Arm Research Papers - Academia.edu (original) (raw)

Aim. The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. Methods. Thirty-one... more

Aim. The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. Methods. Thirty-one healthy adolescent girls, of which 11 age-matched control subjects [C], 10 basketballers (BP) and 10 volleyballers (VP) participated to the study. The throwing performance was assessed by seated backward overhead ball throw (SBOMBT) and seated chest pass throw (SCPT) using a 3-kg rubber medicine ball. Instead, the vertical jumping performance was evaluated by squat jump (SJ) and countermovement jump with (CMJ-AS) and without arm swing (CMJ) using Optojump system (Microgate srl, Italy). Results. During SJ and CMJ with and without arm swing VP group showed a higher vertical jump performance than BP and C ones. In particular we showed that VP exhibited a higher flight time and jump height than C (P<0.05) in SJ, CMJ and CMJ-AS tests. Players showed higher...

Creatine supplementation in humans has been reported to enhance power and strength both in normal subjects and in patients with various neuromuscular diseases. The purpose of this study was to examine the effects of supplementation on... more

Creatine supplementation in humans has been reported to enhance power and strength both in normal subjects and in patients with various neuromuscular diseases. The purpose of this study was to examine the effects of supplementation on exercise performance and maximal voluntary isometric muscular contraction (MVIC) in Amyotrophic Lateral Sclerosis (ALS) patients.We report the results obtained in 28 patients with probable/definite

Document the biomechanics of the pitching motion to help provide insight about the etiology of common injuries seen in adolescent baseball pitchers. Kinematic and kinetic data for the upper and lower extremities, thorax, and pelvis were... more

Document the biomechanics of the pitching motion to help provide insight about the etiology of common injuries seen in adolescent baseball pitchers. Kinematic and kinetic data for the upper and lower extremities, thorax, and pelvis were collected from 24 adolescent pitchers, using modern three-dimensional computerized motion-analysis techniques. Original information regarding forearm and wrist motion was reported in this study and were consistent with expected motions for the fastball pitch. Average excursion of motion was: pronation/supination 63 +/- 15 degrees, wrist flexion/extension 44 +/- 14 degrees, and ulnar/radial deviation 12 +/- 4 degrees. Explosive forearm motion occurred between ball release (BR) and maximal glenohumeral internal rotation (GH-MIR) with a peak pronation velocity of 2051 +/- 646 degrees.s(-1). The majority of internal/external and abduction/adduction shoulder motion was attributed to the glenohumeral motion. Internal glenohumeral rotation range of motion w...

Humans walk bipedally, and thus, it is unclear why they swing their arms. In this paper, we will review the mechanisms and functions of arm swinging in human gait. First, we discuss the potential advantages of having swinging arms.... more

Humans walk bipedally, and thus, it is unclear why they swing their arms. In this paper, we will review the mechanisms and functions of arm swinging in human gait. First, we discuss the potential advantages of having swinging arms. Second, we go into the detail on the debate whether arm swing is arising actively or passively, where we will conclude that while a large part of arm swinging is mechanically passive, there is an active contribution of muscles (i.e. an activity that is not merely caused by stretch reflexes). Third, we describe the possible function of the active muscular contribution to arm swinging in normal gait, and discuss the possibility that a Central Pattern Generator (CPG) generates this activity. Fourth, we discuss examples from pathological cases, in which arm swinging is affected. Moreover, using the ideas presented, we suggest ways in which arm swing may be used as a therapeutic aid. We conclude that (1) arm swing should be seen as an integral part of human bi...

Debate exists concerning the effect of contraction velocity on muscle damage, and few human studies have yet to address this issue. This study examined whether the velocity of eccentric exercise affected the magnitude of muscle damage.... more

Debate exists concerning the effect of contraction velocity on muscle damage, and few human studies have yet to address this issue. This study examined whether the velocity of eccentric exercise affected the magnitude of muscle damage. Twelve untrained subjects performed a series of slow velocity isokinetic eccentric elbow flexions (SV: 30 degrees . s (-1)) of one arm and a fast velocity exercise (FV: 210 degrees . s (-1)) of the other arm, separated by 14 days. In order to standardise the time under tension (120 s) for the two conditions, the number of muscle actions for SV was 30 and 210 for FV. Criterion measures consisted of maximal voluntary torque for isometric, concentric (4 velocities) and eccentric contractions (2 velocities), range of motion (ROM) and relaxed elbow joint angle (RANG), upper arm circumference, muscle soreness and plasma creatine kinase (CK) activity. Measures were taken before, immediately after, 0.5 hour and 24 - 168 hours (240 hours for CK) after each ecc...

The incidence of lymphoedema was studied in 200 patients following a variety of treatments for operable breast cancer. Lymphoedema was assessed in two ways: subjective (patient plus observer impression) and objective (physical... more

The incidence of lymphoedema was studied in 200 patients following a variety of treatments for operable breast cancer. Lymphoedema was assessed in two ways: subjective (patient plus observer impression) and objective (physical measurement). Arm volume measurement 15 cm above the lateral epicondyle was the most accurate method of assessing differences in size of the operated and normal arm. Arm circumference measurements were inaccurate. Subjective lymphoedema was present in 14 per cent whereas objective lymphoedema (a difference in limb volume > 200 ml) was present in 25.5 per cent. Independent risk factors contributing towards the development of subjective late lymphoedema were the extent of axillary surgery (P < 0.05), axillary radiotherapy (P < 0.001) and pathological nodal status (P < 0.10). The risk of developing late lymphoedema was unrelated to age, menopausal status, handedness, early lymphoedema, surgical and radiotherapeutic complications, total dose of radiation, time interval since presentation, drug therapy, surgery to the breast, radiotherapy to the breast and tumour T stage. The incidence of subjective late lymphoedema was similar after axillary radiotherapy alone (8.3 per cent), axillary sampling plus radiotherapy (9.1 percent) and axillary clearance alone (7.4 per cent). The incidence after axillary clearance plus radiotherapy was significantly greater (38.3 per cent, P < 0.001). Axillary radiotherapy should be avoided in patients who have had a total axillary clearance.

This chapter is a brief account of fundamentals of the equilibrium-point hypothesis or more adequately called the threshold control theory (TCT). It also compares the TCT with other approaches to motor control. The basic notions of the... more

This chapter is a brief account of fundamentals of the equilibrium-point hypothesis or more adequately called the threshold control theory (TCT). It also compares the TCT with other approaches to motor control. The basic notions of the TCT are reviewed with a major focus on solutions to the problems of multi-muscle and multi-degrees of freedom redundancy. The TCT incorporates cognitive aspects by explaining how neurons recognize that internal (neural) and external (environmental) events match each other. These aspects as well as how motor learning occurs are subjects of further development of the TCT hypothesis.

Human gait is an important indicator of health, with applications ranging from diagnosis, monitoring, and rehabilitation. In practice, the use of gait analysis has been limited. Existing gait analysis systems are either expensive,... more

Human gait is an important indicator of health, with applications ranging from diagnosis, monitoring, and rehabilitation. In practice, the use of gait analysis has been limited. Existing gait analysis systems are either expensive, intrusive, or require well-controlled environments such as a clinic or a laboratory. We present an accurate gait analysis system that is economical and non-intrusive. Our system is based on the Kinect sensor and thus can extract comprehensive gait information from all parts of the body. Beyond standard stride information, we also measure arm kinematics, demonstrating the wide range of parameters that can be extracted. We further improve over existing work by using information from the entire body to more accurately measure stride intervals. Our system requires no markers or battery-powered sensors, and instead relies on a single, inexpensive commodity 3D sensor with a large preexisting install base. We suggest that the proposed technique can be used for co...

The article discusses the biomechanical processes that occur during an overhead throw. This activity is highly specialized and requires full and proper function from the shoulder joint. It consists of active and passive stabilization and... more

The article discusses the biomechanical processes that occur during an overhead throw. This activity is highly specialized and requires full and proper function from the shoulder joint. It consists of active and passive stabilization and synchronous work of the accelerating and decelerating muscles. The process of the overhead throw can be divided into several phases that differ from each other in biomechanical parameters and involvement of specific muscles.

BackgroundDespite widespread recommendations regarding posture during computer use, associations between specific postures and musculoskeletal health are not well characterized.Despite widespread recommendations regarding posture during... more

BackgroundDespite widespread recommendations regarding posture during computer use, associations between specific postures and musculoskeletal health are not well characterized.Despite widespread recommendations regarding posture during computer use, associations between specific postures and musculoskeletal health are not well characterized.MethodsSix hundred and thirty-two newly hired computer users were followed prospectively to evaluate associations between posture and neck or shoulder (N/S) and hand or arm (H/A) musculoskeletal symptoms and musculoskeletal disorders. Participants' postures were measured at entry and they reported symptoms on weekly diaries. Participants reporting symptoms were examined for specific disorders. Multivariate Cox regression models were used to estimate associations between postural variables and risk of symptoms and disorders, controlling for confounding variables.Six hundred and thirty-two newly hired computer users were followed prospectively to evaluate associations between posture and neck or shoulder (N/S) and hand or arm (H/A) musculoskeletal symptoms and musculoskeletal disorders. Participants' postures were measured at entry and they reported symptoms on weekly diaries. Participants reporting symptoms were examined for specific disorders. Multivariate Cox regression models were used to estimate associations between postural variables and risk of symptoms and disorders, controlling for confounding variables.ResultsKeying with an inner elbow angle > 121°, greater downward head tilt, and presence of armrests on the participants chair were associated with lower risk of N/S symptoms or N/S disorders. Keying with elbow height below the height of the “J” key and the presence of a telephone shoulder rest were associated with a greater risk of N/S symptoms or N/S disorders. Horizontal location of the “J” key > 12 cm from the edge of the desk was associated with a lower risk of H/A symptoms and H/A disorders. Use of a keyboard with the “J” key > 3.5 cm above the table surface, key activation force > 48 g, and radial wrist deviation of > 5° while using a mouse was associated with a greater risk of H/A symptoms or H/A disorders. The number of hours keying/week was associated with H/A symptoms and disorders.Keying with an inner elbow angle > 121°, greater downward head tilt, and presence of armrests on the participants chair were associated with lower risk of N/S symptoms or N/S disorders. Keying with elbow height below the height of the “J” key and the presence of a telephone shoulder rest were associated with a greater risk of N/S symptoms or N/S disorders. Horizontal location of the “J” key > 12 cm from the edge of the desk was associated with a lower risk of H/A symptoms and H/A disorders. Use of a keyboard with the “J” key > 3.5 cm above the table surface, key activation force > 48 g, and radial wrist deviation of > 5° while using a mouse was associated with a greater risk of H/A symptoms or H/A disorders. The number of hours keying/week was associated with H/A symptoms and disorders.ConclusionsThe results suggest that the risk of musculoskeletal symptoms and musculoskeletal disorders may be reduced by encouraging specific seated postures. Am. J. Ind. Med. 41:236–249, 2002. © 2002 Wiley-Liss, Inc.The results suggest that the risk of musculoskeletal symptoms and musculoskeletal disorders may be reduced by encouraging specific seated postures. Am. J. Ind. Med. 41:236–249, 2002. © 2002 Wiley-Liss, Inc.

The hip intracyclic velocity variability and the index of coordination in front crawl swimming were examined in relation to performance level. 22 swimmers were assigned to either an elite or a recreational swimming group and performed 4... more

The hip intracyclic velocity variability and the index of coordination in front crawl swimming were examined in relation to performance level. 22 swimmers were assigned to either an elite or a recreational swimming group and performed 4 swim trials at different paces relative to their individual maximum velocity. A velocity meter system was set to determine intracyclic velocity variability and video analysis allowed the determination of the index of coordination. Mean intracyclic velocity variability was lower in the elite swimmers than the recreational swimmers (14.39 ± 1.97 vs. 17.80 ± 4.23%, p<0.05), and remained stable with swim pace (i. e., the relative velocity) for the elite group, whereas it increased for the recreational group (p<0.05). The elite swimmers were characterized by a lower mean index of coordination than the recreational swimmers (-9.6 ± 7.1 vs. -6.9 ± 5.0%, p<0.05), but it increased with swim velocity in the elite group and showed only a tendency in th...

The phases of the football throw need definition so that muscle activation patterns during the overhead football throw can be fully described. Electromyographic analysis of shoulder musculature can better define muscle activation patterns... more

The phases of the football throw need definition so that muscle activation patterns during the overhead football throw can be fully described. Electromyographic analysis of shoulder musculature can better define muscle activation patterns during the football throw. Descriptive anatomic study. Videos of 20 elite-level quarterbacks were reviewed to define phases of the overhead football throw; 14 recreational male athletes underwent electromyography and motion analysis testing. Four sequential phases of the football throw were consistently observed. Early cocking (49% +/- 11% of throw) was initiated at rear foot plant and continued to maximal shoulder abduction and internal rotation. Late cocking (20% +/- 6%) started at maximal shoulder abduction and internal rotation and ended with maximal shoulder external rotation. The acceleration phase (15% +/- 4%) began with maximal shoulder external rotation and ended with ball release. Follow-through (16% +/- 5%) was defined as the phase from ...