Shoulder Rotation Range of Motion and Serve Speed in Adolescent Male Volleyball Athletes: A Cross-Sectional Study

BackgroundThrowing athletes present alterations in shoulder rotation range of motion (ROM), but not much is known about the relationship between these alterations and performance measurements in volleyball practitioners.PurposeTo compare the passive ranges of motion of internal rotation (IR), external rotation (ER), and total rotation motion (TRM) of the shoulder in dominant and nondominant limbs of young volleyball athletes and to investigate their relationship with ball speed during serves with and without precision (inside and outside court, respectively). The possible association of anthropometrics and competitive practice time with these velocities was also investigated.Study DesignCross-sectional study.MethodsFifty-seven male volleyball athletes (mean age 17.11 ± 1.88 y; weight 74.68 ± 9.7 kg; height 1.87 ± 0.09 cm) were evaluated for shoulder IR and ER with a bubble goniometer and serve speed inside and outside court was measured with a radar gun. Simple and multiple regression analyses were applied to investigate associations of ROM, anthropometrics, and competitive practice time with serve speed.ResultsDominant shoulders had diminished IR ROM compared to nondominant shoulders (59.1º ± 16.7º vs 66.4º ± 16.9º; p < 0.001) as well as diminished TRM (173.5º ± 31.8º vs 179.1º ± 29.9º; p < 0.001). Simple regression showed negative association between dominant ER and serve speed outside the court (p = 0.004). Positive associations existed between age and serve speed in both conditions (p < 0.001), BMI and speed inside (p = 0.009) and outside the court (p = 0.008), and between competitive practice time and speed inside (p = 0.008) and outside court (p = 0.003). However, multiple analysis confirmed only age (p < 0.001) and BMI to be associated with ball velocities (inside court p = 0.034; outside court p = 0.031).ConclusionThe results of this study demonstrated that young volleyball athletes presented lower IR and TRM of the shoulder in the dominant upper limb. Age and BMI were directly associated with ball velocities when serving. Passive rotation ROM did not have a relationship with this performance measurement.Level of Evidence3b     

Safety and Effectiveness of a Perturbation-based Neuromuscular Training Program on Dynamic Balance in Adolescent Females: A Randomized Controlled Trial

BackgroundAdolescent females are at much greater risk for ACL injury than their male counterparts when participating in the same sports. Preventative and pre-operative rehabilitation neuromuscular (NM) exercise programs are often recommended to improve knee function and reduce injury rates. The effectiveness of perturbation-based NM training program has been established in an adult population but has yet to be investigated in the at-risk adolescent female population.PurposeTo determine the effectiveness of a perturbation-based NM exercise program in a group of physically active adolescent females.Study DesignProspective randomized trial.MethodsTwenty-four healthy and an exploratory group of 10 ACL-injured females (ages 12-18) were equally randomized into a perturbation-based NM training or control group and evaluated before and after a five-week intervention period. The primary outcome of dynamic balance was measured using the Y-Balance test (YBT); secondary outcome measures included lower limb strength, proprioception, and flexibility.ResultsThe perturbation-based NM training intervention was safely completed by all participants but had no significant effect on YBT scoring, lower limb strength, proprioception or flexibility in either the healthy or ACL-injured groups.ConclusionsPerturbation-based NM training is safe, but may offer little preventative benefit for healthy or pre-operative rehabilitation benefit for ACL-injured adolescent females. Future research should examine whether the effectiveness of perturbation-based NM training is influenced by the length of the training intervention, training intensity, or when it is combined with other forms of prophylactic or pre-surgical rehabilitation frequently used with at-risk adolescent females who regularly participate in sport.Level of EvidenceLevel 3.     

Passive Rotation Range of Motion and Shoulder Subluxation: A Comparative Study

Background

Conflicting reports of range of motion (ROM) findings exist related to shoulder instability. Knowledge of range of motion findings among individuals with shoulder subluxation may aid in diagnosis and facilitate appropriate management.

Purpose

The purpose of this study was to compare passive rotation ROM and determine if a symptom-provoking activity alters ROM between patients with shoulder subluxations and healthy controls.

Methods

Seventeen symptomatic patients with shoulder subluxations and 14 healthy controls between the ages of 18 and 35 years were recruited. Lateral and medial rotation ROM measures were taken using a universal goniometer. Symptoms were assessed using a 10cm visual analog scale (VAS). Each group performed a symptom-provoking activity, and VAS and ROM measures were repeated.

Results

A two-factor analysis of variance with repeated measures on pre/post activity demonstrated lower medial rotation measures for the instability group, but no differences for lateral rotation or total range (p < 0.05). A “warm-up” effect was noted, with greater ROM found in each group post activity, with a greater increase noted among controls. Analysis of the ratio of lateral rotation to medial rotation ROM found a significantly greater ratio in the instability group. VAS pain scores were greater in the instability group.

Conclusion

Shoulder subluxation is not necessarily associated with increased rotation ROM, therefore total ROM findings should not be used to screen for instability. Imbalances in rotation ROM may be associated with symptomatic shoulder instability and may have implications for treatment.