Assessment of isokinetic muscle function in Korea male volleyball athletes

THE RELATIONSHIP BETWEEN TRUNK MUSCLE STRENGTH AND PELVIC OSCILLATION IN HEALTHY ADULTS

Purpose: Pelvis and trunk structure are body segments that are integrated with each other. Collaboration between pelvic mobility and trunk muscles plays a significant role in walking and energy consumption. The aim of this study is to investigate the relationship between trunk muscle strength and pelvic oscillations. Methods: Twenty-eight healthy individuals volunteered for the study (16 women, 12 man; mean age 24.46 ± 2.97 yrs., height 172.03 ± 9.41cm, weight 67.78 ± 16.31 kg). Gait characteristics and pelvic oscillation were measured by using wireless tri-axial accelerometer. Trunk muscle strength were evaluated with Isokinetic Dynamometer (Cybex Humac Norm Testing & Rehabilitation System, USA). The trunk extensors and flexors were tested concentrically at 60°s. Statistically, the direction and level of the relationship were examined by using Spearman Correlation Analysis. Results: Correlation analysis showed significant relationships between concentric strength of trunk flexion and anterior-posterior pelvic tilt (r=-0.419), lateral pelvic tilt (r=-0.768) and hip rotation (r=-0.382). A statistically significant relationship was not observed between concentric strength of trunk extension and anterior-posterior pelvic tilt, hip rotation (p>0.05). Conclusion: The current study reports that trunk muscle strength is associated with pelvic oscillations. Also, these results suggest that maintaining optimal levels of trunk muscle strength prepares a healthful basis for the pelvis during walking. Therefore, it contributes to the prevention of possible pathologies related to lower extremity. Although trunk muscle strength and pelvic mobility are important determinants of gait, these factors are insufficient to evaluate the whole gait cycle and energy expenditure of individuals.

Isokinetic strength of shoulder rotator muscles in powerlifters: correlation between isometric and concentric muscle actions

BACKGROUND

Isokinetic strength has been useful to assess muscle function related to sports and prevent injuries. The present study measured the isokinetic isometric and concentric shoulder rotators strength, agonist/antagonist ratio, and examined the relationships between isometric and concentric peak torque, and agonist/antagonist ratio in powerlifters compared to a control group.

METHODS

The participants were divided into two groups: powerlifters group (n=14) and physically active group (n=9). Participants' were evaluated on isokinetic dynamometer for isometric, and concentric (two velocities, 60°/s and 180°/s) strength of shoulder external (ER) internal rotation (IR). Isometric contractions lasted 10 seconds, and concentric modes were 5 repetitions.

RESULTS

Bilateral significant differences, between dominant and non-dominant side, were found in ER peak torque at isometric mode in powerlifters group (p=0.021). Powerlifters showed higher IR peak torque at isometric mode in dominant (p=0.040) and non-dominant side (p=0.014) than physically active group. Pearson correlations between isometric peak torque and concentric velocities ranged between 0.49 and 0.89 for powerlifters group, and between 0.73 and 0.93 for physically active group. For agonist/antagonist ratio, pearson correlation ranged between 0.47 and 0.83 for powerlifters group, and between 0.48 and 0.86 for physically active group.

CONCLUSIONS

The bilateral differences in ER movement at isometric mode in powerlifters suggest that exercises for shoulder rotators must be included on training for joint safety and balance between sides despite isometric shoulder rotators strength in powerlifters was higher than physically active individuals. Results presented positive correlation between both muscle actions, isometric and concentric, in peak torque and agonist/antagonist ratio.

The Impact of Tennis and Golfer's Elbow on Shoulder External Rotators and Abductors' Peak Torque

CONTEXT

Upper limb activities require a repetitive movement of the shoulder external rotator and abductor muscles. The malfunction of the proximal part of the upper limb kinetic chain tends to change the mechanics of the distal part and increase the risk of injuries.

OBJECTIVES

To compare the normalized eccentric peak torque (NEPT) of the shoulder external rotator and abductor muscles among healthy athletes and those with tennis elbow and golfer's elbow.

DESIGN

An experimental cross-sectional study.

SETTING

Isokinetic laboratory, Faculty of Physical Therapy, Cairo University.

PARTICIPANTS

A total of 30 male athletes participated voluntarily in this study.

INTERVENTION

Participants were distributed into 3 groups: healthy group, tennis elbow group, and golfer's elbow group.

MAIN OUTCOME MEASURES

NEPT of shoulder abductors and external rotators. The Biodex Isokinetic Dynamometer was used to measure the variables of interest.

RESULTS

There was a significant increase in the NEPT of shoulder abductors and external rotators in healthy control group compared with both tennis elbow and golfer's elbow groups at an angular velocity of 60°/s (P < .05). Moreover, there was a significant increase in the NEPT of shoulder external rotators and abductors at an angular velocity of 120°/s in healthy control group compared with tennis elbow group and in golfer's elbow group compared with tennis elbow group (P < .05).

CONCLUSION

Tennis elbow and golfer's elbow are associated with decreased NEPT of shoulder external rotators and abductors compared with those of healthy athletes. This tends to decrease the external stability of the shoulder joint and put high stress on the distal joints of the upper kinetic chain.

Characteristics of upper extremity's muscle strength in Turkish national wheelchair basketball players team

The objective of this study was to reveal characteristics of muscle strength of upper extremities of wheelchair (WC) basketball players and to ensure more-specific training program preparation. Isokinetic muscle strength of 12 WC basketball players were assessed by ISOMED 2000 device. The assessment protocol was evaluated at 60°/sec velocity with 5 times repeated force and at 240°/sec with 15 times repeated force. This protocol was carried out individually for shoulder flexion-extension and wrist flexion-extension movements at the right and left extremities. The flexion/extension ratio was determined to be outside of the ratios accepted as normal for primarily shoulder joint and for wrist joint. The extension movement was stronger than flexion movement in the shoulders at both velocities and the flexion movement was stronger than ex-tension movement in the wrist. The repeat times where the peak torque occurred were 2–3 repeats at 60°/sec velocity during flexion and extension movements for the wrist and shoulders, and the peak torque occurred at an average of 5–6 repeats in the shoulders at 240°/sec velocity and it occurred at 3–4 repeats in the wrist. The angles where the peak torque of the shoulder flexion and extension occurred varied between 80°–115° at both velocities, and it varied between 5°–30° angles for the wrist. As this study revealed, determination of muscle strength characteristics of WC athletes and especially using objective isokinetic devices will guide the planning of the appropriate training and exercise programs and preventing sports injuries in long term.