Arm Flexion Research Articles

Caffeine Supplementation Had No Effect on Endurance Capacity in Elderly Subjects Who Had Abstained from Caffeine-Containing Nutrition for 8 Hours

Background: In this study, we investigated the effect of acute caffeine ingestion on physical performance after only 8 hours of caffeine abstinence. Methods: The study was a randomized, double-blind, cross-over study and included 30 healthy subject aged ≥70 years who had been recruited by their general practitioner. The participants abstained from caffeine for 8 hours (overnight) and the next morning they received placebo and then caffeine (6 mg/kg), or caffeine and then placebo at an interval of 1 week. One hour after the intervention we measured cycling endurance (ergometer), perceived effort during cycling (Borg scale), postural stability (force platform), and maximal isometric arm flexion strength and endurance (dynamometer chair). Blood samples were taken before the intervention, before cycling, after 5 minutes of cycling, and at exhaustion. Results: The participants had a usual coffee intake of six cups/day and after 8 hours of caffeine abstinence the plasma concentration of caffeine was 4.1 μM. Caf...

Activation timing of postural muscles during bilateral arm flexion in self-timing, oddball and simple-reaction tasks

Background We investigated the effect of time constraint on activation timing of postural muscles during bilateral arm flexion in self-timing, oddball and simple-reaction tasks. Methods Thirteen healthy adults flexed their arms from a suspended position with maximum speed and stopped at the shoulder level. For erector spinae-longissimus (ES), biceps femoris (BF), and gastrocnemius (GcM), onset timing of burst activation with respect to the anterior deltoid (AD), and the displacement of the center of pressure in the anteroposterior direction (CoPy) were analyzed. Results AD reaction time was significantly shorter in the simple-reaction task than oddball task, suggesting that time constraint would be lower in the task order noted above and affected the state of postural preparation. The following properties were found in the onset timing of postural muscle: (1) the onset timing of BF and GcM were earlier in the task order noted above, and (2) the earliest activated distal muscle in the self-timing task was activated later in the simple-reaction task. CoPy displacement was smaller in the same task order as the onset timing. Conclusions It appears that with sufficient postural preparation, the focus of postural control is on the reduction of postural disturbance and earlier lower leg muscle activation.

Pelvic Induced Trunk Posture Limits Shoulder ROM and Trunk Rotation

Exaggerated kyphosis and protracted shoulder postures increase scapular anterior tilt, abduction and lateral rotation compromising shoulder function. Excessive posterior tilt increases spinal flexion and shoulder protraction altering the arthrokinematics of the intervertebral joints. Shoulder motion combined with trunk rotation is thus likely affected by spinal posture which has implications for sport performance, injury and shoulder dysfunction. PURPOSE: To determine the effect of trunk posture on arm flexion, abduction, and trunk rotation ranges of motion (ROM). Method: Twenty-two healthy college students free of recent shoulder or spinal injury gave written informed consent. An 8 segment model of the upper body: head, spine, pelvis and both scapulae, clavicles, and humeri, was created. Three movement tasks (arm abduction, flexion, and trunk rotation) in 3 sitting trunk postures (neutral (N), full posterior tilt (P), and full anterior tilt (A)) were recorded using Vicon Nexus and analyzed in Visual3D. Movements were repeated right and left. Differences in arm abduction, flexion, and trunk rotation ROM were assessed across postures with one-way repeated measures ANOVAs. RESULTS: Average pelvic tilt and trunk flexion, respectively, were -1 ± 7° and 4 ± 7° for A, -10 ± 7° and 4 ± 8° for N, and -21 ± 7°and 21 ± 15° for P; positive values are anterior tilt/flexion. Arm abduction, flexion, and right trunk rotation ROM were all reduced in P as compared to N and A with arm abduction decreasing the most (Table). CONCLUSIONS: Sitting trunk posture does effect active arm ROM and trunk rotation in healthy subjects. Future research should examine the effect of trunk postures on similar movements performed during sports such as a golf drive.Table: Arm and Trunk ROM.

Postural recovery following voluntary arm movement is impaired in people with chronic low back pain

Study designRecovery of postural equilibrium following bilateral voluntary arm movement was evaluated using a case-control study, with 13 subjects with chronic LBP and 13 age- and gendermatched control subjects. ObjectivesTo evaluate control of the centre-of-pressure (COP), as a marker of the quality of control of postural equilibrium associated with voluntary arm movements, in people with and without LBP. Summary of background data. When healthy individuals perform rapid voluntary arm movements, small spinal movements (preparatory movement) opposite to the direction of the reactive moments precede voluntary arm movements. Evaluation of trunk movement in people with LBP suggests that this strategy is used infrequently in this population and is associated with an increased spinal displacement following arm flexion. As the preparatory spinal movement was also thought to be an anticipatory mechanism limiting postural perturbation caused by arm movements, we hypothesized that LBP subjects would have compromised control of postural equilibrium following arm flexion. MethodsSubjects performed bilateral voluntary rapid arm flexion while standing on support surface of different dimensions with eyes opened or closed. ResultsResults indicated that people with LBP consistently took longer to recover postural equilibrium and made more postural adjustments in different stance conditions. However, there was no increase in the excursion of the COP during the recovery period in the LBP group. ConclusionThese data suggest that while COP is tightly controlled during postural recovery, the finetuning of the control of postural equilibrium is compromised in people with LBP. Postural control dysfunctions should be considered in the management of chronic low back pain.

In vivo gleno-humeral joint loads during forward flexion and abduction

To improve design and preclinical test scenarios of shoulder joint implants as well as computer-based musculoskeletal models, a precise knowledge of realistic loads acting in vivo is necessary. Such data are also helpful to optimize physiotherapy after joint replacement and fractures. This is the first study that presents forces and moments measured in vivo in the gleno-humeral joint of 6 patients during forward flexion and abduction of the straight arm. The peak forces and, even more, the maximum moments varied inter-individually to a considerable extent. Forces of up to 238%BW (percent of body weight) and moments up to 1.74%BWm were determined. For elevation angles of less than 90° the forces agreed with many previous model-based calculations. At higher elevation angles, however, the measured loads still rose in contrast to the analytical results. When the exercises were performed at a higher speed, the peak forces decreased. The force directions relative to the humerus remained quite constant throughout the whole motion. Large moments in the joint indicate that friction in shoulder implants is high if the glenoid is not replaced. A friction coefficient of 0.1–0.2 seems to be realistic in these cases.

Computer-assisted analysis of human upper arm flexion by 4D-visualization based on MRI

4D-visualization of the human upper arm based on sequential or dynamic MRI may be useful in functional orthopedic disorders and surgical planning. A cascade of 4D-visualization approaches have been applied including deformation of the soft tissue surfaces and muscular contraction. Skeletal structures and the epifascial tissue comprising vascular structures are included in the 4D-visualization. Sequential MRI (T2-weighted spin echo sequences) scans of a healthy volunteer's upper extremity were obtained. The skeletal, muscular, and epifascial tissues were segmented. For 4D-rendering of the elbow joint, surface models of the humerus, the ulna, and the radius, were displaced with respect to the movement. For 4D-visualization of the soft tissue, the processed MRI data were subjected to highly transparent direct volume rendering with special two-tone transfer functions designed with regard to the application, e.g., muscular inner structure or fasciae. For rendering of time dependent behavior, the visualization was continuously updated. Continuous deformation of muscular inner structure and fasciae, and dynamics of muscle fibers could be differentiated in 4D-visualizations of the upper extremity. Using sequential MRI scans, this work was constrained by the high sagittal slice thickness and separation. 4D-visualization of the upper extremity based on sequential MRI is feasible and provides a realistic appearance in comparison with anatomical drawings and preparations. The 4D-visualization method may be useful for detecting and monitoring muscular pathologies and lesions.

Fatal ischemic stroke in a patient receiving lenalidomide for multiple myeloma

Lenalidomide is a novel treatment that significantly increases urvival time in patients with relapsed or refractory multiple yeloma [1]. Known side effects include neutropenia, thromboytopenia and venous thromboembolism [1]. Recently, a 54-year-old female was admitted to our hospital ith a previous history of multiple myeloma. She was treated with enalidomide (25mg PO) in combination with the usual regimen f dexamethasone 40mg PO once a week. Other actual medication ncluded paracetamol, pregabaline and fentanyl patches for neuopathic pain. One week later, she was found on the floor by her on in an unconscious state. It could be reconstructed that she had een unconscious for approximately one day when she was found. ater, her brother reported that twodaysprior to admission shehad xperienced a sudden weakness on the right side of the body, for hich she had not soughtmedical attention. Besides suffering from ultiplemyeloma, hermedical historywas unremarkable. She had o previous history of smoking, vascular disease, diabetes, or any ther known risk factors for stroke. Six months previously, under uspicion of cardiac amyloidosis, she had undergone an extensive nalysis by a cardiologist which had revealed no abnormalities. Upon admission to the hospital, she was comatose (E1M4V1), ith a pathological extension of the right arm and flexion of the eft arm on a painful stimulus. Hyperreflexia and a Babinski’s sign n the right side were present. A cerebral CT-scan revealed large ypodense areas in the vascular territories of both middle cereral arteries (Fig. 1). Apart from an elevated serum creatine kinase 1499 IU/l), presumably from prolonged immobilization on the oor, laboratory investigations revealed no abnormalities. The limted options for treatmentwere discussedwith the patient’s family, ho agreed to wait and see. The patient was admitted to the eurology ward where she died the following day. No additional

Evaluation of a Novel Basic Life Support Method in Simulated Microgravity

If a cardiac arrest occurs in microgravity, current emergency protocols aim to treat patients via a medical restraint system within 2-4 min. It is vital that crewmembers have the ability to perform single-person cardiopulmonary resuscitation (CPR) during this period, allowing time for advanced life support to be deployed. The efficacy of the Evetts-Russomano (ER) method has been tested in 22 s of microgravity in a parabolic flight and has shown that external chest compressions (ECC) and mouth-to-mouth ventilation are possible. There were 21 male subjects who performed both the ER method in simulated microgravity via full body suspension and at +1 Gz. The CPR mannequin was modified to provide accurate readings for ECC depth and a metronome to set the rate at 100 bpm. Heart rate, rate of perceived exertion, and angle of arm flexion were measured with an ECG, elbow electrogoniometers, and Borg scale, respectively. The mean (+/- SD) depth of ECC in simulated microgravity was lower in each of the 3 min compared to +1 G2. The ECC depth (45.7 +/- 2.7 mm, 42.3 +/- 5.5 mm, and 41.4 +/- 5.9 mm) and rate (104.5 +/- 5.2, 105.2 +/- 4.5, and 102.4 +/- 6.6 compressions/min), however, remained within CPR guidelines during simulated microgravity over the 3-min period. Heart rate, perceived exertion, and elbow flexion of both arms increased using the ER method. The ER method can provide adequate depth and rate of ECC in simulated microgravity for 3 min to allow time to deploy a medical restraint system. There is, however, a physiological cost associated with it and a need to use the flexion of the arms to compensate for the lack of weight.

Music is in the Muscle: How Embodied Cognition May Influence Music Preferences

Music is Intimately Connected with Body movements. Until recently, research has almost exclusively examined the impact of music on body movements. Yet findings on embodied cognition in other domains suggest that the influence might also work in the opposite direction: Real or imagined body movements during music listening may codetermine music preferences. We had participants listen to music and concurrently activate muscles whose innervation has been shown to be associated with "positive" and "negative" affect (activation vs. inhibition of smiling muscles, vertical vs. horizontal head movements, and arm flexion vs. arm extension). Activation of the positively associated muscle groups led to higher preference ratings for the music pieces than activation of the negatively associated ones. A first exploration of candidate explanations for the effect suggests that it is most likely due to conditioning processes. It is concluded that body movements, both real and imagined, may play an important role in the development of music preferences.

Influence of Bilateral Motor Behaviors on Flexible Functioning: An Embodied Perspective

To examine the influence of bilateral motor behaviors on flexibility performance, two studies were conducted. Previous research has shown that when performing unilateral motor behavior that activates the affective and motivational systems of approach versus avoidance (arm flexion vs. extension), it is the congruence between laterality and motor activation that determines flexibility-rigidity functioning (Cretenet & Dru, 2009). When bilateral motor behaviors were performed, a mechanism of embodiment was revealed. It showed that the flexibility scores were determined by the match between the respective qualities of congruence of each of the unilateral motor behaviors performed. These results bring to light an overall embodied mechanism associated with the compatibility of the cognitive impact(s) of each motor behavior performed.

Approach and withdrawal actions modulate the startle reflex independent of affective valence and muscular effort

The startle reflex is modulated during processing of pleasant and unpleasant affective cues. One explanation of this finding contends that approach and withdrawal motivational processes are key to explaining the effect. Undergraduates performed arm flexion and arm extension actions shown elsewhere to reliably elicit approach and withdrawal motives, respectively. Results showed that arm extension (a withdrawal action) was associated with the largest startles, followed by a neutral control action and arm flexion (an approach action). This pattern was not attributable to the subjective pleasantness or muscular effort associated with the actions. Results support motivational priming accounts of startle reflex modulation.

Changes in kinematics and trunk electromyography during a 2000 m race simulation in elite female rowers

Achieving excellence in rowing requires optimization of technique to maximize efficiency and force production. Investigation of the kinematics of the trunk, upper and lower extremity, together with muscle activity of the trunk, provides an insight into the motor control strategies utilized over a typical race. Nine elite female rowers performed a 2000 m race simulation. Kinematic data of the trunk and extremities, together with electromyography (EMG) activity of spinal and pelvic extensor and flexor muscles, were compared at 250 and 1500 m. At 1500 m, there was greater dissociation in the timing of leg extension and arm flexion and delayed trunk extension. Also at 1500 m, the spine demonstrated a delayed peak extension angular velocity of the T4-T7 and L3-S1 spinal segments in the early drive along with delayed and increased peak extension angular velocity of T10-L1 and L1-L3 spinal segments during the late drive. Trunk muscle fatigue was not evident; however, the abdominals demonstrated larger EMG burst areas at 1500 m. Alterations in trunk kinematics suggest that the trunk acts as a less stiff lever on which to transfer the forces of the legs to the arms and handle. Increased abdominal activity may reflect increased demand to control the trunk, given the altered coordination between the legs, trunk and arms.

Electromechanical Delay in Ballistic Movement of Superior Limb: Comparison between Karate Athletes and Nonathletes

The aim of the study was to analyze electromechanical delay in a ballistic movement of the superior limb. 10 male karate athletes and 9 nonathletes (without karate experience) performed a motor skill as fast and powerfully as possible, with impact on a makiwara (karate training instrument). For each participant, 10 choku-zuki performances were analyzed. Kinematics and surface electromyographic (EMG) activity of the anterior and posterior portions of deltoid, pectoralis major, latissimus dorsi, triceps brachii, and biceps brachii were recorded. Athletes had significantly shorter delay in arm flexion agonist muscles and significantly higher delay in arm flexion antagonist muscles and in forearm extension agonists. Results suggest that enhanced performance in athletes was mainly due to motor learning.

Double calibration: An accurate, reliable and easy-to-use method for 3D scapular motion analysis

The most recent non-invasive methods for the recording of scapular motion are based on an acromion marker (AM) set and a single calibration (SC) of the scapula in a resting position. However, this method fails to accurately measure scapular kinematics above 90° of arm elevation, due to soft tissue artifacts of the skin and muscles covering the acromion. The aim of this study was to evaluate the accuracy, and inter-trial and inter-session repeatability of a double calibration method (DC) in comparison with SC. The SC and DC data were measured with an optoelectronic system during arm flexion and abduction at different angles of elevation (0–180°). They were compared with palpation of the scapula using a scapula locator. DC data was not significantly different from palpation for 5/6 axes of rotation tested (Y, X, and Z in abduction and flexion), where as SC showed significant differences for 5/6 axes. The root mean square errors ranged from 2.96° to 4.48° for DC and from 6° to 9.19° for SC. The inter-trial repeatability was good to excellent for SC and DC. The inter-session repeatability was moderate to excellent for SC and moderate to good for DC. Coupling AM and DC is an easy-to-use method, which yields accurate and reliable measurements of scapular kinematics for the complete range of arm motion. It can be applied to the measurement of shoulder motion in many fields (sports, orthopaedics, and rehabilitation), especially when large ranges of arm motion are required.

Does a Positive Neer Impingement Sign Reflect Rotator Cuff Contact with the Acromion?

One possible cause of shoulder pain is rotator cuff contact with the superior glenoid (cuff-glenoid contact) with the arm in flexion, as occurs during a Neer impingement sign. It has been assumed that the pain with a Neer impingement sign on physical examination of the shoulder was secondary to the rotator cuff making contact with the anterior and lateral acromion. We determined if the arm position where pain occurs with a Neer impingement sign would correlate with the position where the rotator cuff made contact with the superior glenoid, as determined by arthroscopic evaluation. We prospectively studied 398 consecutive patients with a positive Neer impingement sign during office examination and used a handheld goniometer to measure (in degrees of flexion) the arm position in which impingement pain occurred. During subsequent arthroscopy, the arm was moved into a similar position, and we measured the arm's position in flexion at the point the rotator cuff made contact with the superior glenoid using a handheld goniometer. We compared the degrees of flexion at which pain occurred preoperatively and at which there was cuff-glenoid contact. Among the 398 patients, 302 (76%) had arthroscopically documented cuff-glenoid contact, whereas 96 did not. For the 302 patients with a positive Neer sign preoperatively and with arthroscopically documented cuff-glenoid contact, the average preoperative impingement pain position was 120.1°±26.7°, similar to that of the average intraoperative cuff-glenoid contact position of 120.6°±14.7°. Our data suggest pain associated with a positive Neer sign more often relates to contact of the rotator cuff with the superior glenoid than to contact between the rotator cuff and acromion. Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Teaching and Learning Guide for: Body in Mind: The Role of Embodied Cognition in Self‐Regulation

Teaching and Learning Guide for: Body in Mind: The Role of Embodied Cognition in Self‐Regulation

Anticipatory postural muscle activity associated with bilateral arm flexion while standing in individuals with spastic diplegic cerebral palsy: A pilot study

Compared to automatic postural responses to external perturbation, little is known about anticipatory postural adjustments in individuals with spastic diplegic cerebral palsy. In this study, we examined whether anticipatory activation of postural muscles would be observed before voluntary arm movement while standing in individuals with spastic diplegia. Seven individuals with spastic diplegia (SDCP group, 12–22 years) and 7 age- and gender-matched individuals without disability (Control group) participated in this study. Participants performed bilateral arm flexion at maximum speed at their own timing while standing, during which electromyographic (EMG) activities of focal and postural muscles were recorded. In both groups, the erector spinae (ES) and medial hamstring (MH) muscles were activated in advance of the anterior deltoid muscle (AD), which is a focal muscle of arm flexion. Although start times of ES and MH with respect to AD were similar in the 2 groups, increases in EMG amplitudes of ES and MH in the anticipatory range from −150 ms to +50 ms, with respect to burst onset of AD, were significantly smaller in the SDCP group than in the Control group. These findings suggest that individuals with spastic diplegia have the ability to anticipate the effects of disturbance of posture and equilibrium caused by arm movement and to activate postural muscles in advance of focal muscles. However, it is likely that the anticipatory increase in postural muscle activity is insufficient in individuals with spastic diplegia.

Location and sequence of muscle onset in deep abdominal muscles measured by different modes of ultrasound imaging

Various modes of ultrasound (US) imaging have been introduced as an alternative to electromyography for determining muscle onset. The purpose of this study was to compare the agreement between US motion-mode (US m-mode) and US strain rate (US SR) derived from tissue velocity imaging in determining latency time, location and sequence of muscle onset in abdominal muscles using the same data set (contractions). Twenty-four subjects performed four rapid arm flexions in response to a light signal while US recordings were made from the abdominal muscles on the contralateral side. The examined muscles were transversus abdominis (TrA), superficial and deep obliquus internus abdominis (OI deep and OI sup), and obliquus externus abdominis (OE). The results showed that the two methods detected the first muscle onset on average within 0.1 ms (95% CI; ±1.4 ms) of each other. US SR detected the second muscle onset on average 27 ms after US m-mode. While US SR and US m-mode can be used interchangeably to detect the first muscle onset, the location of both first onset and subsequent muscle onsets can be reliably detected by US SR only. Furthermore, this study indicates that OI may be functionally subdivided into a superficial and deep region, with onset in OI deep occurring on average 53 ms before OI sup. First onset was detected more frequently in OI than in TrA (65% versus 25% of detected onsets, 10% were equal).

Traction lesion of the brachial plexus during bodyflying

Bodyflying is a flying sport similar to skydiving. The experience of bodyflying is close to that of skydiving, however, bodyflying does not require a jump out of a plane or a parachute, the flight is enabled by a vertical air stream column with a speed of up to 180 km/h in a vertical wind tunnel. Bodyflying has been considered to be a sports activity in a completely safe environment with no serious complications. We report two cases of traction lesions of the brachial plexus during first-time bodyflying with predominant affection of the root C6. To the best of our knowledge, this pattern of traction injury of the brachial plexus has not yet been reported. Immediately following a bodyflying teaching session, a 35-year-old male noticed a marked weakness in arm and finger flexion and to a lesser degree in arm extension of the left upper limb. Furthermore, he observed numbness of the radial side of the left forearm. Contrast-enhanced magnetic resonance imaging of the cervical spine was unremarkable. On examination of the left upper limb, there was weakness in biceps flexion [grade 4-/5 according to the British Medical Research Council grading system (BMRC)], triceps extension (grade 4?/5), and wrist/finger flexors (grade 4?/5). Examination of sensation was diminished over the radial aspect of the left forearm extending down over the first three digits (C6). The biceps and brachioradialis reflexes were absent on the left side. Electroneurographic examinations of nerve conduction velocities and amplitudes of the left median and ulnar nerve were unremarkable, but F-wave studies of the left median nerve (see Fig. 1) demonstrated an increased latency on the left (C6). Electromyographic needle examination (EMG) revealed no abnormal spontaneous activity, but recruitment was predominantly reduced in the left biceps (see Fig. 2) and slightly reduced in the left deltoid (C5/C6), whereas it was normal in the left triceps (C7). Because of acute weakness of the left arm during a firsttime bodyflying session, a 17-year-old female had to interrupt the session. Immediately following the session, the patient was unable to move her left arm and she noticed a numbness of the radial side of the left forearm. On examination of the left upper limb, strength testing demonstrated flaccid paresis in shoulder abduction and anteversion (grade 4/5), biceps flexion and supination/ pronation of the forearm (grade 2/5), and wrist/finger flexors (grade 4/5) without affection of intrinsic muscles of the hand. Sensation was diminished over the radial aspect of the left forearm extending down over the first two digits. The biceps reflex was absent and the brachioradialis reflex was diminished on the left. Nerve conduction velocity studies of sensory nerves demonstrated a slightly decreased left median nerve response (C6). The EMG revealed abnormal spontaneous activity in the left biceps brachii muscle and recruitment was markedly reduced. There was no abnormal spontaneous activity in the left deltoideus and brachioradialis, but recruitment was reduced, indicative of a lesion of the C5 and C6 segment. Misjudgement of vertical air stream with a speed of up to 180 km/h can result in uncoordinated compensating movements of the arms. In this situation, an inadvertent relaxation of the arm muscles can cause the arm to be overextended or overelevated by the strong vertical air stream and may thereby cause a traction lesion of the brachial plexus. Additionally, the bodyflying instructor’s N. Galldiks (&) K. A. M. Pauls G. R. Fink W. F. Haupt Department of Neurology, University Hospital of Cologne, Kerpener Str. 62, 50924 Cologne, Germany e-mail: norbert.galldiks@uk-koeln.de

AnimatLab: A 3D graphics environment for neuromechanical simulations

The nervous systems of animals evolved to exert dynamic control of behavior in response to the needs of the animal and changing signals from the environment. To understand the mechanisms of dynamic control requires a means of predicting how individual neural and body elements will interact to produce the performance of the entire system. AnimatLab is a software tool that provides an approach to this problem through computer simulation. AnimatLab enables a computational model of an animal's body to be constructed from simple building blocks, situated in a virtual 3D world subject to the laws of physics, and controlled by the activity of a multicellular, multicompartment neural circuit. Sensor receptors on the body surface and inside the body respond to external and internal signals and then excite central neurons, while motor neurons activate Hill muscle models that span the joints and generate movement. AnimatLab provides a common neuromechanical simulation environment in which to construct and test models of any skeletal animal, vertebrate or invertebrate. The use of AnimatLab is demonstrated in a neuromechanical simulation of human arm flexion and the myotactic and contact-withdrawal reflexes.