Side-to-side differences in range of motion, muscle strength, and medial elbow laxity in young baseball players with medial elbow injuries

Abstract

Medial elbow injuries lead to significant performance decrement in baseball.Repetitive throwing alters mechanical physiology. Some of such changes can increase the risk of medial elbow injuries. However, in young baseball players with medial elbow injuries, these changes have not been fully investigated. Thus, the purpose of this study was to investigate the mechanical physiological changes in young baseball players with medial elbow injuries. Sideto-side differences in (1) range of motion (ROM) of shoulder external rotation (ER)/internal rotation (IR), elbow flexion/extension, forearm supination/pronation, trunk rotation, and hip ER/IR; (2) strength of middle trapezius, lower trapezius (LT), and supraspinatus muscles, and shoulder ER/IR; and (3) medial elbow laxity were measured. Side-to-side differences were significant (p < 0.05). ROM of shoulder ER/IR, elbow flexion/extension, forearm pronation, and hip IR on the throwing side were significantly decreased compared to the non-throwing side. Trunk rotation in the direction of the throwing side was significantly decreased compared to the non-throwing side. LT and shoulder IR strength on the throwing side were significantly greater, while shoulder ER strength on the throwing side was significantly weaker than the non-throwing side. Medial elbow joint space of the throwing side was significantly wider than the nonthrowing side. In other measurements, no significant differences were observed between the throwing and non-throwing side. According to our findings, young baseball players with medial elbow injuries experience many side-to-side differences in mechanical physiology. The most interesting finding was that younger players with medial elbow injuries displayed decreased shoulder ER ROM, versus an increase reported in many previous studies.

Does the Record of Physical Fitness Tests Reveal Locomotor Disorders in Children? Relationship Between Records of Physical Fitness Tests and Locomotor Disorder Screenings: Results in Japanese Children

“…In addition to disorders caused by insufficient exercise, excessive exercise can also lead to physical and mental illness, including locomotor disorders (9)(10)(11)(12)(13)(14). As with obesity, locomotor disorders are a global problem, and in 2000, the World Health Organization declared 2000 -2010 as the Bone and Joint Decade (15,16).…”

Physical Fitness Testing and Screening Reveal a Gateway to Identify Locomotive Disorders: Retrospective Study of a Japanese Elementary School Population

“…However, focusing only on improving athletic abilities may result in overuse syndrome, amenorrhea due to excessive weight loss, and other factors such as the ever-increasing prevalence of mental health issues among athletes. 2 - 8…”

“…Locomotive disorders that are problematic in children include calcaneal apophysitis (eg, injury to the inner elbow due to excessive ball throwing), which is known as a type of overuse syndrome. 2 , 5 At the other extreme, weakness of muscles, bones, and ligaments due to lack of exercise 12 is on the rise in Japan and is a major concern because it can prevent normal growth and lower the quality of life. Thus, excessive or too little exercise can lead to pediatric locomotive disorders and poses a future health crisis for growing children.…”

“…However, focusing only on improving athletic abilities may result in overuse syndrome, amenorrhea due to excessive weight loss, and other factors such as the ever-increasing prevalence of mental health issues among athletes. [2][3][4][5][6][7][8] By contrast, in Japan, children who exercise and those who do not are increasingly polarized. According to an exercise habits survey conducted by The Ministry of Education, Culture, Sports, Science, and Technology in Japan in 2018, the percentage of female students in eighth grade who achieved less than 60 minutes of exercise per week (apart from physical education class time) was 19.4%, of which 13.6% did not partake in any exercise activity at all.…”

“…10,11 Locomotive disorders that are problematic in children include calcaneal apophysitis (eg, injury to the inner elbow due to excessive ball throwing), which is known as a type of overuse syndrome. 2,5 At the other extreme, weakness of muscles, bones, and ligaments due to lack of exercise 12 is on the rise in Japan and is a…”