Swing kinematics for male and female pro golfers.

The purpose of the study was to compare golf swing kinematics between female and male professional golfers, with particular focus on areas where different risks of injury exist and variables that may be related to driving distance. Twenty-five LPGA golfers and twenty-five PGA golfers were tested. Customized computer software was developed to analyze kinematic data obtained with an optoelectronic system at 240 Hz.

Electromyographic analysis of the supraspinatus and deltoid muscles during 3 common rehabilitation exercises.

Context: Investigators have observed electromyographic (EMG) activity of the supraspinatus muscle and reported conflicting results.

Objective: To quantify EMG activity of the supraspinatus, middle deltoid, and posterior deltoid muscles during exercises commonly used in rehabilitation.

Design: One-factor, repeated-measures design.

Kinematic analysis of swing in pro and amateur golfers.

As golf grows in popularity, golf related injuries have increased. The purpose of this study was to calculate and compare upper body kinematics of healthy male golfers from different skill levels. Kinematic data were obtained from 18 professional, 18 low handicap, 18 mid handicap and 18 high handicap golfers with an optoelectronic system at 240 frames per second.

Pitching biomechanics as a pitcher approaches muscular fatigue during a simulated baseball game.

Background: The effects of approaching muscular fatigue on pitching biomechanics are currently unknown. As a pitcher fatigues, pitching mechanics may change, leading to a decrease in performance and an increased risk of injury.

Hypothesis: As a pitcher approaches muscular fatigue, select pitching biomechanical variables will be significantly different than they were before muscular fatigue.

Electromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises.

Study Design: Prospective single-group repeated-measures design.

Objectives: To quantify electromyographic (EMG) muscle activity of the infraspinatus, teres minor, supraspinatus, posterior deltoid, and middle deltoid during exercises commonly used to strengthen the shoulder external rotators.

Background: Exercises to strengthen the external rotators are commonly prescribed in rehabilitation, but the amount of EMG activity of the infraspinatus, teres minor, supraspinatus, and deltoid during these exercises has not been thoroughly studied to determine which exercises would be most effective to achieve strength gains.

Kinematic and kinetic comparisons between American and Korean professional baseball pitchers.

The purpose of this study was to quantify and compare kinematic, temporal, and kinetic characteristics of American and Korean professional pitchers in order to investigate differences in pitching mechanics, performance, and injury risks among two different cultures and populations of baseball pitchers. Eleven American and eight Korean healthy professional baseball pitchers threw multiple fastball pitches off an indoor throwing mound positioned at regulation distance from home plate. A Motion Analysis three-dimensional automatic digitizing system was used to collect 200 Hz video data from four electronically synchronized cameras.

Effects of technique variations on knee biomechanics during the squat and leg press.

Purpose: The specific aim of this project was to quantify knee forces and muscle activity while performing squat and leg press exercises with technique variations.

Methods: Ten experienced male lifters performed the squat, a high foot placement leg press (LPH), and a low foot placement leg press (LPL) employing a wide stance (WS), narrow stance (NS), and two foot angle positions (feet straight and feet turned out 30 degrees ).

Results: No differences were found in muscle activity or knee forces between foot angle variations.

Kinematic comparisons of 1996 Olympic baseball pitchers.

The aim of this study was to compare and evaluate the kinematics of baseball pitchers who participated in the 1996 XXVI Centennial Olympic Games. Two synchronized video cameras operating at 120 Hz were used to video 48 pitchers from Australia, Japan, the Netherlands, Cuba, Italy, Korea, Nicaragua and the USA. All pitchers were analysed while throwing the fastball pitch.

A three-dimensional biomechanical analysis of the squat during varying stance widths.

Purpose: The purpose of this study was to quantify biomechanical parameters employing two-dimensional (2-D) and three-dimensional (3-D) analyses while performing the squat with varying stance widths.

Methods: Two 60-Hz cameras recorded 39 lifters during a national powerlifting championship. Stance width was normalized by shoulder width (SW), and three stance groups were defined: 1) narrow stance squat (NS), 107 +/- 10% SW; 2) medium stance squat (MS), 142 +/- 12% SW; and 3) wide stance squat (WS), 169 +/- 12% SW.

A three-dimensional biomechanical analysis of sumo and conventional style deadlifts.

Purpose: Strength athletes often employ the deadlift in their training or rehabilitation regimens. The purpose of this study was to quantify kinematic and kinetic parameters by employing a three-dimensional analysis during sumo and conventional style deadlifts.

Methods: Two 60-Hz video cameras recorded 12 sumo and 12 conventional style lifters during a national powerlifting championship.

Biomechanics and motion analysis applied to sports.

The development of motion analysis and the application of biomechanical analysis techniques to sports has paralleled the exponential growth of computational and videographic technology. Technological developments have provided for advances in the investigation of the human body and the action of the human body during sports believed to be unobtainable a few years ago. Technological advancements have brought biomechanical applications into a wide range of fields from orthopedics to entertainment.

Effects of throwing overweight and underweight baseballs on throwing velocity and accuracy.

The purpose of this review is to determine how throwing overweight and underweight baseballs affects baseball throwing velocity and accuracy. Two studies examined how a warm-up with overweight baseballs affected throwing velocity and accuracy of 5 oz regulation baseballs. One of these studies showed significant increases in throwing velocity and accuracy, while the other study found no significant differences.

Kinematic and kinetic comparison of baseball pitching among various levels of development.

Proper biomechanics help baseball pitchers minimize their risk of injury and maximize performance. However previous studies involved adult pitchers only. In this study, 23 youth, 33 high school, 115 college, and 60 professional baseball pitchers were analyzed.

An analytical model of the knee for estimation of internal forces during exercise.

An analytical model of the knee joint was developed to estimate the forces at the knee during exercise. Muscle forces were estimated based upon electromyographic activities during exercise and during maximum voluntary isometric contraction (MVIC), physiological cross-sectional area (PCSA), muscle fiber length at contraction and the maximum force produced by an unit PCSA under MVIC. Tibiofemoral compressive force and cruciate ligaments' tension were determined by using resultant force and torque at the knee, muscle forces, and orientations and moment arms of the muscles and ligaments.

Biomechanics of windmill softball pitching with implications about injury mechanisms at the shoulder and elbow.

Underhand pitching has received minimal attention in the sports medicine literature. This may be due to the perception that, compared with overhead pitching, the underhand motion creates less stress on the arm, which results in fewer injuries. The purpose of this study was to calculate kinematic and kinetic parameters for the pitching motion used in fast pitch softball.

Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises.

Purpose: Although closed (CKCE) and open (OKCE) kinetic chain exercises are used in athletic training and clinical environments, few studies have compared knee joint biomechanics while these exercises are performed dynamically. The purpose of this study was to quantify knee forces and muscle activity in CKCE (squat and leg press) and OKCE (knee extension).

Methods: Ten male subjects performed three repetitions of each exercise at their 12-repetition maximum.

A comparison of tibiofemoral joint forces and electromyographic activity during open and closed kinetic chain exercises.

We chose to investigate tibiofemoral joint kinetics (compressive force, anteroposterior shear force, and extension torque) and electromyographic activity of the quadriceps, hamstring, and gastrocnemius muscles during open kinetic chain knee extension and closed kinetic chain leg press and squat. Ten uninjured male subjects performed 4 isotonic repetitions with a 12 repetition maximal weight for each exercise. Tibiofemoral forces were calculated using electromyographic, kinematic, and kinetic data.

Biomechanics of overhand throwing with implications for injuries.

Proper throwing mechanics may enable an athlete to achieve maximum performance with minimum chance of injury. While quantifiable differences do exist in proper mechanics for various sports, certain similarities are found in all overhand throws. One essential property is the utilisation of a kinetic chain to generate and transfer energy from the larger body parts to the smaller, more injury-prone upper extremity.