Summary

Abdominal muscle strain injuries can occur in high level overhead athletes. Injury laterality is more commonly opposite to the athlete’s dominant upper extremity. Volleyball players were at higher risk of abdominal strain injury compared to athletes participating in other overhead sports.

Abstract

Objective

Little has been reported on the frequency, management and outcomes of abdominal muscle injuries in elite overhead athletes. To report the rate of return to sport following abdominal muscle strain injuries in National Collegiate Athletic Association (NCAA) overhead athletes over a period of 5 years.

Methods

NCAA Division I athletes who participated in overhead sports and received treatment for an abdominal muscle strain injury between years 2015 -2020 were included. Athletes diagnosed with abdominal hernia and/or those who received surgical treatment were excluded. Data collected included the athlete’s age, gender, sport type, mechanism of injury, setting of injury (practice, competition), and treatment modalities. The rate of injury, time and rate of return to sport were recorded. Descriptive statistics were used for analysis (MedCalc). The level of statistical significance was set at 0.05.

Results

A total of 27 overhead athletes (13 females, and 14 males) were included and 31 abdominal muscle strain injuries were reported over the 5-year study period. The average age of the athletes was 21.7+/-2.3 (range: 17-27) years. All but one athlete were right-handed (26/27, 96.2%), and the majority of abdominal muscle injuries were left-sided (20/31, 65%) followed by right-sided (8/31, 26%), and bilateral injuries (3/31, 9%). Abdominal muscle strain injury occurred at a significantly higher rate on the side that was opposite to the athlete’s dominant upper extremity compared to the same side [65.4% and 28.8%, IRR 2.5 (95% CI 1.05-6.5), p=0.023]. The distribution of injury per sport was volleyball (21 injuries); tennis (4 injuries), and baseball (6 injuries). The rate of abdominal muscle strain injury during practice was equal to the rate of this injury during competition (50%). The risk of abdominal muscle strain injury in volleyball was significantly higher compared to other sports combined (68% versus 32%, p= 0.04). The most commonly reported mechanism of abdominal muscle injury in volleyball players was hitting/spiking motion (14/21, 67%). The most commonly observed lesion on Magnetic Resonance Imaging (MRI) was grade 2 strain of the left middle and/or distal rectus abdominis muscle. The majority of injuries (25/31, 81%) were treated with physical therapy with or without nonsteroidal anti-inflammatories (NSAIDs) and six injuries (6/31, 19%) were treated with platelet rich plasma injection (PRP) and physical therapy. The rate of return to sport was 100%. Athletes who received a PRP injection returned to sport faster than the athletes who did not receive a PRP injection; the mean time of return to sport was 2 weeks (range: 1-3) for the PRP group and 3.5 weeks (range: 0-11.5) (p=0.024) for athletes who did not have PRP injection. However, the mean time need for complete resolution of the abdominal muscle strain injury was similar between athletes who received PRP injection and those who did not (9.5 weeks and 10.3 weeks respectively, p=0.875).

Conclusions

Abdominal muscle strain injuries can occur in high level overhead athletes. Injury laterality is more commonly opposite to the athlete’s dominant upper extremity. Volleyball players were at higher risk of abdominal strain injury compared to athletes participating in other overhead sports. The hitting/spiking motion was the most commonly reported mechanism of injury in NCAA Division I volleyball players. Although PRP-injection resulted in slightly faster return to sport compared to physical therapy in overhead athletes with abdominal muscle strain injury, both regimens were equally effective and 100% of the athletes were able to return to sport.