Isokinetic Assessment of Shoulder Joint Strength Ratios in Male Recreational Weightlifters: A Cross-Sectional Study

Osama R Abdelraouf; Marwa Y Ebrahim; Amr A Abdel-Aziem; Soheir M Abdel-Rahman; Ahmed S Yamani; Ahmad A El Askary

doi:10.1155/2022/6106943

Isokinetic Assessment of Shoulder Joint Strength Ratios in Male Recreational Weightlifters: A Cross-Sectional Study

Appl Bionics Biomech. 2022 Jun 13:2022:6106943. doi: 10.1155/2022/6106943. eCollection 2022.

Authors

Osama R Abdelraouf¹, Marwa Y Ebrahim², Amr A Abdel-Aziem³, Soheir M Abdel-Rahman², Ahmed S Yamani², Ahmad A El Askary⁴

Affiliations

¹ Physical Therapy program, Batterjee Medical College, Jeddah 21442, Saudi Arabia.
² Department of Biomechanics, Faculty of Physical Therapy, Cairo University, Giza 12613, Egypt.
³ Department of Physical Therapy, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
⁴ Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.

Abstract

Background: Isokinetic strength imbalance is a risk factor for movement dysfunctions and injuries related to shoulder complex. The effects of recreational weightlifting on developing the imbalances between the shoulder muscles are not yet known.

Objectives: To investigate the isokinetic concentric shoulder muscle strength values (peak torque normalized to body weight) in recreational weightlifters (RWL) and to compare the shoulder muscles agonist/antagonist ratios with nonweightlifters.

Methods: Thirty male RWL with mean age, weight, height, and body mass index (BMI) of 21.56 years, 84.25 kg, 175.34 cm, and 26.51 kg/m², respectively, matched with nonweightlifters served as a control group. The normalized concentric peak torque values of shoulder flexors, extensors, abductors, adductors, and internal and external rotators were measured at angular velocity 120°/sec by using Biodex isokinetic system. Moreover, the agonist/antagonist strength ratio for all muscle groups were calculated.

Results: The normalized peak torques of RWL group were significantly greater than the control group (p < 0.05). The abductor/adductor and external rotator/internal rotator ratios of the RWL were significantly lower than the control group (p = 0.008 and 0.009, respectively). Conversely, there was no significant difference between both groups in relation to the flexor/extensor ratio (p = 0.259).

Conclusion: These results suggested that the recreational weightlifting exercises place trainees at risk of muscle imbalances. Therefore, the restoration of a normal concentric abductor/adductor and external rotator/internal rotator strength ratios may decrease the risk of possible shoulder injury.