Biomedical subjects

Z Dvir

Publications and source records attributed to Z Dvir.

At least 19 recordsLinked to original sources

PubMed2006

Quadriceps and hamstring isokinetic strength and electromyographic activity measured at different ranges of motion: a reproducibility study.

Isokinetic strength measurements of the quadriceps and hamstring that are commonly conducted using a 90 degrees range of motion (RoM) may involve some risk to specific knee patient groups. Testing these muscles at a much shorter RoM may reduce the risk but in order to render this method clinically acceptable the reproducibility of the derived test findings has to be established. Therefore the main objective of this study was to assess the reproducibility of isokinetic peak torque and normalized EMG scores of these muscles based on 90 degrees (0-90 degrees flexion, LR) and three successive short RoMs: 0-30 degrees (SR1), 30-60 degrees (SR2) and 60-90 degrees (SR3). Eight healthy subjects were tested three times with a 2 week between-session interval. All tests were performed on the dominant limb and consisted of maximal concentric and eccentric exertions. The velocities applied were 90 degrees /s for LR and 30 degrees /s for each of the SRs. Findings indicated no between-session improvement in strength. Based on the coefficient of variation the measurement error for all isokinetic strength scores remained stable throughout the testing sessions ranging 0.6-13.9% with the absolute majority of instances less than 10%. The reproducibility of the EMG scores was poorer ranging 1.5-25% and 0.5-19% for the quadriceps and hamstring, respectively. It is concluded that testing of knee muscles at short (30 degrees ) RoMs does not compromise the reproducibility of the strength or EMG scores derived from the commonly used RoM of 90 degrees . However, whereas strength was reproducible to within the accepted clinical standards, the corresponding EMG scores were characterized by a wider error band.

Adult↗

PubMed2005

Testing knee extension and flexion strength at different ranges of motion: an isokinetic and electromyographic study.

The main objective of this study was to explore the mechanical and electrical output of thigh muscles derived from a range of motion (RoM) of 90 degrees (0-90 degrees flexion, LR) and the three successive RoMs: 0-30 degrees (SR1), 30-60 degrees (SR2) and 60-90 degrees (SR3). Thirteen men took part in the study. In view of the torque-velocity relationship and in order to render the test conditions as equivalent as possible, LR was tested at 90 degrees /s while the corresponding velocity for all SRs was 30 degrees /s. The findings indicated very good agreement between LR and SR2 in terms of absolute strength (particularly the concentric), within muscle eccentric to concentric strength ratios, between muscles (agonist to antagonist) strength ratios and the normalized IEMG (expressed in muV/Nm). An agreement was also noted between the mean eccentric peak torque of the knee flexors at LR and SR1 and between the mean eccentric peak torque of the knee extensors at LR and SR3. However, in general there was a lesser agreement between LR and SR1 or SR3. It is suggested that testing thigh muscles in the middle sector of knee motion (SR2) yields strength and EMG data that are close and well correlated with those derived from testing the knee along the commonly used (0-90 degrees ) RoM.

Adult↗

PubMed2004

Electro-oculographic measures in patients with chronic whiplash and healthy subjects: a comparative study.

BACKGROUND: Despite their high incidence, costs, and long lasting disability, whiplash associated disorders (WAD) lack an identifiable objective pathology that explains their acute or chronic symptoms. OBJECTIVE: In view of previous suggestions of a possible effect of neck torsion on several electro-oculography (EOG) parameters, the main objective of this study was to examine their applicability in differentiating patients from uninvolved subjects. METHODS: Smooth pursuit and saccadic eye movements were assessed in 26 patients with chronic WAD and 23 healthy subjects. All tests were executed in three neck positions: neutral and rotations to left and right. RESULTS: Neck torsion did not influence eye movement performance of either the WAD or healthy groups. However, compared with the healthy group, patients with WAD had significantly lower smooth pursuit velocity gain (SPVG) (p = 0.01) and prolonged saccadic latency (p = 0.001), irrespective of neck position. CONCLUSIONS: Despite scattered differences that reached significance, the electro-oculographic measures used in this study do not seem to offer a clinically relevant method for differentiating between patients with WAD and normal subjects.

Adult↗

PubMed2001

Maximal versus feigned active cervical motion in healthy patients: the coefficient of variation as an indicator for sincerity of effort.

STUDY DESIGN: Maximal and submaximal (feigned) cervical motions in healthy patients were compared. OBJECTIVE: To test the efficiency of the coefficient of variation in differentiating maximal (sincere) from submaximal (feigned) cervical motion in healthy patients. SUMMARY OF BACKGROUND DATA: Although limitation of cervical motion is a recognized impairment, no well-founded approach for verifying the degree to which a patient is maximizing his or her performance is available currently. METHODS: A new ultrasound-based system for three-dimensional motion analysis of the head was used to test 25 healthy patients (22 women and 3 men) ages 26 to 48 years. During the first test, (Test 1), the patients were asked initially to move the head maximally at a self-determined velocity in all the primary directions: flexion, extension, right and left rotation, and right and left lateral flexion. They then were presented with a short vignette describing a fictitious accident and asked, using the same protocol, to perform the same types of cervical motions as if they had experienced an injury. No further instructions were provided. A retest (Test 2) in reverse order (feigned effort first) took place 1 to 16 weeks (mean, 3.3 weeks) later. RESULTS: The range of motion and average velocity were significantly smaller (P = 0.0001) in the feigned than in the maximal performance in all directions and on both tests. Feigned range of motion and velocity also were significantly reduced in Test 2 (P = 0.006), as compared with those in Test 1 (P = 0.0001). The range of motion coefficient of variation in the feigned performance (CVf) remained stable on the retest, but was significantly larger on both tests (P < 0.001) than the corresponding CV derived from maximal performance (CVm). Furthermore, a case-by-case analysis showed that whereas the American Medical Association guidelines identified only 16% of the feigned cases, the use of CVf and CVm resulted in a corresponding rate of 87%. Tolerance intervals at 95% and 99% indicated total separation between the distributions of CVf and CVm, respectively. The average velocity-based CVf and CVm were not of a comparable differentiating power. CONCLUSIONS: This study indicates that in healthy patients, feigned performance may be differentiated from maximal (sincere) performance effectively and reproducibly using the coefficient of variation.

Adult↗

PubMed2001

Identifying feigned isokinetic trunk extension effort in normal subjects: an efficiency study of the DEC.

STUDY DESIGN: A test-retest comparison of maximal and feigned trunk extension effort in normal subjects was performed. OBJECTIVE: To test the robustness of an index termed DEC for differentiating maximal from feigned effort in normal subjects. SUMMARY OF BACKGROUND DATA: Previous studies have indicated that the DEC, which is the difference between the eccentric to concentric strength ratio at two test velocities, is a powerful identifier of feigned effort. This has been found for various muscle groups including the trunk extensors. However, whether this efficiency is affected by exposure to the protocol, learning, or other factors had not been examined. METHODS: Using a KinCom isokinetic dynamometer, 18 men and 17 women were tested twice within 1 to 2 weeks. Concentric and eccentric efforts of the trunk extensors were exerted using a short range of motion (20 degrees ) and two test velocities (10 degrees and 40 degrees per second). In the first part of each test, participants exerted maximal force against the lever arm, whereas in the second part they were to feign their maximal capability, pretending the presence of injury. RESULTS: In both Tests I and II, the feigned DEC scores (DECf) of all the participants were greater than the maximal DEC (DECm) scores (P = 0.0001). Repeated measurement analysis showed that neither DECm nor DECf varied systematically from Test 1 to Test 2. On the basis of the individual male scores, the DEC cutoff score of 0.41 was 100% efficient in Test 1 at differentiating feigned from maximal effort, with neither false-positive nor false-negative cases. Test 2 had a single false-positive case (efficiency 95%), and the optimal cutoff score was 0.275. In the female group, the corresponding efficiency of the DEC was 82% (optimal cutoff, 0.35) for Test 1 and 70% (optimal cutoff, 0.25-0.35) for Test 2. A statistical model for tolerance intervals at 90%, 95% and 99% indicated higher cutoff values for women than men. CONCLUSION: In healthy subjects, the DEC effectively differentiates feigned from maximal performance.

Adult↗

PubMed2001

Reproducibility and validity of a new test protocol for measuring isokinetic trunk extension strength.

OBJECTIVE: To investigate the reproducibility and validity of isokinetic trunk extension strength scores obtained using a range of motion of 20 degrees and velocities of 10 and 40 degrees /s. BACKGROUND: Common protocols for testing trunk extension strength incorporate a range of motion of 40 degrees or more and test velocities of between 30 and 180 degrees/s. These test parameters may be neither necessary for portraying the strength profile of the muscles involved nor suitable for patients impaired with low back dysfunction. DESIGN: Test-retest of maximal concentric and eccentric isokinetic trunk extension strength in healthy subjects. METHODS: 17 women and 18 men were tested twice within 1-2 weeks. Tests were performed with subjects positioned in sitting. RESULTS: The trunk extension strength scores revealed excellent agreement with the expected physiological moment-velocity curve. On average women's trunk extension strength was 62% that of men (range: 59.3-64.4%). The test-retest correlation coefficients were generally higher in women (0.70-0.87) than in men (0.52-0.78) and significant at P=0.01. The standard error of measurement ranged between 13 and 21 N m for women and between 35 and 50 N m for men, which were equivalent to 9% and 15% of the mean strength in women and men, respectively. CONCLUSION: This study indicates that the present protocol may be validly applied in assessing trunk extension strength in normal women. RELEVANCE: Reproducible and valid trunk extension strength findings are essential if measurable strength deficiency of the extensors is to be formally accepted as an impairment. The present protocol incorporates or meets most of the relevant problems associated with trunk concentric and eccentric strength testing, and hence has the potential of becoming a standard method for clinical applications.

Adult↗

PubMed2001

Cervical circumduction in normal subjects: a study of maximal versus feigned effort.

The feasibility of using the coefficient of variation in conjunction with motion parameters derived from head circumduction to obtain a compact criterion for differentiating maximal from feigned cervical motion was evaluated. Twenty-five healthy subjects were measured twice during a period of 3 weeks using an ultrasonography-based motion analysis system. Subjects were asked to produce maximal motion of the spine as well as to feign limitation. Extracted from the displayed traces of head circumduction, the angular values of the primary motions of flexion, extension, right and left lateral flexion, as well as their additive score (AS) were determined. No test-retest differences were indicated. The average range of motion (ROM) was significantly smaller and the coefficient of variation of the ROM was significantly larger in the feigned compared with the maximal performance in both tests. However, tolerance interval analysis indicated that the coefficient of variation could not effectively separate between the effort levels, being particularly deficient with respect to AS. In addition, a differential sensitivity in identifying false-negative cases as a function of the movement paradigm was revealed. This study indicates that in healthy subjects, the use of a complex cervical movement such as circumduction cannot serve for differentiating between maximal and feigned performance using the coefficient of variation. The results may also point out the existence of a mechanism for adjusting proportional reductions among the primary cervical motions that result in excellent repeatability even in feigned efforts.

Adult↗

PubMed2000

Reproducibility and instrument validity of a new ultrasonography-based system for measuring cervical spine kinematics.

OBJECTIVE: To report instrument validity of CMS 70P, a new ultrasonography-based system for spatial kinematic analysis of the spine and its application in studying the reproducibility of cervical motion findings in healthy subjects. BACKGROUND: Reproducibility of cervical motion has been investigated using various instruments and consisting in most cases of short test-retest time intervals of between minutes to days. METHODS: Performance of the instrument was validated against a digital inclinometer, at ranges of motion compatible with actual cervical motion. To study reproducibility, 25 healthy individuals, 22 women and 3 men aged 26-48 were tested twice within an average time interval of 3.3 weeks. Performed in the seated position and at a self-determined pace, cervical motion was defined in terms of head motion relative to a sternal (reference) system, in all six primary motions: flexion, extension, right rotation, left rotation, right lateral flexion and left lateral flexion. RESULTS: The system exhibited excellent agreement with the digital inclinometer, establishing its instrument validity for testing cervical motion. No significant differences were indicated between the test and retest for both the net maximal displacements and average velocities. The correlation coefficients for the single plane motions (e.g. flexion+extension) were higher than those derived for the primary motions, and ranged between 0.78 (sagittal plane) and 0.88 (frontal plane). The magnitude of the standard error of the measurement reflected the same trend with the lowest value recorded for the frontal plane. The self-selected velocity at which these motions were performed was similar in the frontal and saggital planes but was significantly higher for the transverse plane (rotations). CONCLUSIONS: This study indicates that spanned over time intervals that are measured in weeks, cervical motion findings derived from the CMS 70P are well reproducible. Findings also imply the need for a more stringent control of subject positioning and stabilization. RELEVANCE: Reduction of range of motion and average is typically observed in various pathologies of the cervical spine and is regarded, together with pain, as a major impairment. Therefore, valid assessment of cervical motion which is essential for follow-up and treatment outcome strongly depends on reproducibility of the findings. This study indicates that acceptable reproducibility is maintained over periods of time which are clinically meaningful using the system described herewith.

Adult↗

PubMed2000

EMG and strength correlates of selected shoulder muscles during rotations of the glenohumeral joint.

OBJECTIVE: To identify activation patterns of several muscles acting on the shoulder joint during isokinetic internal and external rotation. DESIGN: Combined EMG and isokinetic strength analysis in healthy subjects. BACKGROUND: EMG studies of the shoulder region revealed intricate muscular activation patterns during elevation of the arm but no parallel studies regarding pure rotations of the joint could be located. METHODS: Fifteen (n=30 shoulders) young, asymptomatic male subjects participated in the study. Strength production during isokinetic concentric and eccentric internal and external rotations at 60 and 180 degrees /s was correlated with the EMG activity of the rotator cuff, biceps, deltoid and pectoralis major. Analysis of the smoothed EMG related to the timing of onset of the signal and to the normalized activity at the angle of the peak moment. Determination of the association between the EMG and the moment was based on strength ratios. RESULTS: Findings indicated that for both types of rotations, the rotator cuff and biceps were active 0.092+/-0.038-0.215+/-0.045 s prior to the initiation of the actual movement and 0.112-0.034 s prior to onset of deltoid and pectoralis major activity. These differences were significant in all of the eight conditions (P<0.05). In terms of the strength ratios, strong association was found between electrical activity and moment production in the subscapularis and infraspinatus (r(2)=0.95 and 0. 72, respectively) at the low and high angular velocities. CONCLUSIONS: Prior to actual rotation of the shoulder joint, normal recruitment of the rotator cuff and biceps is characterized by a non-specific presetting phase which is mainly directed at enhancing the joint 'stiffness' and hence its stability. Once movement is in progress, the EMG patterns of these muscles become movement specific and are correlated with the resultant moment. RELEVANCE: Muscular dysfunction relating to delayed onset activity or altered activation patterns, due to pain, perturbed mechanics or disturbed neural activation have been implicated as concomitant factors in other joint associated pathologies. Through highlighting the role of the rotator cuff in shoulder joint rotations, this study lends further support to the argument that a parallel situation may prevail with respect to shoulder joint dysfunction. This could lead to the development of rehabilitation protocols aimed specifically at redressing such dysfunction.

Adolescent↗

PubMed1999

Identification of feigned grip effort using isokinetic dynamometry.

OBJECTIVE: To investigate the feasibility of applying isokinetic dynamometry for identifying submaximal grip strength. DESIGN: Measurement of maximal and feigned concentric and eccentric strength at high and low contraction velocities. BACKGROUND: Identification of feigned grip strength is a highly problematic issue which has been challenged using various techniques, invariably related to isometric efforts. This study is based on recent research which has indicated that isokinetic dynamometry was highly efficient in identifying feigned efforts in other major muscle groups. METHODS: Seventeen healthy women aged 20-25 took part in the study. Prior to executing the feigned effort, subjects were told to exert lower than the maximal grip strength in an attempt to obtain financial compensation for a simulated injury to hand musculature which in fact did not result in weakness of grip. RESULTS: Findings indicated that based on a parameter termed DEC which was defined as the difference between the ratios of the eccentric to concentric strength at the high and low velocities, feigned efforts could very effectively be identified (P<0.0001). Furthermore, a multivariate model enabled this identification to be described in terms of the level of confidence by which a claim concerning weakness of grip may be proclaimed as genuine or insincere. CONCLUSIONS: Though the neuromotor mechanisms responsible for grip strength may differ from those acting with respect to other muscle groups, the inability to adjust the eccentric and concentric force components during submaximal efforts is probably a general feature. RELEVANCE: Isokinetic dynamometry is a powerful method for quantifying various aspects of muscle performance. However, its application in the medicolegal area of muscle weakness has only recently been explored. Combined with previous research, this study strongly indicates that if certain trauma or pathology-related weakness does not result in variations in the force-velocity characteristics of the affected muscles, than this technique has the potential to validly differentiate between patients who have a genuine reason for compensation and those ('symptom magnifiers') who do not.

Adult↗

PubMed1999

Reproducibility of performance and certainty of judgment in maximal vs feigned muscular effort.

Detection of feigned muscular effort is a highly challenging topic in the medicolegal arena. Modern dynamometric methods have enabled a much higher accuracy in deciding whether the effort in question is indeed genuine or submaximal. Since in feigning the target, however, performance may fluctuate even within a single testing session, reproducibility cannot be assured. In actual claims, the statistical nature of certainty in proclaiming a feigned effort must be well understood by those involved in deciding the fate of a claim.

Deception↗

PubMed1997

Differentiation of submaximal from maximal trunk extension effort: an isokinetic study using a new testing protocol.

STUDY DESIGN: An evaluation of the relations between concentric and eccentric contractions of the trunk extensors and extension effort performed at maximal and submaximal levels. OBJECTIVE: To define quantitative parameter(s) derivable from isokinetic dynamometry that may differentiate submaximal from maximal trunk extension moment. SUMMARY OF BACKGROUND DATA: Using various consistency-related parameters, researchers in previous studies have not been able confirm the potential of isokinetic dynamometry for identifying submaximal effort during trunk extension. METHODS: Twenty healthy subjects, 8 women and 12 men without low back pain history, aged 21 to 30 years, took part in this study. Testing consisted of three experimental conditions using four intermittent concentric and eccentric contractions at 20 degrees and 60 degrees/second. The first condition, in which subjects were asked to exert maximal concentric and eccentric effort, served as the baseline. In the second condition, subjects were asked to exert 50% of the force measured in the first condition. In the third condition, subjects repeated the second condition but were asked to exert the best reproducible level of force. RESULTS: The highest differentiating power among the experimental conditions was attributed to the intervelocity difference between the concentric and eccentric contractions (P < 0.0001). CONCLUSIONS: This protocol effectively differentiates submaximal from maximal trunk extension effort in normal subjects.

Adult↗

PubMed1997

Grade 4 in manual muscle testing: the problem with submaximal strength assessment.

OBJECTIVE: To compare the static moment of force required for a muscle group to support a limb segment against gravity with the maximal dynamic moment it can generate. DESIGN: Based on anthropometric measures of both sexes and theoretical calculations, the estimated anti-gravity static muscular moments (MGM) at the shoulder, elbow, hip and knee joints were compared with published data relating to the isokinetic strength (MIM) of the same muscle groups. RESULTS: The ratio of static to dynamic moment, MGM/MIM, was drastically higher in muscles operating on the proximal compared with the more distal joints. In women, the values of this ratio in the shoulder, hip, elbow and knee muscles were 7-27%, 5-65%, 7% and 5-10% respectively. The corresponding figures in men were 7-21%, 4-44%, 8-10% and 5-8%. The ratios relating to the abductors, flexors and extensors of the hip joint were substantially higher in women than in men. CONCLUSIONS: Since MGM and MIM correspond to grades 3 and 5 in manual muscle testing, the findings of this theoretical analysis indicate that elbow and knee muscles assessed as having grade 4 may generate as low as 10% of their maximal strength. With regard to shoulder and hip muscles the corresponding values are typically around 20% and 30-40% Coupled with the very limited human precision in sensing of force, these findings indicate that where quantitative targets in muscle strength conditioning are set or when an accurate measure of impairment is being sought, grade 4 cannot and should not serve as a valid criterion.

Disability Evaluation↗

PubMed1997

An isokinetic study of submaximal effort in elbow flexion.

The purpose of this study was to examine the efficiency of a protocol, used in previous studies in an extended form, for differentiation of submaximal from maximal effort in elbow flexion. 15 healthy men aged 21 to 55 years took part in two experimental conditions. In the maximal effort condition subjects were instructed to exert maximal concentric and eccentric efforts and in the best reproducible effort condition subjects were asked to exert similar but submaximal concentric and eccentric efforts which they could best reproduce. The amount of effort, represented by the average moment, was measured relative to two ranges of motion, 30 degrees and 60 degrees, at two angular speeds, 20 degrees/sec. and 60 degrees/sec., using 4 intermittent concentric-eccentric contractions. Both the eccentric/concentric strength ratios as well as the difference between these ratios at the high and the low speeds were highly effective in distinguishing maximal from submaximal efforts. Moreover, since the protocol was equally effective irrespective of the range of motion, it may be used to differentiate submaximal from maximal elbow flexion effort in noninjured subjects.

Adult↗

PubMed1996

An isokinetic study of combined activity of the hip and knee extensors.

The purpose of this study was twofold: to derive isokinetic concentric and eccentric normal strength values obtained during combined activity of the knee and hip extensors and to compare these values with those based on testing of knee extensors only. Fifteen men took part in the study. Combined extension was tested in the supine position with the knee and hip at an initial position of 95 degrees. Knee extension was tested in the seated position with the knee at the same initial position. The range of motion and angular velocities were equal in both configurations: 15 degrees and 8 degrees s(-1) and 15 degrees s(-1) respectively. The average peak force in the CKH mode was close to 10 Nm/kg bw and over 15 Nm/kg bw in the concentric and eccentric contractions respectively, whereas for the knee extensor mode the respective figures were approximately 8 Nm/kg bw and 10 Nm/kg bw. With respect to the same performance parameters, there were low and insignificant correlations between the two modes. RELEVANCE:--Isokinetic testing of knee extensors performance in what is commonly known as single-joint configuration is somewhat limited in its functional scope and, if applied wrongly, is potentially harmful in various dysfunctional states of the knee. On the other hand, multi-joint testing configuration, involving muscles of the hip as well as the knee, is possibly more functional and safe. To assess the muscle performance status of knee patients using the latter mode, data regarding what should be expected from normal individuals is essential. This paper supplements existing material concerning knee and hip extensors and looks into the relationship between the two dynamic contraction modes as well as the association between combined activity and knee extensors only. This association which was found to be very limited indicates that the two configurations reflect different muscle action paradigm and therefore may not be used interchangeably.

Journal Article↗

PubMed1996

Suboptimal muscular performance: measuring isokinetic strength of knee extensors with new testing protocol.

OBJECTIVE: To analyze the relevance of several isokinetics-based variables for the differentiation of suboptimal from optimal knee extension efforts. DESIGN: Three experimental conditions using 4 intermittent-reciprocal concentric (Con) and eccentric (Ecc) efforts at 30/sec and 180/sec. The first condition (MAX) served as the baseline; subjects were instructed to exert maximal Con and Ecc effort. In the second condition (50%MAX), subjects were asked to exert 50% of the strength measured in the first condition based on the initial use of visual feedback. In the third condition (BREP), subjects repeated the second condition but were asked to exert what they thought was a reproducible level of strength. SETTING: A motor performance laboratory in rehabilitation department of a major hospital. PARTICIPANTS: 16 healthy men, ages 21 to 30. RESULTS: Among several parameters that included variability of results and Ecc/Con strength ratios, the one with the highest differentiating power among MAX, 50%MAX, and BREP was the difference between the Ecc/Con ratios at high and low velocities (P < .0006). CONCLUSIONS: Suboptimal knee extension effort can effectively be differentiated from optimal effort in healthy subjects using this protocol.

Adult↗

PubMed1996

Postural stability by computerized posturography in minor head trauma.

Mild head injuries are very common among young children. Often, these injuries are followed by a variety of subjective complaints termed posttraumatic syndrome. Posturography (balance test) was performed immediately after the trauma in 21 children who had sustained mild head injury. Significant difference in performance was observed in head-injured children in all subparts of the test as compared with a control group. We conclude that posturography may serve as a simple cost-effective method in qualifying the posttraumatic imbalance.

Adolescent↗

PubMed1995

Isokinetic strength relationships in shoulder muscles.

The purpose of this study was to extend and refine former findings which related to strength characteristics of the major muscle groups operating on the glenohumeral joint. Based on preliminary isokinetic evaluation of five women and five men, which indicated that overall dominance was not associated with significantly stronger muscles, the dominant shoulders of 30 normal non-athletic subjects, 15 women and 15 men, were tested concentrically and eccentrically, at 60, 120 and 180 degrees /s. The descending order of muscle strength at both contraction modes and for both genders was: extensors, adductors, flexors, abductors, internal rotators and external rotators. Inter-muscle groups' strength correlation coefficients have indicated significant, moderate-fairly strong, relationships in men but not in women. The implications of these findings in terms of testing and shoulder muscle conditioning are discussed. RELEVANCE:--Analysis and interpretation of shoulder muscle dysfunction, and implementation of conditioning protocols, require the availability of normative values pertaining to the common modes of contraction and relative to an acceptable and velocity setup. This study provides a representative data base of normal subjects which may serve for these purposes.

Journal Article↗