Electromyographic evaluation of upper limb muscles involved in armwrestling sport simulation during dynamic and static conditions

Fractures of the humeral shaft caused by arm wrestling: a systematic review

Background

Arm wrestling is a popular sport/game that may result in various injuries. The most common arm wrestling injury in adults is humeral shaft fracture. This study aimed to elucidate the current understanding of humeral shaft fracture caused by arm wrestling and propose the possible mechanism.

Methods

The PubMed and Web of Science databases were searched using the terms "arm wrestling" and "humeral fracture" as well as "sports" and "humeral fracture" in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The inclusion criteria were English full-text articles and notable full-text articles in other languages concerning humeral shaft fracture caused by arm wrestling that described the patients' characteristics and presented adequate images or a detailed description of the fracture to confirm the fracture details. The exclusion criterion was a lack of appropriate images or detailed description of the fracture. Fifty-seven studies were identified. The patients' demographics were evaluated. The details of fractures, primary radial nerve palsy, match status, provided fracture treatment, and outcomes were evaluated using the chi-squared test. The relationship between fracture site and the patient's age was analyzed using Student's t-test.

Results

One hundred fifty-three patients, 82% of whom were males aged 15-34 years, were identified. With only a few exceptions, almost all patients were injured in recreational matches. The injured limb was the right arm in 65% of patients (n = 141). The patient's physical characteristics, the opponent's physical characteristics compared with those of the patient, and the match status at the time of injury varied between cases. Among the 46 patients with known match details, all were injured when one of the wrestling opponents suddenly added more force in an attempt to change the match status. The fracture configuration was spiral in all cases, and 48% of fractures had an associated medial butterfly fragment. The fracture site was the distal third or the junction between the distal and middle thirds in 90% of cases. Although primary radial nerve palsy was recognized in 19 of 103 patients (18.4%), all resolved spontaneously.

Conclusion

Although humeral shaft fracture caused by arm wrestling occurred mostly in male players aged 15-34 years, this injury may affect any player regardless of the match status, player's and opponent's physical characteristics, and age. The direct cause is torsional force generated by the internal rotators. A sudden change from concentric to eccentric contraction of the internal rotators is likely to cause fracture.

Fracture-Separation of the Medial Humeral Epicondyle Caused by Arm Wrestling: A Systematic Review

Background:

Arm wrestling is a popular sport in which various injuries have occurred, even in children.

Purpose:

To analyze reported fracture-separation of the medial humeral epicondyle (MHE) caused by arm wrestling to determine its mechanism and provide a current overview.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed and Web of Science databases were searched using the terms “arm wrestling” and “humeral fracture” or “medial humeral epicondyle fracture”; and “sports” and “humeral fracture” or “medial humeral epicondyle fracture,” following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were English full-text articles on arm wrestling–induced MHE fracture that described patient characteristics and presented appropriate images. Studies with a lack of appropriate images or detailed description of the injury situation were excluded. The patient characteristics were evaluated, and the ratios of treatment selection and outcomes were evaluated using the chi-square test.

Results:

Included were 27 studies with a total of 68 patients, all boys with a mean age of 14.6 ± 1.24 years (based on n = 65, with 3 patients excluded from this calculation as no definitive age was provided). Boys aged 14 to 15 years accounted for 72% (49/68) of the cases. Fracture occurred suddenly during arm wrestling in 63 boys, while the other 5 boys experienced antecedent medial elbow pain. The match status at the time of injury, provided for 46 patients, was varied. In 31 boys with known match details, injury occurred when a participant suddenly added more force to change the match status. Eight patients displayed anterior and/or proximal displacement of the MHE fragment. Treatment was nonoperative in 25 patients and operative in 38 patients (n = 63, excluding 5 unknown patients). In 35 patients followed up for ≥3 months (mean, 17.6 ± 12.3 months), outcomes were not significantly different between the operative and nonoperative groups.

Conclusion:

MHE fracture-separation caused by arm wrestling occurred mostly in boys aged 14 to 15 years regardless of the match status. The likely direct cause is forceful traction of the attached flexor-pronator muscles. A relative mechanical imbalance during adolescence may be an underlying cause. A sudden change from concentric to eccentric contraction of the flexor-pronator muscles increases the likelihood of fracture occurrence.

Humeral Shaft Fracture Sustained During Arm Wrestling with Review of Factors Contributing to its Causation

Introduction:

Humeral shaft fractures are the most common injury sustained in arm wrestling, and its various biomechanical, anatomical, kinematic and electromyographic aspects have been studied and reported. We present a series of six cases of humeral shaft fractures in the arm wrestlers and a review of basic science studies to determine the factors contributing to their causation.

Materials and methods:

Six humeral shaft fractures associated with arm wrestling were treated between December 2018 and January 2020. The medical records and radiographs were retrospectively reviewed. In addition, the characteristics of the patients, their opponents, and the fractures were noted in a pre-designed data sheet.

Results:

There were six men with an average age of 27.5 years (SD ± 8.9). All were amateurs who were occasional arm wrestlers. Three fractures each were sustained in the sitting and standing position, four in the losing phase, one in the winning phase, and one in the stalling phase. The dominant side humerus was involved in all but one case. The fracture types were 12-A1 (n=4); 12-B1 (n=1); 12-A2 (n=1). Three fractures were treated by open reduction and internal fixation, while three were treated conservatively with satisfactory healing.

Conclusion:

Humeral shaft fractures in arm wrestling are common in amateurs. There is no association of the fracture with the position of the players or the phase of the match. However, arm wrestlers should be aware of this complication and should receive proper guidance to reduce the risk of humeral shaft fractures.