Four week lumbopelvic-hip complex intervention program and its effects on tuck jump assessment in active youth

Injury in youth physical activity has become a major concern with the rising rate of participation. Lumbopelvic-hip complex (LPHC) stability, also known as core stability, has been found to contribute to proper force dissipation and ultimately more effective mechanics. Therefore, the purpose of this study was to examine the effects of a LPHC neuromuscular strengthening program on at-risk youth using the Tuck Jump Assessment. Forty-five youth grades 6, 7, and 8 participated in the Tuck Jump Assessment. Then those participants who scores were indicative of \u27at risk\u27 were enrolled in a four-week LPHC intervention program. Those participants whose sores did not fall into the \u27at risk\u27 category were the control group. After four-weeks groups were retested with the Tuck Jump Assessment. A paired-T test revealed that the intervention group had significant improvement on their Tuck Jump Assessment (p \u3c 0.01), while the control group\u27s scores did not change. It was thus concluded that strengthening the LPHC provides more control and stability in functional activity. Implementation of an intervention program in youth may decrease the susceptibility to injury in physical activity as well as contribute to more sound mechanics

RELATIONSHIP BETWEEN HIP RANGE OF MOTION AND PITCHING KINEMATICS IN HIGH SCHOOL BASEBALL PITCHERS

The purpose of this study was to examine the association of hip rotational range of motion (ROM) with lower extremity and trunk kinematics in high school baseball pitchers. Twenty-five healthy high school baseball pitchers volunteered (15.9 ± 1.1 years). Passive hip internal rotation (IR) and external rotation (ER) ROM was measured with the pitchers seated using a digital inclinometer. Total hip ROM (IR + ER) was calculated for the stride leg and drive leg. Biomechanical data were collected with a 3-D electromagnetic tracking system while pitchers threw three fastballs. Simple linear regression analysis determined drive and stride leg hip IR, ER, and total ROM did not predict pitching kinematics. Future research should continue identifying parameters associated with altered biomechanics that may place baseball pitchers at increased risk of injury

THE RELATIONSHIP BETWEEN STRIDE MECHANICS AND SHOULDER DISTRACTION FORCE IN COLLEGIATE SOFTBALL PITCHERS

The purpose of this study was to determine the relationship between stride mechanics and shoulder distraction force in softball pitchers. Sixty-three collegiate softball pitchers (age: 20.1 ± 1.3 yrs, height: 173.3 ± 7.4 cm, weight: 79.7 ± 11.7 kg) participated and threw three maximal effort fastballs for a strike. Kinematic data were collected using an electromagnetic tracking system with a sampling frequency of 100 Hz. Regression analysis revealed a significant positive relationship between stride length and shoulder distraction force [R2 = .11; F (1, 61) = 7.345, p = .009], where stride length accounted for 11% of the variation in shoulder distraction force. Specifically, shoulder distraction force increased by .94 N/kg for every 10% increase in stride length normalized as a percentage of body height

RELIABILTY OF ELECTROMAGNETIC TRACKING IN DESCRIBING PITCHING MECHANICS

The purpose of this study was to establish the reliability of an electromagnetic tracking device (ETD) in analyzing young baseball pitchers. Two data collection sessions in which throwing kinematics were recorded were conducted across a five day span. Joint kinematics were calculated using the International Shoulder Group recommendations. Correlation analyses examining inter-day reliability of the ETD showed that the system was within acceptable limits (r > 0.73). Throughout the selected instances of the pitch cycle, the ETD used in the current study was shown to be reliable across multiple data collection session with ICCs ranging from r = 0.73 to 0.86. It appears so long as the setup, sensor attachment, and digitization protocols remain consistent across data collection sessions, ETD’s are a reliable tool in analyzing throwing movements in younger subjects

TRUNK AND UPPER EXTREMITY KINEMATICS OF THE OFFSIDE FOREHAND POLO SWING IN PROFESSIONAL POLO ATHLETES

The purpose of this study was to examine trunk (flexion, lateral flexion, rotation) and upper extremity (shoulder horizontal abduction, elevation, and elbow flexion) kinematics of the offside forehand polo swing between professional male and female polo athletes. Kinematic data were collected while participants performed the offside forehand polo swing on a stationary wooden horse. The polo swing was analyzed at three events: take away (TA), top of back swing (TOB) and ball contact (BC). Results revealed significant differences in trunk and upper extremity kinematics between the male and female professional polo athlete. Further investigation into these mechanical differences, along with the influence of live play and performance variables are necessitated to understand mechanics for the most powerful swin

EFFICIENCY INDEX USED TO ASSESS SHOULDER STRESS IN COLLEGE SOFTBALL PITCHERS THROUGHOUT A SIMULATED GAME

Shoulder distraction forces in softball pitching are known to have a positive impact on performance yet a negative impact on musculoskeletal health. The purpose of this study was to assess changes in shoulder stress across innings pitched using Efficiency Arm-Stress Index (EASI) scores. Motion capture was used on collegiate softball pitchers pitching a simulated game. Peak shoulder distraction force was obtained using inverse dynamics procedures and used to calculate an EASI score (fastball velocity divided by peak shoulder distraction force in percent body weight). A RM·ANOVA revealed inning had no effect on EASI score (F[6,7]=1.28, p=0.286). Understanding a pitcher’s efficiency score may help shape individual pitching loads. Future work should investigate clinically meaningful changes in efficiency scores and mechanisms behind low efficiencies

PITCHING MECHANICS AND PAIN HISTORY IN COLLEGIATE SOFTBALL PITCHERS

The purpose of this study was to compare collegiate softball pitchers’ mechanics with and without upper extremity pain. Fifty-five collegiate softball pitchers volunteered to participate. Based on a pain history questionnaire, participants were divided into two groups: upper extremity pain, and pain free. Kinematic data were collected on the change-up softball pitch using an electromagnetic tracking system. The group exhibiting upper extremity pain illustrated greater shoulder horizontal abduction at foot contact, and less trunk lateral flexion towards the throwing side at ball release compared to the pain free group. In combination, the authors speculate these injury-prone positions and forces about the shoulder could be the result of improper energy transfer along the kinetic chain

Drive Leg Ground Reaction Forces and Rate of Force Development Over Consecutive Windmill Softball Pitches

BACKGROUND: Windmill softball pitching is a highly skilled movement, combining whole body coordination with explosive force. Successful pitching requires sequential movement to transfer energy produced by the lower extremity to the pitching arm. Therefore, drive leg ground reaction force (GRF) and the time over which a pitcher can develop force during push off, defined as rate of force development (RFD), is essential for optimal performance. The aim of this study was to examine GRF and RFD in the drive leg during the windmill softball pitch, as well as pitch velocity, throughout a simulated game. METHODS: Fourteen softball pitchers (17.9±2.3 years, 166.4±8.7cm, 72.2±12.6kg) pitched a simulated game. Pitch velocity and anterior-posterior and vertical GRF and RFD, each normalized to body weight, were collected for each inning. Average pitch speed remained consistent across all seven innings, 49.57±0.42mph. Changes in GRF and RFD were assessed, with level of significance set as P\u3c0.05. RESULTS: A one-way repeated measures analysis of variance showed no significant differences in apGRF%BW (P=0.297), vGRF%BW (P=0.574), apRFD (BW/s) (P=0.085) and vRFD (BW/s) (P=0.059). CONCLUSIONS: Training programs can be improved with the knowledge of the magnitude and rate in which forces are developed by the drive leg during push-off of the windmill softball pitch