significantly reduces the pressure sensitivity at the infraspinatus muscle. Physiotherapists can take into account these results when assessing and treating patients with upper quadrant pain syndromes.     

针刀治疗扳机指操作方法对手指掌侧面局部解剖结构损伤情况的研究

目的:解剖验证几种针刀治疗扳机指操作方法对手指掌侧面局部解剖结构的损伤情况的安全性,为针刀疗法安全应用提供解剖学依据。方法:在6具尸体标本上,模拟常用的针刀治疗扳机指的几种常用操作方法,于操作后解剖标本并观察针刀对手指掌侧面局部解剖结构的影响损伤情况。结果:这几种操作方法均可刺入或穿透指屈肌腱,更甚者,如将指屈肌腱从骨面上铲起,会伤及骨膜和腱系膜等结构。纵横疏拨有可能割伤,甚至切断指屈肌腱和指掌侧固有神经及血管。结论:目前临床常用的几种针刀治疗扳机指的操作方法均可能伤及指屈肌腱,甚至可能伤及腱系膜、骨膜、指掌侧固有神经和血管,操作者应熟悉局部解剖并应慎重操作。     

自我效能干预对断指再植患者自我管理行为的影响

目的:探讨自我效能干预对断指再植患者自我管理行为的影响.方法:将60例患者随机分为观察组和对照组各30例.对照组给予断指再植术后显微外科常规护理,包括肢体血运观察、禁止主动或被动吸烟、患肢制动等;观察组在常规护理基础上,运用自我效能理论对患者进行自我管理行为的干预,包括激励、社会支持、替代经验、目标设置、负性刺激回避.结果:两组患者干预前后自我效能和自我管理行为得分差值比较差异有统计学意义,且两组患者干预前后自我管理行为各项因子分差值比较差异有统计学意义(P＜0.05).结论:自我效能干预可以有效提高断指再植患者的自我管理行为,降低血管危象的发生率.     

Effect of different sitting postures on lung capacity, expiratory flow, and lumbar lordosis

OBJECTIVE: To investigate the effect of sitting posture on lung capacity and expiratory flow (LC-EF) and lumbar lordosis. DESIGN: Repeated measures on 1 group of subjects in 4 postures. SETTING: Laboratory. PARTICIPANTS: Seventy able-bodied volunteers. INTERVENTIONS: Postures were assumed randomly: normal, with full ischial support and flat lumbar support; slumped, with the pelvis positioned in the middle of seat while leaning against the backrest; against the back part of the seat without ischial support (WO-BPS), with partially removed ischial support and an enhanced lumbar support; and standing. MAIN OUTCOME MEASURES: For LC-EF, forced vital capacity, maximum forced expiratory flow, forced expiratory volume in 1 second, and peak expiratory flow; and lumbar lordosis. RESULTS: All LC-EF measures in standing were significantly superior to those in slumped and normal sitting, and 4 measures were significantly higher than in WO-BPS. In slumped sitting, LC-EF significantly decreased from that in normal sitting. WO-BPS sitting significantly increased 4 of the LC-EF measures from those in the normal sitting. Lumbar lordosis was the highest in standing and progressively decreased in WO-BPS, normal, and slumped sitting. CONCLUSIONS: Slumped sitting significantly decreased LC-EF and lumbar lordosis. Because it increases the lumbar lordosis and promotes LC-EF, the WO-BPS posture may be a better seating option for people sitting for a prolonged time.     

随访干预对再造手指术后功能恢复的影响

目的探讨随访干预对足趾移植再造手指功能恢复的影响。方法选择2007年1月～2010年6月本科室收治的98例足趾移植再造手指患者,选择其中通讯地址详细的52例患者为干预组,另外46例患者为对照组。对照组接受常规的功能锻炼指导,干预组在此基础上实施随访干预,比较两组患者术后3～6个月再造手指功能恢复的情况。结果术后3个月和6个月,干预组再造手指功能恢复优于对照组(均P<0.05)。结论对再造手指的患者出院后进行随访干预,针对患者每个阶段的康复内容进行指导,可提高患者功能锻炼的依从性,对促进再造手指功能恢复具有重要的临床意义。