Yung-Shen Tsai

The role of upper torso and pelvis rotation in driving performance during the golf swing

Abstract While the role of the upper torso and pelvis in driving performance is anecdotally appreciated by golf instructors, their actual biomechanical role is unclear. The aims of this study were to describe upper torso and pelvis rotation and velocity during the golf swing and determine their role in ball velocity. One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver. Upper torso and pelvic rotation and velocity, and torso-pelvic separation and velocity, were measured for each swing. Ball velocity was assessed with a golf launch monitor. Group differences (groups based on ball velocity) and moderate relationships (r ≥ 0.50; P < 0.001) were observed between an increase in ball velocity and the following variables: increased torso – pelvic separation at the top of the swing, maximum torso – pelvic separation, maximum upper torso rotation velocity, upper torso rotational velocity at lead arm parallel and last 40 ms before impact, maximum torso – pelvic separation velocity and torso – pelvic separation velocity at both lead arm parallel and at the last 40 ms before impact. Torso – pelvic separation contributes to greater upper torso rotation velocity and torso – pelvic separation velocity during the downswing, ultimately contributing to greater ball velocity. Golf instructors can consider increasing ball velocity by maximizing separation between the upper torso and pelvis at the top of and initiation of the downswing.

An eight-week golf-specific exercise program improves physical characteristics, swing mechanics, and golf performance in recreational golfers

The purpose of this study was to determine the effects of an 8-week golf-specific exercise program on physical characteristics, swing mechanics, and golf performance. Fifteen trained male golfers (47.2 ± 11.4 years, 178.8 ± 5.8 cm, 86.7 ± 9.0 kg, and 12.1 ± 6.4 U.S. Golf Association handicap) were recruited. Trained golfers was defined operationally as golfers who play a round of golf at least 2–3 times per week and practice at the driving range at least 2–3 times per week during the regular golf season. Subjects performed a golf-specific conditioning program 3–4 times per week for 8 weeks during the off-season in order to enhance physical characteristics. Pre- and posttraining testing of participants included assessments of strength (torso, shoulder, and hip), flexibility, balance, swing mechanics, and golf performance. Following training, torso rotational strength and hip abduction strength were improved significantly (p = 0.05). Torso, shoulder, and hip flexibility improved significantly in all flexibility measurements taken (p = 0.05). Balance was improved significantly in 3 of 12 measurements, with the remainder of the variables demonstrating a nonsignificant trend for improvement. The magnitude of upper-torso axial rotation was decreased at the acceleration (p = 0.015) and impact points (p = 0.043), and the magnitude of pelvis axial rotation was decreased at the top (p = 0.031) and acceleration points (p = 0.036). Upper-torso axial rotational velocity was increased significantly at the acceleration point of the golf swing (p = 0.009). Subjects increased average club velocity (p = 0.001), ball velocity (p = 0.001), carry distance (p = 0.001), and total distance (p = 0.001). These results indicate that a golf-specific exercise program improves strength, flexibility, and balance in golfers. These improvements result in increased upper-torso axial rotational velocity, which results in increased club head velocity, ball velocity, and driving distance.

The Effect of Direction and Reaction on the Neuromuscular and Biomechanical Characteristics of the Knee during Tasks that Simulate the Noncontact Anterior Cruciate Ligament Injury Mechanism

Background Jumping and landing tasks that have a change in direction have been implicated as a mechanism of noncontact anterior cruciate ligament injury. Yet, to date, neuromuscular and biomechanical research has focused primarily on straight landing tasks during planned jumps. Hypothesis Lateral and reactive jumps increase the neuromuscular and biomechanical demands placed on the anterior cruciate ligament, and women perform these tasks differently from men. Study Design Controlled laboratory study. Methods A total of 18 male and 17 female healthy high school basketball players underwent an analysis of the knee during planned and reactive 2-legged stop-jump tasks in 3 different directions that included novel methodology to incorporate a reactive component. Ground-reaction forces, joint kinematics, joint kinetics, and electromyographic activity were assessed during the tasks. Results Jump direction and task (planned or reactive) significantly affected joint angles, ground-reaction forces, knee joint moments, and proximal anterior tibia shear forces; female players demonstrated different kinematic, kinetic, and electromyographic characteristics during these tasks. Conclusion and Clinical Relevance Jump direction significantly influenced knee biomechanics, suggesting that lateral jumps are the most dangerous of the stop-jumps. Reactive jumps were also significantly different, suggesting differences between planned laboratory experiments and actual athletic competition. The results of this study indicate that directional and reactive jumps should be included in research methodology and injury-prevention programs.

Strength, Flexibility, and Balance Characteristics of Highly Proficient Golfers

Despite the emergence of golf-specific training programs and training aids, relatively little research has been conducted examining the physical characteristics that are important to golf performance. We studied the strength, flexibility, and balance characteristics of golfers across 3 proficiency levels based on handicap index (HCP) (≤0, 1–9, and 10–20) to determine the physical characteristics unique to highly proficient golfers. A total of 257 (age: 45.5 ± 12.8 years, height: 180.6 ± 6.5 cm, weight: 87.9 ± 12.6 kg) healthy, male golfers participated in the study. Testing included an assessment of strength (torso, shoulder, and hip), flexibility (torso, shoulder, and hip), and single-leg balance. Golfers in the highest proficiency group (HCP = 0) had significantly (p ≤ 0.05) greater hip strength, torso strength, shoulder strength, shoulder flexibility, hip flexibility, torso flexibility, and balance (eyes open) than golfers in the lowest proficiency group (HCP 10–20). The results of this study demonstrate that better golfers possess unique physical characteristics that are important to greater proficiency. These characteristics have also been demonstrated to be modifiable through golf-specific training programs.

A Comparison of Physical Characteristics and Swing Mechanics Between Golfers With and Without a History of Low Back Pain

STUDY DESIGN Controlled laboratory study using a cross-sectional design. OBJECTIVES To examine the kinematics and kinetics of the trunk and the physical characteristics of trunk and hip in golfers with and without a history of low back pain (LBP). BACKGROUND Modified swing patterns and general exercises have been suggested for golfers with back pain. Yet we do not know what contributes to LBP in golfers. To create and validate a low back-specific exercise program to help prevent and improve back injuries in golfers, it may be valuable to understand the differences in biomechanical and physical characteristics of golfers with and without a history of LBP. METHODS Sixteen male golfers with a history of LBP were matched by age and handicap with 16 male golfers without a history of LBP. All golfers underwent a biomechanical swing analysis, trunk and hip strength and flexibility assessment, spinal proprioception testing, and postural stability testing. RESULTS The group with a history of LBP demonstrated significantly less trunk extension strength at 60 degrees/s and left hip adduction strength, as well as limited trunk rotation angle toward the nonlead side. No significant differences were found in postural stability, trunk kinematics, and maximum spinal moments during the golf swing. CONCLUSION Deficits observed in this study may affect a golfers ability to overcome the spinal loads generated during the golf swing over time. Exercises for improving these physical deficits can be considered, although the cause-effect of LBP in golfers still cannot be determined.

Topical cooling (icing) delays recovery from eccentric exercise-induced muscle damage.

Abstract Tseng, C-Y, Lee, J-P, Tsai, Y-S, Lee, S-D, Kao, C-L, Liu, T-C, Lai, C-S, Harris, MB, and Kuo, C-H. Topical Cooling (Icing) Delays Recovery From Eccentric Exercise–Induced Muscle Damage. J Strength Cond Res 27(5): 1354–1361, 2013—It is generally thought that topical cooling can interfere with blood perfusion and may have positive effects on recovery from a traumatic challenge. This study examined the influence of topical cooling on muscle damage markers and hemodynamic changes during recovery from eccentric exercise. Eleven male subjects (age 20.2 ± 0.3 years) performed 6 sets of elbow extension at 85% maximum voluntary load and randomly assigned to topical cooling or sham groups during recovery in a randomized crossover fashion. Cold packs were applied to exercised muscle for 15 minutes at 0, 3, 24, 48, and 72 hours after exercise. The exercise significantly elevated circulating creatine kinase-MB isoform (CK-MB) and myoglobin levels. Unexpectedly, greater elevations in circulating CK-MB and myoglobin above the control level were noted in the cooling trial during 48–72 hours of the post-exercise recovery period. Subjective fatigue feeling was greater at 72 hours after topical cooling compared with controls. Removal of the cold pack also led to a protracted rebound in muscle hemoglobin concentration compared with controls. Measures of interleukin (IL)-8, IL-10, IL-1&bgr;, and muscle strength during recovery were not influenced by cooling. A peak shift in IL-12p70 was noted during recovery with topical cooling. These data suggest that topical cooling, a commonly used clinical intervention, seems to not improve but rather delay recovery from eccentric exercise–induced muscle damage.

Comprehensive classification test of scapular dyskinesis: A reliability study

BACKGROUND Assessment of scapular dyskinesis (SD) is of clinical interest, as SD is believed to be related to shoulder pathology. However, no clinical assessment with sufficient reliability to identify SD and provide treatment strategies is available. OBJECTIVES The purpose of this study was to investigate the reliability of the comprehensive SD classification method. DESIGN Cross-sectional reliability study. METHOD Sixty subjects with unilateral shoulder pain were evaluated by two independent physiotherapists with a visual-based palpation method. SD was classified as single abnormal scapular pattern [inferior angle (pattern I), medial border (pattern II), superior border of scapula prominence or abnormal scapulohumeral rhythm (pattern III)], a mixture of the above abnormal scapular patterns, or normal pattern (pattern IV). The assessment of SD was evaluated as subjects performed bilateral arm raising/lowering movements with a weighted load in the scapular plane. Percentage of agreement and kappa coefficients were calculated to determine reliability. RESULTS Agreement between the 2 independent physiotherapists was 83% (50/60, 6 subjects as pattern III and 44 subjects as pattern IV) in the raising phase and 68% (41/60, 5 subjects as pattern I, 12 subjects as pattern II, 12 subjects as pattern IV, 12 subjects as mixed patterns I and II) in the lowering phase. The kappa coefficients were 0.49-0.64. CONCLUSIONS We concluded that the visual-based palpation classification method for SD had moderate to substantial inter-rater reliability. The appearance of different types of SD was more pronounced in the lowering phase than in the raising phase of arm movements.

Deep ocean mineral water accelerates recovery from physical fatigue

BackgroundDeep oceans have been suggested as a possible site where the origin of life occurred. Along with this theoretical lineage, experiments using components from deep ocean water to recreate life is underway. Here, we propose that if terrestrial organisms indeed evolved from deep oceans, supply of deep ocean mineral water (DOM) to humans, as a land creature, may replenish loss of molecular complexity associated with evolutionary sea-to-land migration.MethodsWe conducted a randomized, double-blind, placebo-controlled crossover human study to evaluate the effect of DOM, taken from a depth of 662 meters off the coast of Hualien, Taiwan, on time of recovery from a fatiguing exercise conducted at 30°C.ResultsThe fatiguing exercise protocol caused a protracted reduction in aerobic power (reduced VO2max) for 48 h. However, DOM supplementation resulted in complete recovery of aerobic power within 4 h (P < 0.05). Muscle power was also elevated above placebo levels within 24 h of recovery (P < 0.05). Increased circulating creatine kinase (CK) and myoglobin, indicatives of exercise-induced muscle damage, were completely eliminated by DOM (P < 0.05) in parallel with attenuated oxidative damage (P < 0.05).ConclusionOur results provide compelling evidence that DOM contains soluble elements, which can increase human recovery following an exhaustive physical challenge.

Effects of an eight-week whole body vibration on lower extremity muscle tone and function in children with cerebral palsy

The aim of this study was to evaluate the effect of an eight-week whole body vibration (WBV) on lower extremity spasticity and ambulatory function in children with cerebral palsy with a complete crossover design. Sixteen participants aged 9.2 (2.1) years participated in this study. Half of the participants received a 10-min WBV, 3 times a week for 8 weeks. Then a 4-week washout period followed, after which they received a sham WBV 3 times a week for 8 weeks. The other half received the intervention in a reversed order. The participants were evaluated via variables measuring range-of-motion, muscle tone, and ambulatory function before, immediately after, 1 day after, and 3 days after each intervention. Repeated-measures analyses revealed significant beneficial effects on most variables expect the passive range-of-motion measurement. Significant correlations were found between timed up-and-go and relaxation index, and between timed up-and-go and six-minute walk test. The results suggested that an 8-week WBV intervention normalized muscle tone, improved active joint range and enhanced ambulatory performance in children with cerebral palsy for at least 3 days. These indicated that regular WBV can serve as an alternative, safe, and efficient treatment for these children in both clinical and home settings.

Motion analysis of throwing Boccia balls in children with cerebral palsy.

Boccia is a sport suitable for children with cerebral palsy (CP). Throwing Boccia balls requires upper extremity and torso coordination. This study investigated the differences between children with CP and normally developed children regarding throwing patterns of Boccia balls. Thirteen children with bilateral spastic CP and 20 normally developed children participated in this study. The tests in this study were a pediatric reach test and throwing of Boccia balls. A 3D electromagnetic motion tracking system and a force plate were synchronized to record and analyze biomechanical parameters of throwing Boccia balls. The results of the pediatric reach test for participants with CP were significantly worse than those for normally developed participants. The 2 groups of participants did not significantly differ regarding the distance between a thrown Boccia ball and a target ball (jack). Participants with CP demonstrated significantly longer movement duration, smaller amplitude of elbow movement, greater amplitudes of shoulder abduction and flexion, slower maximal velocity of torso flexion and the linear velocity of moving the wrist joint forward, faster maximal velocity of head flexion, and smaller sway ratio compared with normally developed participants when throwing Boccia balls. Participants with CP seemed to mainly use head and shoulder movements to bring the Boccia balls forward with limited torso movement. Normally developed participants brought the Boccia ball forward with faster torso and greater elbow movement while stabilizing head and shoulder movements. Nevertheless, participants with CP did not demonstrate significantly worse performance in the throwing accuracy of Boccia balls.