Glenohumeral Internal Rotation Deficit and Muscular Imbalances in Table Tennis Players Using a Horizontal Racquet Grip

Wen-Dien Chang, Sheng-Kuang Wu, Shuya Chen, Yen-Ling Lai, Tong Jing Lim
Purpose:

This study aimed to examine the presence of GIRD in table tennis players, assess associated muscular imbalances, and explore the impact of these imbalances on strength asymmetry in relevant bi-directional movements. 

Methods:

The study evaluated 71 table tennis players, gathering basic physical metrics and using MicroFET3 (Hoggan Health Industries, USA) to measure each player's ROM and muscle strength during isometric contractions. The primary movements assessed included internal rotation (IR), external rotation (ER), horizontal abduction (H-ABD), and horizontal adduction (H-ADD). Participants were categorized into GIRD-positive (GIRD +) and GIRD-negative (GIRD -). Bilateral differences in muscular strength and ROM were compared to identify potential asymmetries. 

Results:

 The GIRD (+) group exhibited a significant deficit in IR ROM on the dominant side compared to the non-dominant side (p0.0001). In contrast, the ER ROM was significantly greater on the dominant side (p=0.0006) for GIRD (+) players. Additionally, the GIRD (+) group showed notable bilateral strength differences in IR and H-ADD (p0.0001 and p=0.0090, respectively). The ER/IR strength ratio also displayed a significant bilateral discrepancy (p=0.0147). However, no significant bilateral strength differences were found for H-ABD and ER. 

Conclusion(s):

Although GIRD is often associated with sports involving repetitive overhead movements like tennis, this study shows that GIRD also affects table tennis players, resulting in substantial IR deficits and muscular imbalances. These imbalances, especially in IR and H-ADD strength, may influence the ER/IR strength ratio, potentially leading to a higher risk of injury. 

Implications:

This study highlights the importance of addressing muscle asymmetries in table tennis players to prevent injuries and optimize performance. Targeted interventions focusing on correcting IR deficits and muscular imbalances may be key in managing GIRD in this athlete population. The study also emphasizes that sports relying heavily on one-sided movements increase the likelihood of muscle strength and ROM imbalances, raising the risk of injury from a clinical sports medicine perspective.

Funding acknowledgements:
National Science and Technology Council (NSTC 113-2425-H-028-003)
Keywords:
Glenohumeral internal rotation deficit
Table tennis
Bilateral asymmetries
Primary topic:
Sport and sports injuries
Second topic:
Musculoskeletal
Did this work require ethics approval?:
Yes
Name the institution and ethics committee that approved your work:
Antai Medical Care Corporation Antai Tian-Sheng Memorial Hospital
Provide the ethics approval number:
19-006-B
Has any of this material been/due to be published or presented at another national or international conference prior to the World Physiotherapy Congress 2025?:
No

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