Elbow Flexion Movements Research Articles

Maximizing Outcomes While Minimizing Morbidity: An Illustrated Case Review of Elbow Soft Tissue Reconstruction.

Background. Injuries to the elbow have led to consequences varying from significant limitation in function to loss of the entire upper limb. Soft tissue reconstruction with durable and pliable coverage balanced with the ability to mobilize the joint early to optimize rehabilitation outcomes is paramount. Methods. Methods of flap reconstruction have evolved from local and pedicled flaps to perforator-based flaps and free tissue transfer. Here we performed a review of 20 patients who have undergone flap reconstruction of the elbow at our institution. Discussion. 20 consecutive patients were identified and included in this study. Flap types include local (n = 5), regional pedicled (n = 7), and free (n = 8) flaps. The average size of defect was 138 cm2 (range 36–420 cm2). There were no flap failures in our series, and, at follow-up, the average range of movement of elbow flexion was 100°. Results. While the pedicled latissimus dorsi flap is the workhorse for elbow soft tissue coverage, advancements in microvascular knowledge and surgery have brought about great benefit, with the use of perforator flaps and free tissue transfer for wound coverage. Conclusion. We present here our case series on elbow reconstruction and an abbreviated algorithm on flap choice, highlighting our decision making process in the selection of safe flap choice for soft tissue elbow reconstruction.

Does load uncertainty affect adaptation to catch training?

Catching relies on anticipatory and compensatory control processes. Load uncertainty increases anticipatory and compensatory neuromotor effort in catching. This experiment tested the effect of load uncertainty in plyometric catch/throw training on elbow flexion reaction time (RT), movement time (MT) and peak torque, as well as the distribution of anticipatory and compensatory neuromotor effort in catching. We expected load uncertainty training to be superior to traditional training for improving elbow flexion MT and peak torque, as well as for reallocating neuromotor effort from compensatory to anticipatory control in catching. Three groups of men (mean age=21), load knowledge training (K) (n=14), load uncertainty training (U) (n=13) and control (C) (n=14), participated. Groups K and U trained threetimes/week for 6weeks using single-arm catch/throw exercises with 0.45-4.08kg balls. Sets involved 16 repetitions of four different ball masses presented randomly. Group K had knowledge of ball mass on every repetition, whereas group U never did. Change scores were analyzed using Kruskal-Wallis tests and follow-up Wilcoxon rank-sum tests. Group K improved both RT and MT (by 6.2 and 12%, respectively), whereas group U did not. Both groups K and U improved peak eccentric elbow flexion torque. Group K reallocated neuromotor effort from compensatory to anticipatory processes in the biceps, triceps and the all muscle average, whereas group U did so in the triceps only. In sum, plyometric catch/throw training caused a reallocation of neuromotor effort from compensatory to anticipatory control in catching. However, load uncertainty training did not amplify this effect and in fact appeared to inhibit the reallocation of neuromotor effort from compensatory to anticipatory control.

The role of biceps brachii and brachioradialis for the control of elbow flexion and extension movements

How do synergistic muscles interact, when their contraction aims at stabilizing and fine-tuning a movement, which is induced by the antagonistic muscle? The aim of the study was to analyze the interaction of biceps and brachioradialis during fine-tuning control tasks in comparison to load bearing ones. The surface electromyogram of biceps, brachioradialis and triceps were examined in 15 healthy subjects in dynamic flexion and extension movements with different combinations of contraction levels, joint angles and angular velocities. The measurements were conducted in two configurations, where the torque due to an external load opposes the rotational direction of the elbow flexion (load bearing tasks) or the elbow extension (fine-tuning tasks).Whereas during load bearing control tasks, similar muscular activation of biceps and brachioradialis was observed for all joint angles, angular velocities and external loads, during fine-tuning control tasks a significant difference of the muscular activation of both flexors was observed for 1kg, F(3.639,47.305)=2.864, p=0.037, and 5kg of external load, F(1.570,21.976)=6.834, p=0.008.The results confirm the synergistic muscular activation of both flexors during load bearing tasks, but suggest different control strategies for both flexors when they comprise a fine-tuning control task.

Stiff elbows: Our experience

Elbow stiffness is one of the difficult disorders because of its nature being vulnerable to contracture. The conservative treatment should be recommanded firstly, then the surgical intervention is indicated after the failure of conservative attempt. From 2010 to 2015, we have been treating 258 cases who suffered elbow stiffness in our center. The causes of stiff elbows included trauma, rheumatoid arthritis, burn, degenerative disease, and congenital malformations. We would like to share our cases and experiences with the peers worldwide, and we also will learn more from the communication. (1) Any surgical history is important, the details (including the incision, internal fixation, nerve intervention) would guide the plan of surgery. (2) An overall physical examination should be amphasized every time the patient comes to the office, including extension and flexion deficiency, rotation limited or not, stability, skin contracture, and nerve symptoms. All these could become a puzzle during operation. (3) Radiography assessment (X ray, CT scan, MRI) aims to address the heterotrophic ossification, malunion, joint space, and target pathologies such as synovium. The general joint condition and patient's expectation are the two key points to surgical indication. (1) A single lateral or medial approch is always sufficient for moderate elbow stiffness. We recommaned the combined medial and lateral approaches rather than posterior approach to treat severe stiff elbows, in which the lateral to reach anterior and medial to reach posterior. (2) General release and clearance should cover the hypertrophic capsule, humeroradial joint, triceps, olecranon fossa, fossa coronoidea, HO. (3) The anterior bundle of the medial collateral ligament (AMCL) and lateral ulnar collateral ligament should be left intact to prevent instability while we further release the ligament contracture. Intraoperative examination is necessory to detect the stability of the elbow, the ligament repair is very important for a functional joint. (4) We recommand ulnar nerve anterior transposition preventively. (5) We believe it reasonable and helpful to adopt a hinged external fixator in severe cases, it provides extra-stability and security for repaired ligaments, facilitate rehabilitation, and a less painful situation leads to more effective outcoming. Aiming to handle the target pathologies blocking mobility as well as the sufficient structures maintaining stability. (1) Preoperative education is very important, it is the doctor's responsibility to notify the importance of rehabilition. (2) We encourage early-stage exercises after surgery, starting from the first postoperative day, which follow a logical sequence of progression with some flexibility in application. The exercises consist of active, assisted, and passive elbow flexion and extension movements. The progressive exercise program is continued for as long as three months after the surgery. (3) During the interval of each exercise session, a compressive cryotherapy device is encouraged to be applied to relieve pain. We have performed a prospective, single-blinded, randomized controlled study to investigate the effect of cryotherapy after elbow arthrolysis. VAS scores were significantly lower in the cryotherapy group during the first 7 postoperative days, both at rest and in motion. (4) The applying of drains and indomethacin aims to reduce the pain as well as the incidence of edema and hetertopic ossification. The patient education and rehabilitation should be throughout the treatment, it will decide the final outcome.

Evaluation of elbow flexion following free muscle transfer from the medial gastrocnemius or transfer from the latissimus dorsi, in cases of traumatic injury of the brachial plexus

ObjectiveTo compare the gain in elbow flexion in patients with traumatic injury of the brachial plexus following muscle transfer from latissimus dorsi with the gain following free muscle transfer from the medial belly of the gastrocnemius. MethodsThis was a retrospective study in which the medical files of a convenience sample of 13 patients operated between 2000 and 2010 were reviewed. Group 1 comprised seven patients who underwent transfers from the gastrocnemius and group 2 (controls) comprised six patients who underwent transfers from the latissimus dorsi. The following functions were evaluated: (1) range of motion (ROM) of elbow flexion, in degrees, using manual goniometry and (2) grade of elbow flexion strength, using a muscle strength scale. Satisfactory results were defined as: (1) elbow flexion ROM≥80° and (2) elbow flexion strength≥M3. The Fisher exact and Kruskal–Wallis tests were used (p<0.05). ResultsThe patients’ mean age was 32 years (range: 17–56) and 72% had been involved in motorcycle accidents. Elbow flexion strength≥M3 was observed in seven patients (100%) in group 1 and in five patients (83.3%) in group 2 (p=0.462). None of the patients presented M5, and one patient (16.7%) in group 2 had a poor result (M2). Elbow flexion ROM with a gain≥80° (daily functions) was found in six patients (86%) in group 1 and in three patients (50%) in group 2 (p=0.1). ConclusionThe patients in group 1 had greater gains in strength and ROM than did those in group 2, but without statistical significance. Thus, transfers from the gastrocnemius become a new surgical option, if other techniques cannot be used.

Muscular coordination of biceps brachii and brachioradialis in elbow flexion with respect to hand position.

Contribution of synergistic muscles toward specific movements over multi joint systems may change with varying position of distal or proximal joints. Purpose of this study is to reveal the relationship of muscular coordination of brachioradialis and biceps brachii during elbow flexion with respect to hand position and biomechanical advantages and disadvantages of biceps brachii. A group of 16 healthy subjects has been advised to perform 20 repetitions of single elbow flexion movements in different hand positions (pronated, neutral, and supinated). With a speed of 20°/s, simultaneously sEMG of biceps brachii and brachioradialis and kinematics of the movement were recorded in a motion analysis laboratory. Normalized to MVC the sEMG amplitudes of both muscles contributing to elbow flexion movements were compared in pronated, supinated, and neutral hand position over elbow joint angle. Significant differences in the contribution of brachioradialis were found in pronated hand position compared to supinated and neutral hand position while the muscular activity of biceps brachii shows no significant changes in any hand position. In conclusion, a statistical significant dependency of the inter-muscular coordination between biceps brachii and brachioradialis during elbow flexion with respect to hand position has been observed depending on a biomechanical disadvantage of biceps brachii.

Ulnar Rotation Osteotomy for Congenital Radial Head Dislocation

To evaluate an ulnar rotation osteotomy for congenital anterior dislocation of the radial head. Nine patients (5 boys and 4 girls aged 6 to 13 years) with congenital anterior dislocation of the radial head were treated with ulnar rotation osteotomy. Magnetic resonance imaging of the elbow showed the proximal radioulnar joint on the anterior-lateral side of the ulna rather than on the lateral side in patients with congenital anterior dislocation of the radial head. On the basis of this finding, we performed an osteotomy on the ulna and laterally rotated the proximal radioulnar joint achieving radial head reduction and restoring the anatomical relationship between the radial head and the capitellum. Clinical and radiographical evaluation of the elbow was performed before surgery and at postoperative follow-up. All patients were followed for 13 to 45 months after surgery. Elbow radiography showed that the radiocapitellar joint was reduced in all patients at the last follow-up visit and that the carrying angle was decreased relative to that in the preoperative condition. Elbow stability and the range of elbow flexion motion were improved at the last follow-up. We did not observe ulnar osteotomy site nonunion or elbow osteoarthritis in these patients. Furthermore, radial head dislocation did not recur. At early follow-up, ulnar rotation osteotomy was a safe and effective method for the treatment of congenital anterior dislocation of the radial head. Therapeutic IV.

Avaliação da flexão do cotovelo após transferência muscular livre do gastrocnêmio medial ou transferência do latíssimo do dorso na lesão traumática do plexo braquial

ObjectiveTo compare the gain in elbow flexion in patients with traumatic injury of the brachial plexus following muscle transfer from latissimus dorsi with the gain following free muscle transfer from the medial belly of the gastrocnemius. MethodsThis was a retrospective study in which the medical files of a convenience sample of 13 patients operated between 2000 and 2010 were reviewed. Group 1 comprised seven patients who underwent transfers from the gastrocnemius and group 2 (controls) comprised six patients who underwent transfers from the latissimus dorsi. The following functions were evaluated: 1) range of motion (ROM) of elbow flexion, in degrees, using manual goniometry; and 2) grade of elbow flexion strength, using a muscle strength scale. Satisfactory results were defined as: 1) elbow flexion ROM ≥ 80°; and 2) elbow flexion strength ≥ M3. The Fisher exact and Kruskal‐Wallis tests were used (P<0.05). ResultsThe patients’ mean age was 32 years (range: 17 to 56) and 72% had been involved in motorcycle accidents. Elbow flexion strength ≥ M3 was observed in seven patients (100%) in group 1 and in five patients (83.3%) in group 2 (p=0.462). None of the patients presented M5, and one patient (16.7%) in group 2 had a poor result (M2). Elbow flexion ROM with a gain ≥ 80° (daily functions) was found in six patients (86%) in group 1 and in three patients (50%) in group 2 (p=0.1). ConclusionThe patients in group 1 had greater gains in strength and ROM than did those in group 2, but without statistical significance. Thus, transfers from the gastrocnemius become a new surgical option, if other techniques cannot be used

The Dermal Suction Increases Range Of Motion Of Voluntary Movements

BACKGROUND: For years, techniques such as massaging and application of external pressure were used for the purpose of myofascial releasing. These techniques focus on the application of pressure to the skin, yet the possibility of using suction as an alternative technique has not been investigated so much. PURPOSE: The investigation was conducted to determine the effectiveness of increasing range of motion of voluntary movements by applying the dermal suction. METHODS: Changes in range of motion of shoulders, elbow and neck regions of 10 healthy adult males were investigated. 30 kilopascal of the dermal suction was applied by using a round suction probe with 1 cm diameter. The probe was glided across the targeted muscles five times within five seconds. For each subject, the range of motions before and after the dermal suction, were measured using an analogue goniometer. RESULT: By applying the dermal suction onto infraspinatus and teres minor, the range of motion for external rotation at the glenohumeral joint significantly increased from 60±14.6 degrees to 68±13.5 degrees (P < .05). The application to the medial side of the elbow joint significantly increased the range of motion of elbow flexion from 144.3±3.6 degrees to 149.1±4.6 degrees (P < .05). The suction was also applied to the left supraclavicular triangle, and found that the range of left rotation at the cervical vertebrae significantly increased from49.3±3.3 degrees to 59.6±6.2 degrees (P < .05). A paired t-test was used for statistical analysis. Discussion:It is evident that the dermal suction applied at the same side of the joint which was moving foward would increase the mobility of skin and subcutaneous tissue, and allow those tissues to glide smoothly by reducing resistance within. For these reasons, it is inferred that the dermal suction increases the range of motion. CONCLUSION: The dermal suction increases range of motion of voluntary movement and induces the smoothness of movement. The method of using suction to increase joint mobility is a unique approach, and further refinement of this approach is hoped for.

Decomposition Method Considering Changes of SMUAP Waveform during Elbow Flexion Movement

Decomposition Method Considering Changes of SMUAP Waveform during Elbow Flexion Movement

Upper limb kinematics after cervical spinal cord injury: a review.

Although a number of upper limb kinematic studies have been conducted, no review actually addresses the key-features of open-chain upper limb movements after cervical spinal cord injury (SCI). The aim of this literature review is to provide a clear understanding of motor control and kinematic changes during open-chain upper limb reaching, reach-to-grasp, overhead movements, and fast elbow flexion movements after tetraplegia. Using data from MEDLINE between 1966 and December 2014, we examined temporal and spatial kinematic measures and when available electromyographic recordings. We included fifteen control case and three series case studies with a total of 164 SCI participants and 131 healthy control participants. SCI participants efficiently performed a broad range of tasks with their upper limb and movements were planned and executed with strong kinematic invariants like movement endpoint accuracy and minimal cost. Our review revealed that elbow extension without triceps brachii relies on increased scapulothoracic and glenohumeral movements providing a dynamic coupling between shoulder and elbow. Furthermore, contrary to normal grasping patterns where grasping is prepared during the transport phase, reaching and grasping are performed successively after SCI. The prolonged transport phase ensures correct hand placement while the grasping relies on wrist extension eliciting either whole hand or lateral grip. One of the main kinematic characteristics observed after tetraplegia is motor slowing attested by increased movement time. This could be caused by (i) decreased strength, (ii) triceps brachii paralysis which disrupts normal agonist–antagonist co-contractions, (iii) accuracy preservation at movement endpoint, and/or (iv) grasping relying on tenodesis. Another feature is a reduction of maximal superior reaching during overhead movements which could be caused by i) strength deficit in agonist muscles like pectoralis major, ii) strength deficit in proximal synergic muscles responsible for scapulothoracic and glenohumeral joint stability, iii) strength deficit in distal synergic muscles preventing the maintenance of elbow extension by shoulder elbow dynamic coupling, iv) shoulder joint ankyloses, and/or v) shoulder pain. Further studies on open chain movements are needed to identify the contribution of each of these factors in order to tailor upper limb rehabilitation programs for SCI individuals.

Aging and limb alter the neuromuscular control of goal-directed movements

The purpose of this study was to determine whether the neuromuscular control of goal-directed movements is different for young and older adults with the upper and lower limbs. Twenty young (25.1 ± 3.9 years) and twenty older adults (71.5 ± 4.8 years) attempted to accurately match the displacement of their limb to a spatiotemporal target during ankle dorsiflexion or elbow flexion movements. We quantified neuromuscular control by examining the movement endpoint accuracy and variability, and the antagonistic muscle activity using surface electromyography (EMG). Our results indicate that older adults exhibit impaired endpoint accuracy with both limbs due to greater time variability. In addition, older adults exhibit greater EMG burst and lower EMG burst variability as well as lower coactivation of the antagonistic muscles. The impaired accuracy of older adults during upper limb movements was related to lower coactivation of the antagonistic muscles, whereas their impaired accuracy during lower limb movements was related to the amplified EMG bursts. The upper limb exhibited greater movement control than the lower limb, and different neuromuscular parameters were related to the accuracy and consistency for each limb. Greater endpoint error during upper limb movements was related to lower coactivation of the antagonistic muscles, whereas greater endpoint error during lower limb movements was related to the amplified EMG bursts. These findings indicate that the age-associated impairments in movement control are associated with altered activation of the involved antagonistic muscles. In addition, independent of age, the neuromuscular control of goal-directed movements is different for the upper and lower limbs.

Validity and reliability of the Kinect within functional assessment activities: Comparison with standard stereophotogrammetry

The recent availability of the Kinect™ sensor, a cost-effective markerless motion capture system (MLS), offers interesting possibilities in clinical functional analysis and rehabilitation. However, neither validity nor reproducibility of this device is known yet. These two parameters were evaluated in this study. Forty-eight volunteers performed shoulder abduction, elbow flexion, hip abduction and knee flexion motions; the same protocol was repeated one week later to evaluate reproducibility. Movements were simultaneously recorded by the Kinect (with Microsoft Kinect SDK v.1.5) MLS and a traditional marker-based stereophotogrammetry system (MBS). Considering the MBS as reference, discrepancies between MLS and MBS were evaluated by comparing the range of motion (ROM) between both systems. MLS reproducibility was found to be statistically similar to MBS results for the four exercises. Measured ROMs however were found different between the systems.

Reacting while moving: influence of right limb movement on left limb reaction

An experiment was designed to determine whether the activation of a muscle group (flexors or extensors) used to produce an ongoing movement of one limb influenced the reaction time and associated initiation of elbow flexion or extension movements of the contralateral limb. Right-handed participants in the bimanual groups were asked to produce a pattern of flexion/extension movements defined by a sine wave (period = 2 s, amplitude = 16°) with the right limb. While performing the right limb movement, participants were instructed that they were to react as quickly as possible by making a flexion or extension movement with their left limb when the cursor they were using to track the sine wave changed color. Participants in the unimanual groups performed the left limb reaction time task but were not asked to make right limb movements. The reaction time stimulus occurred once in each trial and was presented at one of six locations on one of the six cycles comprising the sinusoidal waveform. Participants performed 7 blocks of 6 test trials. Reaction time was calculated as the time interval between the color change of the cursor and the initiation of the response with the left limb. Movement time was calculated as the interval of time between the initiation of the response and the left limb cursor crossing the upper or lower boundary line. Mean reaction of the left limb was significantly influenced by the concurrent type of movement (flexion/extension) of the right limb. Reaction times were shorter on trials in which both limbs were initiating movement with homologous muscles as compared to trials in which the limbs were initiating movement with non-homologous muscles. No differences were detected when the stimuli were presented during the ballistic phase of the right limb movement, and no differences at any position were detected for the unimanual groups. This result is consistent with the notion that neural crosstalk can influence the time required to react to a stimulus but this influence occurs when contralateral muscles are activated.

Estudo Comparativo entre Eletrogoniometria e Fotogrametria Digital

Objective: To evaluate the digital photogrammetry replicability compared to electrogoniometry on the elbow flexion movement. Material and Methods: The sample was composed by 20 healthy and active subjects (8 men and 12 women; 20.1 ± 1.7 years; 60.9 ± 9.3 kg and 169.0 ± 8.8 cm), submitted to electrogoniometry and digital photogrammetry. The subjects were in sitting position with the right arm resting on a table; the shoulder was flexed at 90 degrees with a supinated forearm. The elbow flexion angle was measured with and without fixing the electrogoniometer in three different positions (closed, intermediate, open) randomly, using a manual goniometer (CARCI) adapted with a linear potentiometer and a digital camera (Sony, DSC-S750), and subsequently processed in the Biomed and Fisio Office softwares, respectively. Data were analyzed on the Statistical Package for Social Science (SPSS – 15.0) using the intra-class correlation (ICC) test to evaluate the reproducibility of the electrogoniometry and photogrammetry measures, inter-evaluators and inter-instruments. Results: It was observed a strong reproducibility of the electrogoniometry and photogrammetry for all measures, inter-evaluators (ICC>0.85; P 0.93; P<0.01). Conclusion: The results of this study showed that the digital photogrammetry has high levels of reliability, both inter-evaluators and inter-instruments and thus can be used for physical therapy practice. DESCRIPTORS Goniometry. Photogrammetry. Range of Motion, Articular.

Biomechanical characteristics and speed adaptation during kick double poling on roller skis in elite cross-country skiers

Recent developments in cross-country ski racing should promote the use of kick double poling. This technique, however, has not been the focus in athletes' training and has barely been investigated. The aims of the present study were to develop a function-based phase definition and to analyse speed adaptation mechanisms for kick double poling in elite cross-country skiers. Joint kinematics and pole/plantar forces were recorded in 10 athletes while performing kick double poling at three submaximal roller skiing speeds. A speed increase was associated with increases in cycle length and rate, while absolute poling and leg push-off durations shortened. Despite maintained impulses of force, the peak and average pole/leg forces increased. During double poling and leg push-off, ranges of motion of elbow flexion and extension increased (p < 0.05) and were maintained for hip/knee flexion and extension. Cycle length increase was correlated to increases in average poling force (r = 0.71) and arm swing time (r = 0.88; both p < 0.05). The main speed adaptation was achieved by changes in double poling technique; however, leg push-off showed high variability among elite skiers, thus illustrating important aspects for technique training.

Associated Reactions during a Visual Pursuit Position Tracking Task in Hemiplegic and Quadriplegic Cerebral Palsy

Most previous studies of associated reactions (ARs) in people with cerebral palsy have used observation scales, such as recording the degree of movement through observation. The sensitive quantitative method can detect ARs that are not amply visible. The aim of this study was to provide quantitative measures of ARs during a visual pursuit position tracking task. Twenty-three hemiplegia (H) (mean +/- SD: 21y 8m +/- 11y 10m), twelve quadriplegia (Q) (21y 5m +/- 10y 3m) and twenty-two subjects with normal development (N) (21y 2m +/- 10y 10m) participated in the study. An upper limb visual pursuit tracking task was used to study ARs. The participants were required to follow a moving target with a response cursor via elbow flexion and extension movements. The occurrence of ARs was quantified by the overall coherence between the movements of tracking and non-tracking limbs and the amount of movement due to ARs was quantified by the amplitude of movement the non-tracking limbs. The amplitude of movement of the non-tracking limb indicated that the amount of ARs was larger in the Q group than the H and N groups with no significant differences between the H and N groups. The amplitude of movement of the non-tracking limb was larger during non-dominant than dominant tracking in all three groups. Some movements in the non-tracking limb were correlated with the tracking limb (correlated ARs) and some movements that were not correlated with the tracking limb (uncorrelated ARs). The correlated ARs comprised less than 40% of the total ARs for all three groups. Correlated ARs were negatively associated with clinical evaluations, but not the uncorrelated ARs. The correlated and uncorrelated ARs appear to have different relationships with clinical evaluations, implying the effect of ARs on upper limb activities could be varied.

Planning of Ballistic Movement following Stroke: Insights from the Startle Reflex

Following stroke, reaching movements are slow, segmented, and variable. It is unclear if these deficits result from a poorly constructed movement plan or an inability to voluntarily execute an appropriate plan. The acoustic startle reflex provides a means to initiate a motor plan involuntarily. In the presence of a movement plan, startling acoustic stimulus triggers non-voluntary early execution of planned movement, a phenomenon known as the startReact response. In unimpaired individuals, the startReact response is identical to a voluntarily initiated movement, except that it is elicited 30–40 ms. As the startReact response is thought to be mediated by brainstem pathways, we hypothesized that the startReact response is intact in stroke subjects. If startReact is intact, it may be possible to elicit more task-appropriate patterns of muscle activation than can be elicited voluntarily. We found that startReact responses were intact following stroke. Responses were initiated as rapidly as those in unimpaired subjects, and with muscle coordination patterns resembling those seen during unimpaired volitional movements. Results were striking for elbow flexion movements, which demonstrated no significant differences between the startReact responses elicited in our stroke and unimpaired subject groups. The results during planned extension movements were less straightforward for stroke subjects, since the startReact response exhibited task inappropriate activity in the flexors. This inappropriate activity diminished over time. This adaptation suggests that the inappropriate activity was transient in nature and not related to the underlying movement plan. We hypothesize that the task-inappropriate flexor activity during extension results from an inability to suppress the classic startle reflex, which primarily influences flexor muscles and adapts rapidly with successive stimuli. These results indicate that stroke subjects are capable of planning ballistic elbow movements, and that when these planned movements are involuntarily executed they can be as rapid and appropriate as those in unimpaired individuals.

Changes in kinematic variables at various muscle lengths of human elbow flexors following eccentric exercise

Exercise-induced muscle damage causes a disproportionally larger drop in maximal force when measured at short versus optimal or long muscle lengths, resulting in a shift of the length (angle)-force relationship towards longer lengths. However, little attention has been given to the potential effect of this shift on the rate of force development (RFD) and isotonic function at different muscle lengths. This study examined RFD at various elbow angles and kinematic variables at two different ranges of elbow flexion, so as to include mainly the ascending (S condition) or the descending limb (L condition) of the angle-force curve, following eccentric exercise. Seven male volunteers performed an eccentric exercise protocol with the elbow flexors, which caused significant changes in indicators of muscle damage (P<0.05-0.001). Optimum angle for force generation was significantly shifted towards longer elbow flexors lengths post exercise (P<0.05-0.01). RFD was significantly decreased at all the angles tested but no differences were revealed between angles (P<0.05-0.001). The kinematic variables measured were also significantly impaired following eccentric damage (P<0.05-0.001). Maximal isotonic force showed a greater impairment in the S condition, however no significant differences between the S and L condition were found in maximal angular velocity (MAV) and time, angle and isotonic force needed to achieve MAV. These results suggest that impairment of RFD following muscle damage is not muscle-length dependent and the rightward shift of the angle-force curve is not the determinant of the decline in either RFD or the isotonic performance at the different ranges of the elbow flexion movement.

Mensuração do ângulo articular do cotovelo no teste de tensão neural em indivíduos com hanseníase

A hanseníase é uma patologia crônica e granulomatosa, que atinge a pele e o sistema nervoso periférico pela invasão no sistema imune do Mycobacterium leprae. O objetivo deste estudo foi mensurar o ângulo articular do cotovelo com a aplicação do teste de tensão neural do nervo ulnar em pacientes com hanseníase. Na aplicação do teste de tensão neural, foram utilizadas a goniometria e a fotometria para a mensuração do ângulo articular do cotovelo, sendo que para a realização da fotometria foi utilizada uma câmera Samsung de 12.1 Mega pixels, e os dados foram analisados pelo software Corel Draw X5 (Microsoft®). Foram selecionados 44 indivíduos da Fundação Pró-Hansen, com média de idade de 48,13±12,55 anos, divididos em três grupos: G1, G2 e G3. O G1 compreende voluntários com hanseníase e sensibilidade preservada; o G2, aqueles com hanseníase e com perda de sensibilidade; e o G3, o controle. Na goniometria, foi encontrada diferença significativa (p&lt;0,05) na comparação dos grupos G1 e G2 com o controle tanto do membro direito quanto esquerdo, porém não foi encontrada diferença na comparação entre os dois grupos com hanseníase. Na fotometria, houve diferença entre G2 e o controle bilateralmente e entre o G1 e o controle no lado esquerdo. Comparando-se o lado direito e esquerdo, não foi encontrada diferença em nenhum grupo. Os pacientes com hanseníase apresentaram diminuição da ADM de flexão de cotovelo no teste de tensão neural do ulnar em ambos os lados quando comparados ao grupo controle.