The Test-Retest Reliability of Bilateral and Unilateral Force Plate-Derived Parameters of the Countermovement Push-Up in Elite Boxers.

CONTEXT: Maximal power describes the ability to immediately produce power with the maximal velocity at the point of release, impact, and/or take off-the greater an athlete's ability to produce maximal power, the greater the improvement of athletic performance. In reference to boxing performance, regular consistent production of high muscular power during punching is considered an essential prerequisite. Despite the importance of upper limb power to athletic performance, presently, there is no gold standard test for upper limb force development performance. OBJECTIVE: To investigate the test-retest reliability of the force plate-derived measures of countermovement push-up in elite boxers. DESIGN: Test-retest design. SETTING: High Performance Olympic Training Center. PARTICIPANTS: Eighteen elite Olympic boxers (age = 23 [3] y; height = 1.68 [0.39] m; body mass = 70.0 [17] kg). INTERVENTION: Participants performed 5 repetitions of countermovement push-up trials on FD4000 Forcedeck dual force platforms on 2 separate test occasions 7 days apart. MAIN OUTCOME MEASURES: Peak force, mean force, flight time, rate of force development, impulse, and vertical stiffness of the bilateral and unilateral limbs from the force-time curve. RESULTS: No significant differences between the 2 trial occasions for any of the derived bilateral or unilateral performance measures. Intraclass correlation coefficients indicated moderate to high reliability for performance parameters (intraclass correlation coefficients = .68-.98) and low coefficient of variation (3%-10%) apart from vertical stiffness (coefficient of variation = 16.5%-25%). Mean force demonstrated the greatest reliability (coefficient of variation = 3%). In contrast, no significant differences (P < .001) were noted between left and right limbs (P = .005-.791), or between orthodox or southpaw boxing styles (P = .19-.95). CONCLUSION: Force platform-derived kinetic bilateral and unilateral parameters of countermovement push-up are reliable measures of upper limb power performance in elite-level boxers; results suggest unilateral differences within the bilateral condition are not the norm for an elite boxing cohort.

The epidemiology of injuries in English professional squash; A retrospective analysis between 2004 and 2015.

OBJECTIVES: There have been no reported comprehensive injury reports of elite squash players during training and competition. We reviewed the reported injuries during training and competition during 2004-2015. DESIGN: A retrospective analysis of the injury records was carried out between the periods of 2004-2015 of all athletes who were funded by England squash. SETTING: In competition and training. PARTICIPANTS: Elite England Squash players, 67 athletes (45 males, 22 females), with an age range of 18-35 (average 25 years). MAIN OUTCOME MEASURES: The players' age, sex, location, region affected and description of each injury. RESULTS: Injury data was collected from The main region of the body injured was the lower limb: 76.48%, broken down further as: ankle/heel - 20.81%; thigh - 12.69%; knee -10.83%; hip/groin - 9.48%; buttock - 7.45%; lower leg - 7.61%; and foot - 7.61%. CONCLUSIONS: Professional squash players have a high incidence of lower limb injuries from participation in their sport. The majority of these injuries occur around the ankle and heel, and are of soft tissue in nature.

The Test-Retest Reliability of Force Plate-Derived Parameters of the Countermovement Push-Up as a Power Assessment Tool.

CONTEXT: Muscular power output of the upper limb is a key aspect of athletic and sporting performance. Maximal power describes the ability to immediately produce power with maximal velocity at the point of release, impact, or takeoff, with research highlighting that the greater an athlete's ability to produce maximal power, the greater the improvement in athletic performance. Despite the importance of upper-limb power for athletic performance, there is presently no gold-standard test for upper-limb force development performance. OBJECTIVE: The aim of this study was to investigate the test-retest reliability of force plate-derived measures of the countermovement push-up in active males. DESIGN: Test-retest design. SETTING: Controlled laboratory. PARTICIPANTS: Physically active college athletes (age 24 [3] y, height 1.79 [0.08] m, body mass 81.7 [9.9] kg). INTERVENTION: Subjects performed 3 repetitions of maximal effort countermovement push-up trials on Kistler force plates on 2 separate test occasions 7 days apart. MAIN OUTCOME MEASURES: Peak force, mean force, flight time, rate of force development, and impulse were analyzed from the force-time curve. RESULTS: No significant differences between the 2 trial occasions were observed for any of the derived performance measures. Intraclass correlation coefficient and within-subject coefficient of variation calculations indicated performance measures to have moderate to very high reliability (intraclass correlation coefficient = .88-.98), coefficient of variation = 5.5%-14.1%). Smallest detectable difference for peak force (7.5%), mean force (8.6%), and rate of force development (11.2%) were small to moderate. CONCLUSION: Force platform-derived kinetic parameters of countermovement push-up are reliable measurements of power in college-level athletes.

The Inter-rater Reliability of the Functional Movement Screen Within an Athletic Population Using Untrained Raters.

Elias JE. The inter-rater reliability of the functional movement screen within an athletic population using untrained raters. J Strength Cond Res 30(9): 2591-2599, 2016-The functional movement screen (FMS) is a commonly used screening tool designed to identify restrictions to movement patterns and increased injury risk using 7 predesigned tests. The purpose of this study was to analyze the inter-rater reliability of scoring of the FMS using a group of "untrained" subjects. Additionally, the study also examined if clinical experience level had any effect on reliability. Twenty fully qualified Physiotherapists working at the English Institute of Sport, with elite athletes, volunteered to participate in the study. The group comprised both level 2 and level 3 physiotherapists based on clinical experience levels. Five elite athletes, free from injury, were recruited and videoed completing 6 of the 7 FMS tests using a 3 camera system. The videos were scored by each Physiotherapist using the standardized scoring sheet, as developed by Cook et al. Each practitioner marked each athlete completing the 6 tests. The total scores were calculated for each athlete (maximum score of 18). The inter-rater reliability of the test was shown to be high, intraclass coefficient 0.906. An independent t test showed no significant differences between the level 2 and level 3 practitioners in the total scores (p = 0.502). The results of the test indicate that the FMS is a reliable screening tool when used by untrained practitioners in determining faulty movement patterns and that clinical experience level does not affect the reliability, therefore it may be a useful tool in the screening of athletic populations.

Shoulder injuries in professional rugby: a retrospective analysis.

BACKGROUND: In the literature, little is known about the level and pattern of rugby injuries. Of the shoulder injuries reported, 51% of these are caused during a tackle, and 65% of all match injuries affected the shoulder. OBJECTIVE: The study aims to describe a sport-specific unique intra-articular shoulder pathology of professional rugby players, who presented with persistent pain and dysfunction despite physiotherapeutic treatment and rest. METHOD: This study is a retrospective analysis set at a university sports medicine clinic. Eighty-seven professional rugby players, referred by their professional medical team since they could no longer play, underwent shoulder arthroscopy between June 2001 and October 2007 due to persistent shoulder pain and dysfunction. All were full-time professional male rugby union and rugby league players. They all had failed conservative treatment for their complaint, and the diagnosis was unclear. Arthroscopic findings were used as a measure of main outcome. RESULTS: The primary mechanism of injury was reported as direct tackling (56%; n = 49) followed in succession by falling onto the arm (10%; n = 8). However, in 30% of the cases, no definite injury could be recalled. The main operative finding was that most patients exhibited multiple shoulder pathologies, with 75% of cases presenting with two or more pathologies. A superior labrum anterior to posterior (SLAP) lesion was evident at arthroscopy in 72 of the 87 cases (83%), while rotator cuff tears were evident in 43% of cases (n = 37). One-third of all cases had a Bankart tear (n = 29), despite none of them reporting previous dislocations, while other labral tears, excluding SLAP tears, to the inferior or posterior labrum were present in 34% (n = 30) of the cohort. CONCLUSIONS: Repeated tackling, which is clearly rugby specific, is most likely to be responsible for most of these shoulder injuries, which upon arthroscopic examination, showed signs of mixed pathology. We suggest that an early arthroscopic investigation is valuable in this population in order to confirm treatable diagnosis on the painful shoulder and expedite a safe return to play.

A comparison of the musculoskeletal assessments of the shoulder girdles of professional rugby players and professional soccer players.

OBJECTIVE: To identify posture types that exist in professional rugby players, and compare them with a population of non-overhead athletes in order to identify possible relationships towards the potential for shoulder injuries. DESIGN: Observational design Setting: Sports Medicine Clinic Participants: Convenience sample Methodology: Static assessment of posture was carried out in standing, active and passive range of glenohumeral motion, and isometric strength was carried out in accordance with previously recorded protocols. INTERVENTIONS: Nil Outcome Measures: Observational classification of posture, active and passive range of glenohumeral joint range of motion, isometric strength of selected muscle groups, selected muscle flexibility and Hawkins and Neer impingement tests. RESULTS: There was a significant difference on range of motion between the two groups (0.025-0.000), isometric middle (0.024-0.005), and lower trapezius (0.01-0.001). CONCLUSION: There were significant differences between strength and flexibility of muscles around the shoulder girdle between professional rugby players and a control group of professional non-overhead athletes.

Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

BACKGROUND: The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. METHODS: Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). RESULTS: Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the non-injured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. CONCLUSIONS: This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases.

Clinical and arthroscopic findings in recreationally active patients.

OBJECTIVE: To examine the diagnostic accuracy of standard clinical tests for the shoulder in recreational athletes with activity related pain. DESIGN: Cohort study with index test of clinical examination and reference standard of arthroscopy. SETTING: Sports Medicine clinic in Sheffield, U.K. PARTICIPANTS: 101 recreational athletes (82 male, 19 female; mean age 40.8 +/- 14.6 years) over a six year period. INTERVENTIONS: Bilateral evaluation of movements of the shoulder followed by standardized shoulder tests, formulation of clinical diagnosis and shoulder arthroscopy conducted by the same surgeon. MAIN OUTCOME MEASUREMENTS: Sensitivity, specificity, likelihood ratio for a positive test and over-all accuracy of clinical examination was examined retrospectively and compared with arthroscopy. RESULTS: Isolated pathology was rare, most patients (72%) having more than one injury recorded. O'Brien's clinical test had a mediocre sensitivity (64%) and over-all accuracy (54%) for diagnosing SLAP lesions. Hawkins test and Jobe's test had the highest but still not impressive over-all accuracy (67%) and sensitivity (67%) for rotator cuff pathology respectively. External and internal impingement tests showed similar levels of accuracy. When a positive test was observed in one of a combination of shoulder tests used for diagnosing SLAP lesions or rotator cuff disease, sensitivity increased substantially whilst specificity decreased. CONCLUSIONS: The diagnostic accuracy of isolated standard shoulder tests in recreational athletes was over-all very poor, potentially due to the majority of athletes (71%) having concomitant shoulder injuries. Most likely, this means that many of these injuries are missed in general practice and treatment is therefore delayed. Clinical examination of the shoulder should involve a combination of clinical tests in order to identify likely intra articular pathology which may warrant referral to specialist for surgery.