Elbow Extensor Strength Research Articles

The Relationship between Upper Extremity Strength and Instrumental Activities of Daily Living Performance among Elderly Women

The purpose of this study was to assess the relationship between upper extremity strength and the ability to perform instrumental activities of daily living (IADL) independently and to explore how therapists might interpret the results of upper extremity strength evaluations among elderly women. Participants included 29 women (68 to 84 years old) who resided in assisted living facilities. Daily living performance was assessed using five subscales of the Multilevel Assessment Instrument. Grip, lateral pinch, and the strength of selected muscles of the elbow and the shoulder in the dominant upper extremity were tested. Shoulder abductor and external rotator strength were moderately correlated (rs= 0.50 and rs− 0.51, respectively) with IADL function. Shoulder external rotator strength was moderately correlated (rs= 0.55) and elbow extensor strength was fairly correlated (rs= 0.49) with participants' ability to grocery shop. Upper extremity strength measurements within normal limits are not necessarily predictive of IADL independence for elderly women, but measurements below normal limits may indicate IADL limitation. A positive screening result for shoulder weakness or upper extremity strength of more than two standard deviations below norms may warrant in-depth assessment of IADL performance. Alternatively, self-reported limitation in IADL independence may support the need for assessment of upper extremity strength.

Spasticity, Strength, and Gait Changes After Surgery for Cervical Spondylotic Myelopathy

A case report with repeated measures is presented. To describe an objective method for evaluating changes in upper- and lower-extremity spasticity and strength, as well as temporal and kinematic gait variables, after surgical intervention for cervical spondylotic myelopathy. Degenerative cervical spinal disease is a common disorder, with some form of spondylosis demonstrated radiographically in more than 80% of those older than 55 years. Normative pre- and postoperative objective data quantifying spasticity, strength, and gait do not exist. A 65-year-old woman underwent C2-C3 anterior cervical discectomy and fusion for progressive myelopathy secondary to a spondylosis and disc herniation. The measure for spasticity and strength at the ankles and elbows and a gait analysis were collected before surgery and at 11 days, 3 and 6 months after surgery. Spasticity and strength were assessed using a dynamometer, and a six-camera video system was used to record the gait. Preoperative left elbow flexor spasticity was more than 10 times greater than the values for the able bodies. It was reduced to normal levels after surgery. Substantial presurgery weakness was present in the elbow flexors and extensors bilaterally. Elbow extensor strength was at able-body levels after surgery. Gait speed was 57% of the able-body level before surgery and 78% of the able-body level 6 months after surgery. This case study demonstrated the role of biomechanics in characterizing impairments associated with cervical spondylosis and its surgical intervention. Measures for spasticity, strength, and gait taken before and after surgery indicated a favorable outcome. This report provides a foundation for the continued use of biomechanical methods to measure changes in function and impairments associated with surgical intervention of cervical spine disorders.

Correlation between muscle strength and throwing speed in adolescent baseball players

One of the aims of baseball training is to increase the throwing speed of players. It has been assumed previously that increasing muscle strength will increase throwing speed. Studies involving adult baseball players have demonstrated that the strength of shoulder adductors, wrist extensors and elbow extensors have predicted throwing speed.Objective: The aim of this study was to determine if upper limb muscle strength correlates with throwing speed in adolescent baseball players.Setting: This study was carried out in the Faculty of Health Sciences, University of Sydney—laboratory and field-testing.Participants: Eighteen elite adolescent baseball players (aged 13–16 years).Outcome measures: Participants underwent throwing speed tests and shoulder and elbow isometric, concentric and eccentric strength tests on an isokinetic dynamometer.Results: Stepwise regression analysis indicated that 71% of the variation in throwing speed in these adolescent baseball players was explained by isometric internal rotation and concentric elbow extension torque-to-body weight in approximately equal proportions.Conclusions: These results demonstrate that both elbow extensor and shoulder internal rotation strength has a large influence on throwing speed. Therefore, preferential strength training for elbow extension and shoulder internal rotation muscle groups in adolescents, without neglecting the antagonistic muscle groups, is recommended. Physiotherapists involved with adolescent baseball athletes need to be aware of the potential effect that strength increases and muscle imbalances in these muscle groups may have in maturing the musculoskeletal system.

Changes in Movement Symmetry Associated With Strengthening and Fatigue of Agonist and Antagonist Muscles

The hypothesis that strengthening or fatiguing procedures applied on active muscles can affect the symmetry of rapid, discrete movements was tested. Subjects (N = 12) performed rapid, consecutive elbow flexions and extensions between 2 targets before and after (a) applying a strength training program, (b) fatiguing elbow flexors, and (c) fatiguing elbow extensors. The results demonstrated that an increase in strength of elbow extensors caused by applied strength training is associated with an increase in the symmetry ratio (i.e., acceleration time divided by deceleration time) of elbow flexion movements. The symmetry ratio also increased and decreased in movements when agonists and antagonists were fatigued, respectively. Because the strength training and fatiguing procedures are both known to affect muscle force, the data are interpreted as changes in muscles' ability to exert the force while acting as agonists or antagonists. Namely, muscles need equal impulses of force (torque multiplied by time) to accelerate and, thereafter, to decelerate the limb while performing a rapid, discrete movement. The symmetry ratio may therefore be changed so that more time will be provided for muscles that become relatively weaker (compared with their antagonists) because a strengthening or fatiguing procedure has been applied, whereas a shorter time period should be sufficient for action of their stronger antagonists. Although, in the literature, the studied phenomenon has been discussed as a predominantly motor control phenomenon, the present data suggest that the movement symmetry could also be related to agonists' and antagonists' ability to exert force, particularly while performing rapid, discrete movements.

Effect of muscle length on strength and dexterity after stroke.

The effect of muscle length on strength and dexterity after stroke was investigated. The aim was to determine if poor function at a particular muscle length could be attributed solely to differential weakness at this joint angle or whether an additional problem of differential dexterity exists. This descriptive research study measured elbow flexor and extensor strength as well as dexterity at three elbow joint angles: 30 degrees , 60 degrees and 90 degrees flexion. Dexterity was measured independently of strength. Fifteen (seven female, eight male) chronic stroke patients (mean age 67 years) who could actively flex and extend their affected elbow participated. Ten neurologically normal control subjects (mean age 67 years) acted as controls. Strength was measured as peak elbow flexor and extensor torque at three angles; and dexterity was measured as coherence for slow and fast tracking also at three angles. Dexterity was not affected by muscle length but strength was and this finding was the same for both stroke and controls. While the magnitude of the torque-angle curves was not significantly different between stroke and controls, the shape of torque-angle curves was altered after stroke so that both the elbow flexors (p < 0.05) and extensors (p < 0.05) tested weaker in the testing position where they were shortest. Since there was no differential loss of dexterity, it appears that differential loss of strength, especially in the shortened range, may explain the clinical observation of poorer function at one muscle length than another after stroke. Specific training to strengthen the muscles in these ranges is therefore of clinical importance for rehabilitation.

Isokinetic strength of elbow extensor muscles correlates with race time in wheelchair half marathon racers.

It has been reported that grasping power and isometric muscle strength of elbow extensors in fine wheelchair racers were greater than the poor racers in the wheelchair full marathon. The purpose of the present study was to investigate the relationship between muscle strength of elbow extensors and flexors and the race time in wheelchair half marathon race. Four wheelchair half marathon racers who completed the half marathon division of the 16th Oita International Wheelchair Marathon (OIWM) in 1996 participated in the present study. The day before the race, all subjects reported to the training room and the isokinetic muscle strength of elbow extensor and flexor muscle groups was measured at angular speeds of 60 degrees, 120 degrees and 240 degrees/sec using the isokinetic dynamometer. There was a significant correlation between race time and isokinetic muscle strength of the elbow extensors at 60 degrees, 120 degrees and 240 degrees/sec, but not flexor muscles. Our findings suggest that increased muscle strength of elbow extensors may improve the race time in wheelchair half marathon race.

Torque, total work, power, torque acceleration energy and acceleration time assessed on a dynamometer: reliability of knee and elbow extensor and flexor strength measurements.

Isometric torque and isokinetic peak torque, total work, power, torque acceleration energy and acceleration time at 30, 120 and 240 degrees.s-1 of the knee and elbow extensors and flexors were measured using an isokinetic dynamometer in 24 healthy women. Intrasession variation of the measurements was evaluated and the short-term and long-term reliability was assessed by repeating all procedures after averages of 2 and 30 days, respectively. The effect of learning on peak torque during a session was also evaluated. Moreover, the effect of general warming-up on knee extensor and flexor strength was examined on a separate day. Using correlations, numerous studies have indicated that muscle strength measurements are reliable. Correlations, however, are inappropriate and misleading in studies on reliability. In the present study reliability of each strength variable was expressed as the coefficient of variation (CV). With the protocol used, neither learning nor warming-up had any significant effect on strength. As expected, intra-session variation tended to be less than short-term and long-term inter-session variation. The CVs for strength variables measured 30 days apart exceeded 5% for all variables and rose to 107% for acceleration time. Substantial between-subject variation of individual CVs were found. The study demonstrated that muscle strength measurements may be highly unreliable in the individual subject.

Muscle strength and body composition: associations with bone density in older subjects

This study investigated the relationship between isokinetic muscle strength and bone density (SPA and DPA) in men and women aged 45-77 yr. Regression models were adjusted for age, weight, smoking status, and calcium supplementation. Elbow extensors (but not flexors) peak torque was correlated with radial density in men (partial r = 0.26, P < 0.05) and women (partial r = 0.24, P < 0.05). Knee flexor (but not extensor) peak torque in women was significantly correlated with spine density (partial r = 0.28, P < 0.05), and muscle mass was significantly correlated with Ward's triangle density (partial r = 0.35, P < 0.05). No associations between knee flexor or extensor muscle strength and spine or femur bone density were observed in men. Fat-free mass (FFM, hydrodensitometry) was associated with all bone density sites in males and females (partial r = 0.30-0.55; P < 0.05). These results demonstrate that 1) significant associations observed between elbow extensor strength and radial bone density in men and women may reflect loading along the longitudinal axis of the radius associated with elbow extensor activity; and 2) significant associations exist between knee flexor muscle strength and lumbar density in women only. Additionally, the associations between FFM and bone density do not necessarily reflect associations between isokinetic muscle strength and bone density.

Reliability of the Nicholas Manual Muscle Tester on Upper Body Strength in Children Ages 8-10

Hand-held dynamometry has proven reliable in assessing adult strength. The primary purpose of this study was to determine its reliability in children. Secondary purposes included investigating strength differences between males and females and between dominant (D) and nondominant (ND) sides. Subjects were 8-, 9-, and 10-year-old boys (n=63) and girls (n=54). The Nicholas Manual Muscle Tester (NMMT) was used to measure maximum isometric force of D and ND elbow flexors, elbow extensors, and shoulder abductors. Retest measurements were taken 4 to 7 days later. Results indicated that (a) correlation coefficients ranging from .72 to .90 were statistically significant; (b) except for males’ ND elbow extensor strength, a series of paired t tests revealed no significant differences between test and retest strength values; (c) a series of paired t tests revealed no significant strength differences between D and ND sides other than for males’ elbow extensor strength for the test phase; and (d) a series of unpaired t tests revealed statistically significant differences between males and females on a majority of the muscle groups. The NMMT appears to be a quick and reliable testing instrument for determining maximal isometric force in children.

Physiological Characteristics of Elite Judo Athletes

In order to provide some understanding of the physiological capacities underlying successful judo performance, representative values for a variety of physiological variables were determined in nationally ranked male (n = 18) and female (n = 9) judo athletes. Body composition, aerobic capacity, isokinetic elbow and knee flexor and extensor strength, and muscle fiber size and composition of the vastus lateralis were examined. Comparisons across weight divisions indicate that the values of many characteristics varied as a function of size. As weight division increased, relative VO2 decreased (r = -0.53 and -0.63 for males and females, respectively), % body fat increased (r = 0.64, 0.72), and the cross sectional areas of Type I (r = 0.55, 0.77) and Type IIA (r = 0.47, = 0.76) muscle fibers increased. Among females in particular, athletes in the higher weight divisions were stronger relative to LBM than those in the lower division. These results indicate that the physiological profiles of lower and upper weight division elite judo players differ markedly. It is suggested that the factors responsible for success may be specific to each weight division and may represent a compromise between making weight and maximizing physiological capacities and performance.

Physiological and performance responses to overtraining in elite judo athletes

To determine the effect of large and sudden increases in training volume on performance characteristics and the feasibility of using overtraining syndrome symptoms to monitor performance changes, 15 elite judo athletes were examined through 10 wk of training. Athletes performed their regular regimens of resistance (3 d.wk-1), interval (2 d.wk-1), and judo (5 d.wk-1) training in weeks 1-4. Interval and resistance training volumes increased by 50% in weeks 4-8 and returned to baseline in weeks 9-10. Judo training volume was unchanged in weeks 1-8 but increased by 100% in weeks 9-10. Assessments were made in weeks 2, 4, 8, and 10. Isokinetic strength of elbow and knee extensors and flexors increased significantly from weeks 2 to 4 (3-13%), was unchanged from weeks 4 to 8, and decreased significantly (6-12%) from weeks 4 to 10. Total time for 3 x 300 m intervals increased (P less than 0.05) between weeks 2 and 4 and between weeks 4 and 8, while total time for 5 x 50 m sprints decreased (P less than 0.05) from weeks 8 to 10 (less than 2%). Body fat percentage decreased (P less than 0.05) from weeks 2 to 10. Body weight, submaximal and maximal aerobic power, resting (sleeping) systolic and diastolic pressures, resting (sleeping) submaximal and maximal heart rates, exercising blood lactate levels, and vertical jump performance did not change significantly with increases in training volume. These results suggest that 6 wk of overtraining may affect some but not all aspects of performance and that performance may be affected before symptoms of the overtraining syndrome appear.

Relative Strength of Seven Upper Extremity Muscle Groups in Hemiparetic Stroke Patients

This study was undertaken to determine whether or not some upper extremity muscle groups are affected more than others after a stroke, and subsequently to identify which muscle group was impaired the most in each of three pairs of opposing muscle groups. The static force production (strength) of seven upper extremity muscle groups was assessed bilaterally in 69 patients, all of whom had suffered an initial stroke. When compared with the values obtained in the nonparetic extremity, the relative strength was not consistent across the seven paretic upper extremity muscle groups. Paretic elbow extensor strength was preserved more than elbow flexor strength. In the paretic shoulder, internal rotator and extensor strengths were preserved more than external rotator and abductor strengths. The muscle strength imbalance, which tends to exist between the paretic shoulder depressors and elevators, and its possible influence on other problems that can occur in the hemiparetic shoulder are discussed.

Proprioceptive Neuromuscular Facilitation Versus Weight Training for Enhancement of Muscular Strength and Athletic Performance

This study was designed to examine the effects of proprioceptive neuromuscular facilitation (PNF) and weight training (WT) on muscular strength and athletic performance. Thirty college women were randomly assigned to one of three groups: WT, PNF, and control. WT and PNF subjects trained 3 days a week for 8 weeks. All subjects were tested for changes in knee and elbow extensor strength, throwing distance, and vertical jump. The WT group increased strength by 19.3% for knee extension and 20.4% for elbow extension while the PNF group increaseil22.1 and 29.1 %, respectively. PNF also increased throwing distance by 25% and vertical jump by 16% while WT had increases of 12.8 and 9.9% respectively. These findings indicate PNF might be superior to WT in athletic performance enhancement and, therefore, the better modality for athletic conditioning and injury rehabilitation. J Orthop Sports Phys Ther 1986;7(5):250-253.

Window accidents.

<h3>Objective</h3> To evaluate whether deficits of elbow flexor and extensor muscle strength exist in lateral epicondylalgia (LE) in comparison with a healthy control population. <h3>Design</h3> Cross-sectional study. <h3>Participants</h3> 150 participants with unilateral LE were compared with 54 healthy control participants. <h3>Main outcome measures</h3> Maximal isometric elbow flexion and extension strength were measured bilaterally using a purpose-built standing frame such that gripping was avoided. <h3>Results</h3> The authors found significant side differences in elbow extensor (−6.54 N, 95% CI −11.43 to −1.65, p=0.008, standardised mean difference (SMD) −0.45) and flexor muscle strength (−11.26 N, 95% CI −19.59 to −2.94, p=0.009, SMD −0.46) between LE and control groups. Within the LE group, only elbow extensor muscle strength deficits between sides was significant (affected–unaffected: −2.94 N, 95% CI −5.44 to −0.44). <h3>Conclusion</h3> Small significant deficits of elbow extensor and flexor muscle strength exist in the affected arm of unilateral LE in comparison with healthy controls. Notably, comparing elbow strength between the affected and unaffected sides in unilateral epicondylalgia is likely to underestimate these deficits. <h3>Trial Registration</h3> Australian New Zealand Clinical Trials Register ACTRN12609000051246.

Isometric and Eccentric Strength of Elbow Flexors and Extensors

Isometric and eccentric maximum strength of elbow flexors and extensors were measured with a special tension-meter at five steps of elbow joint angulation (45°, 60°, 90°, 130°, 160°). Thirty-one female students served as subjects.The results are summarized as follows:1) Independently of the elbow flexors or extensors and the isometric contraction or eccentric contraction, the muscular strength is maximum at 90° among all the angulations tested.2) Irrsepectively of whether voluntary contractions are performed isometrically or eccentrically, the elbow flexors can exert greater strength than the elbow extensors except when the elbow joint is bent too extremely.3) It is a common tendency between the elbow flexors and extensors that the maximum strength of eccentric contractions is greater than that of isometric contractions.These results were discussed in comparison with previous works in this field.