Reliability of the Modified CKCUEST and correlation with shoulder strength in adolescent basketball and volleyball players.

BACKGROUND: Physical performance tests provide a more complete picture of the functional status of the athlete's upper extremity. OBJECTIVES: The primary purpose was to evaluate the reliability of the Modified Closed Kinetic Chain Upper Extremity Stability Test (MCKCUEST) in adolescent volleyball and basketball players. The secondary objective was to evaluate the relationship between the MCKCUEST and shoulder rotation isometric strength in this population. METHODS: Seventy-three healthy basketball (n=39) and volleyball (n=34) players participated to establish the reliability and correlations of the MCKCUEST. We used a two-session measurement design to evaluate the reliability of the MCKCUEST. Shoulder rotation isometric strength was performed to determine relationships with the MCKCUEST. RESULTS: The intraclass correlation coefficients (ICC2,1) for intra-session reliability of the MCKCUEST ranged from 0.86 to 0.89, and the between days test-retest reliability (ICC3,1) was 0.93. The standard error of measurement (1 touch) and the minimal detectable change (3 touches) showed clinically acceptable absolute reliability values. A weak correlation was found between the MCKCUEST power score and shoulder rotation isometric strength (r values between 0.3 and 0.4). CONCLUSIONS: Results demonstrated good to excellent relative reliability and clinically acceptable absolute reliability values for the MCKCUEST on adolescent basketball and volleyball athletes. Performances on the MCKCUEST were weakly associated with shoulder rotation strength.

The challenge of the sporting shoulder: From injury prevention through sport-specific rehabilitation toward return to play.

Shoulder injuries and sports-related shoulder pain are substantial burdens for athletes performing a shoulder loading sport. The burden of shoulder problems in the athletic population highlights the need for prevention strategies, effective rehabilitation programs, and a individually based return-to-play (RTP) decision. The purpose of this clinical commentary is to discuss each of these 3 challenges in the sporting shoulder, to assist the professional in: (1) preventing injury; (2) providing evidence-based practice rehabilitation and; (3) to guide the athlete toward RTP. The challenges for injury prevention may be found in the search for (the interaction between) relevant risk factors, develop valid screening tests, and implement feasible injury prevention programmes with maximal adherence from the athletes. Combined analytical and functional testing seems mandatory screening an athlete's performance. Many questions arise when rehabilitating the overhead athlete, from exercise selection, over the value of stretching, toward kinetic chain implementation and progression to high performance training. Evidence-based practice should be driven by the available research, clinical expertise and the patient's expectations. Deciding when to return to sport after a shoulder injury is complex and multifactorial. The main concern in the RTP decision is to minimize the risk of re-injury. In the absence of a "gold standard", clinicians may rely on general guidelines, based on expert opinion, regarding cutoff values for normal range of motion, strength and function, with attention to risk tolerance and load management.

The Effects of Eccentric Training on Biceps Femoris Architecture and Strength: A Systematic Review With Meta-Analysis.

OBJECTIVE: To determine the effects of an eccentric hamstrings strength-training program, performed for at least 4 weeks by healthy adults, on muscle architecture and eccentric strength. DATA SOURCES: A systematic search was performed up to October 2018 in the following electronic databases: PubMed, PEDro, CINAHL and SPORTDiscus. Combinations of the following search terms were used: eccentric strength training, eccentric loading, nordic hamstring, hamstring strength, fascicle length, pennation angle, muscle thickness, muscle architecture, biceps femoris long head, biceps femoris, and hamstring muscles. STUDY SELECTION: Included articles were randomized controlled trials that allowed comparisons between isolated eccentric strength training of the biceps femoris muscle and other programs. DATA EXTRACTION: Data from the included studies were extracted by 2 independent reviewers. These data included the study design, participant characteristics, inclusion and exclusion criteria of clinical studies, exercise and intervention characteristics, outcome measures, and the main results of the study. When meta-analysis was possible, we performed quantitative analysis. Ten randomized controlled trials were included. DATA SYNTHESIS: Limited to moderate evidence indicated that eccentric strength training was associated with an increase in fascicle length (mean difference [MD] = 1.97; 95% confidence interval [CI] = 1.48, 2.46), an increase in muscle thickness (MD = 0.10; 95% CI = 0.06, 0.13), and a decrease in pennation angle (MD = 2.36; 95% CI = 1.61, 3.11). Conflicted to moderate evidence indicated that eccentric hamstrings strength was increased after eccentric strength training compared with concentric strength training (standardized mean difference [SMD] = 1.06; 95% CI = 0.26, 1.86), usual level of activity (SMD = 2.72; 95% CI = 1.68, 3.77), and static stretching (SMD = 0.39; 95% CI = -0.97, 1.75). CONCLUSIONS: In healthy adults, an eccentric strength-training program produced architectural adaptations on the long head of the biceps femoris muscle and increased eccentric hamstrings strength.

The Self-Assessment Corner for Shoulder Strength: Reliability, Validity, and Correlations With Upper Extremity Physical Performance Tests.

CONTEXT: Rotator cuff weakness and rotation ratio imbalances are possible risk factors for shoulder injury among overhead athletes. In consensus statements, organizations have highlighted the importance of a screening examination to identify athletes at risk of injury. The screening should be portable and designed to be feasible in many different environments and contexts. OBJECTIVE: To evaluate the reliability and validity of the Self-Assessment Corner (SAC) for self-assessing shoulder isometric rotational strength and examining whether performance on 2 physical performance tests was correlated with isometric shoulder rotational strength using the SAC in handball players. DESIGN: Cross-sectional study. SETTING: Sport setting. PATIENTS OR OTHER PARTICIPANTS: A first sample of 42 participants (18 men, 24 women) was recruited to determine the reliability and validity of the SAC. In a second sample of 34 handball players (18 men, 16 women), we examined correlations between physical performance tests and the SAC. MAIN OUTCOME MEASURE(S): The SAC was used to measure isometric rotational strength with the upper extremity at 90° of abduction in the frontal plane and 90° of external rotation and the elbow flexed to 90° with neutral rotation of the forearm. The SAC findings were compared with those from manual testing. Results from the seated medicine ball throw (SMBT) and closed kinetic chain upper extremity stability test (CKCUEST) were used to establish relationships with the SAC. We calculated intraclass correlation coefficients to determine relative reliability and used standard error of measurement and minimal detectable change to quantify absolute reliability. Relationships among the different strength-testing procedures and with the physical performance tests were determined using the Pearson product moment correlation coefficient (r) or Spearman rank correlation coefficient (rs). RESULTS: We observed good to excellent reliability (intraclass correlation coefficient [2,k] range = 0.89 to 0.92). The standard error of measurement varied from 3.45 to 3.48 N. The minimal detectable change with 95% confidence intervals ranged from 8.06 to 8.13 N. Strong correlations were present among strength procedures (r = 0.824, rs range = 0.754-0.816). We observed moderate to strong correlations between the CKCUEST findings and rotational strength (r range = 0.570-0.767). Moderate correlations were found between rotational strength and SMBT (r range = 0.573-0.626). CONCLUSIONS: The SAC is a clinically applicable and standardized protocol for self-assessing rotational strength in young healthy adults without pathologic conditions. Performance on the SMBT and CKCUEST may be valuable as a screening tool to further assess shoulder strength.