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1.
Abstract

Although the golf coaching literature stresses the importance of weight transfer during the swing, research has been conflicting or lacking statistical support. A potential problem with previous studies is that no attempt was made to account for different movement strategies in the golf swing. This study evaluated the relationship between centre of pressure measures and club head velocity within two previously identified swing styles, the “Front Foot” and “Reverse” styles. Thirty-nine Front Foot golfers and 19 Reverse golfers performed swings with a driver while standing on two force plates. From the force plate data, centre of pressure displacement, velocity, range, and timing parameters were calculated. Correlation and regression analysis indicated that a larger range of centre of pressure and a more rapid centre of pressure movement in the downswing was associated with a larger club head velocity at ball contact for the Front Foot group. For the Reverse golfers, positioning the centre of pressure further from the back foot at late backswing and a more rapid centre of pressure transfer towards the back foot at ball contact was associated with a larger club head velocity at ball contact. This study has highlighted the importance of identifying different movement strategies before evaluating performance measures, as different parameters were found to be important for the Front Foot and Reverse styles.  相似文献   

2.
Although the golf coaching literature stresses the importance of weight transfer during the swing, research has been conflicting or lacking statistical support. A potential problem with previous studies is that no attempt was made to account for different movement strategies in the golf swing. This study evaluated the relationship between centre of pressure measures and club head velocity within two previously identified swing styles, the "Front Foot" and "Reverse" styles. Thirty-nine Front Foot golfers and 19 Reverse golfers performed swings with a driver while standing on two force plates. From the force plate data, centre of pressure displacement, velocity, range, and timing parameters were calculated. Correlation and regression analysis indicated that a larger range of centre of pressure and a more rapid centre of pressure movement in the downswing was associated with a larger club head velocity at ball contact for the Front Foot group. For the Reverse golfers, positioning the centre of pressure further from the back foot at late backswing and a more rapid centre of pressure transfer towards the back foot at ball contact was associated with a larger club head velocity at ball contact. This study has highlighted the importance of identifying different movement strategies before evaluating performance measures, as different parameters were found to be important for the Front Foot and Reverse styles.  相似文献   

3.
Abstract

When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the “front foot” style or the “reverse” style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.  相似文献   

4.
ABSTRACT

The purpose of this study was to investigate the influence of sex and planning time on spatial and temporal aspects of the whole-body centre of mass (CoM) mechanics during sidestepping performance. Seventeen female and 17 male collegiate team sport athletes completed seven anticipated and seven unanticipated sidestep trials during which three-dimensional CoM data were recorded. Female athletes had a reduced ability to reorient their CoM towards the desired direction of travel (lower medio-lateral and anterior-posterior CoM velocity) than their male counterparts, with reduced medial (closer to stance foot) and increased posterior positioning of CoM relative to the stance foot (p < 0.05). When planning time was limited, female and male athletes performed sidestepping with CoM further from the stance foot (more medial) and more anterior than in the anticipated condition (p < 0.05) at reduced medio-lateral velocities. Sex and condition control strategy differences were evident both in the preparatory phase and the stance phase. The current research draws attention to the foreseen benefits of training athletes, with particular emphasis on females, to direct CoM towards the desired direction of travel in the preparatory and stance phases within temporally constrained situations for improved performance.  相似文献   

5.
When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the "front foot" style or the "reverse" style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.  相似文献   

6.
Weight transfer research in the golf swing has produced conflicting and inconclusive results. A limitation of previous studies is the assumption that only one swing "style" exists within the golf swing. If different styles, or movement strategies, exist and if the different styles are analysed together in a single group, statistical errors will result. The aim of this study was to determine if different weight transfer styles exist in the golf swing by applying cluster analysis to centre of pressure (CP) patterns in the direction of hit (CPy) and to evaluate cluster analysis issues. Sixty-two professional to high handicap golfers performed simulated drives, hitting a golf ball into a net, while standing on two force plates. Centre of pressure position relative to the feet (CPy%) was quantified at eight swing events identified from 200-Hz video. Cluster analysis identified two major CPy% styles: a "Front Foot" style and a "Reverse" style. Both styles began with CPy% positioned evenly between the feet, moved to the back foot during backswing, and then forward during early downswing. Beyond early downswing, the Front Foot group continued to move CPy% to the Front Foot through to ball contact, while the Reverse group moved CPy% towards the back foot through ball contact and follow-through. Both weight transfer styles were evident across skill levels from professional to high handicap golfers, indicating that neither style was a technical error. Cluster analysis should include hierarchical and non-hierarchical clustering and use objective measures combined with theoretical assessment to determine the optimal number of clusters. Furthermore, a number of validation procedures should always be used to validate the solution.  相似文献   

7.
Disagreements exist in the literature regarding the manner in which weight should be dynamically shared during the golf swing, both within-feet and between the back- and target-foot, to generate maximal clubhead speed. The purpose of this study was to determine whether preferential foot-loading locations underlie weight sharing by examining the correlation between clubhead speed and maximum plantar pressure (PP) distributions. Thirty-two amateur golfers with handicap indexes ranging from 2.7 to 25 performed 10 driver swings on artificial turf following a warm-up. PP distributions were recorded at 100 Hz, and clubhead speed was recorded using a ball-tracking Doppler radar system. Maximum PPs were extracted from a 2-s window approximately centred on ball contact and were regressed against clubhead speed. Significance was assessed over the entire foot surface using statistical parametric mapping (SPM), a spatially continuous technique. SPM revealed, at relatively high anatomical resolution, significant positive correlations between clubhead speed and PPs in the lateral target-foot (P < 0.05). This suggests that not only weight transfer but also weight-transfer location may be an important determinant of clubhead speed in amateur golfers.  相似文献   

8.
Abstract

We previously estimated the timing when ball game defenders detect relevant information through visual input for reacting to an attacker's running direction after a cutting manoeuvre, called cue timing. The purpose of this study was to investigate what specific information is relevant for defenders, and how defenders process this information to decide on their opponents' running direction. In this study, we hypothesised that defenders extract information regarding the position and velocity of the attackers' centre of mass (CoM) and the contact foot. We used a model which simulates the future trajectory of the opponent's CoM based upon an inverted pendulum movement. The hypothesis was tested by comparing observed defender's cue timing, model-estimated cue timing using the inverted pendulum model (IPM cue timing) and cue timing using only the current CoM position (CoM cue timing). The IPM cue timing was defined as the time when the simulated pendulum falls leftward or rightward given the initial values for position and velocity of the CoM and the contact foot at the time. The model-estimated IPM cue timing and the empirically observed defender's cue timing were comparable in median value and were significantly correlated, whereas the CoM cue timing was significantly more delayed than the IPM and the defender's cue timings. Based on these results, we discuss the possibility that defenders may be able to anticipate the future direction of an attacker by forwardly simulating inverted pendulum movement.  相似文献   

9.
Weight transfer has been identified as important in group-based analyses. The aim of this study was to extend this work by examining the importance of weight transfer in the golf swing on an individual basis. Five professional and amateur golfers performed 50 swings with the driver, hitting a ball into a net. The golfer's centre of pressure position and velocity, parallel with the line of shot, were measured by two force plates at eight swing events that were identified from high-speed video. The relationships between these parameters and club head velocity at ball contact were examined using regression statistics. The results did support the use of group-based analysis, with all golfers returning significant relationships. However, results were also individual-specific, with golfers returning different combinations of significant factors. Furthermore, factors not identified in group-based analysis were significant on an individual basis. The most consistent relationship was a larger weight transfer range associated with a larger club head velocity (p < 0.05). All golfers also returned at least one significant relationship with rate of weight transfer at swing events (p < 0.01). Individual-based analysis should form part of performance-based biomechanical analysis of sporting skills.  相似文献   

10.
Lumbar spinal loads and muscle activity during a golf swing   总被引：1，自引：0，他引：1  
This study estimated the lumbar spinal loads at the L4-L5 level and evaluated electromyographic (EMG) activity of right and left rectus abdominis, external and internal obliques, erector spinae, and latissimus dorsi muscles during a golf swing. Four super VHS camcorders and two force plates were used to obtain three-dimensional (3D) kinematics and kinetics of golf swings performed by five male collegiate golfers. Average EMG levels for different phases of golf swing were determined. An EMG-assisted optimization model was applied to compute the contact forces acting on the L4-L5. The results revealed a mean peak compressive load of over six times the body weight (BW) during the downswing and mean peak anterior and medial shear loads approaching 1.6 and 0.6 BW during the follow-through phases. The peak compressive load estimated in this study was high, but less than the corresponding value (over 8 BW) reported by a previous study. Average EMG levels of different muscles were the highest in the acceleration and follow-through phases, suggesting a likely link between co-contractions of paraspinal muscles and lumbar spinal loads.  相似文献   

11.
Abstract

During practice and competition, golfers are required to use submaximal effort to hit the ball a given distance, i.e., perform a partial shot. While the full golf swing has undergone extensive research, little has addressed partial shots and the biomechanical modifications golfers employ. This study investigates the biomechanical changes between full and partial swings, and determines if the partial swing is a scaled version of the full swing. Using a repeated measures design, 13 male golfers completed a minimum of 10 swings in the full and partial swing conditions, whilst club, ball, kinematic, and kinetic parameters were recorded. Large and statistically significant reductions in body motion (centre of pressure ellipse: 33.0%, p = 0.004, d = 2.26), combined with moderate reductions in lateral shift (25.5%, p = 0.004, d = 0.33) and smaller reductions in trunk rotation (arm to vertical at top of backswing: 14.1%, p = 0.002, d = 2.58) indicate golfers favour larger reductions in proximal measures, combined with diminished reductions as variables moved distally. Furthermore, the partial swing was not found to be a scaled version of the full swing implying a new approach to coaching practices might be considered.  相似文献   

12.
Coaches have identified the batter's weight shift as a critical component for promoting proper timing and balance in a baseball swing. Analysing the weight shift through maximum horizontal (Fx) and vertical (Fz) ground reaction forces (GRFs) of professional batters (N = 29; height = 185 +/- 6 cm; mass = 92 +/- 9 kg), the purpose of this study was to compare GRFs among swings against fastballs and changeups. General linear models were used to compare three conditions of interest: successful results against fastballs, successful results against changeups, and unsuccessful results against changeups. Batters had a similar loading mechanism and initial weight transfer from back foot to front foot regardless of pitch type, but peak front foot GRFx and GRFz occurred with significantly different magnitudes and at significantly different times, depending on the pitch type and hit result. Peak front foot GRFs were greater for successful swings against fastballs compared to both successful and unsuccessful swings against changeups. Peak front foot GRFs of unsuccessful swings against changeups occurred, on average, 15-20 ms earlier than successful swings against changeups and 30-35 ms earlier than successful swings against fastballs, quantifying how a changeup can disrupt the coordination of a hitter's weight shift.  相似文献   

13.
ABSTRACT

The purpose of this study was to investigate the effects of slope on three-dimensional running kinematics at high speed. Thirteen male sprinters ran at high speed (7.5 m/s) on a motorised treadmill in each a level and a 5.0% slope condition. Three-dimensional motion analysis was conducted to compare centre of mass (CoM) energetics, pelvis segment and lower limb joints kinematics. We found that contact time was not affected by the slope, whereas flight time and step length were significantly shorter in uphill compared to level running. Uphill running reduced negative CoM work and increased positive CoM work compared to level running. Ankle, knee and hip joints were more flexed at initial ground contact, but only the knee was more extended at the end of stance in uphill compared to level running. Additionally, the hip joint was more abducted, and the free leg side of the pelvis was more elevated at the end of stance in uphill running. Our results demonstrate that joint motion must be developed from a more flexed/adducted position at initial contact through a greater range of motion compared to level running in order to meet the greater positive CoM work requirements in uphill running at high speed.  相似文献   

14.
Abstract

Twenty right-handed male golfers participated as subjects in an investigation of the two-dimensional weight transfer pattern produced during the golf swing. Ten subjects possessed handicaps of less than 10 strokes while the remaining 10 subjects had handicaps greater than 20. Center of vertical force locations were sampled during the swing with a computerized forceplate at a rate of 350 Hz. The occurrence of the initiation of the downswing (TOS) was monitored by a vacuum transducer in the club grip while ball contact (CON) was monitored by a laser/photocell system. Variables analyzed consisted of minimum/maximum force distribution ratios from heel to toe and from back foot to target foot as well as distribution ratios at TOS and CON. Intraclass correlation coefficients showed all variables to be reliable for both groups (r > 0.8). A subsequent discriminant function analysis produced one significant function (p < .05) which served to distinguish between the low and high handicap groups. The accuracy of group membership predicted from weight transfer patterns was 85%.  相似文献   

15.
Abstract

Plantar pressure characteristics during fencing movements may provide more specific information about the influence of foot loading on overload injury patterns. Twenty-nine experienced fencers participated in the study. Three fencing-specific movements (lunge, advance, retreat) and normal running were performed with three different shoe models: Ballestra (Nike, USA), Adistar Fencing Lo (Adidas, Germany), and the fencers' own shoes. The Pedar system (Novel, Munich, Germany) was used to collect plantar pressures at 50 Hz. Peak pressures, force–time integrals and contact times for five foot regions were compared between four athletic tasks in the lunge leg and supporting leg. Plantar pressure analysis revealed characteristic pressure distribution patterns for the fencing movements. For the lunge leg, during the lunge and advance movements the heel is predominantly loaded; during retreat, it is the hallux. For the supporting leg, during the lunge and advance movements the forefoot is predominantly loaded; during retreat, it is the hallux. Fencing-specific movements load the plantar surface in a distinct way compared with running. An effective cushioning in the heel and hallux region would help to minimize foot loading during fencing-specific movements.  相似文献   

16.
For a valid determination of a rower’s mechanical power output, the anterior–posterior (AP) acceleration of a rower’s centre of mass (CoM) is required. The current study was designed to evaluate the accuracy of the determination of this acceleration using a full-body inertial measurement units (IMUs) suit in combination with a mass distribution model. Three methods were evaluated. In the first two methods, IMU data were combined with either a subject-specific mass distribution or a standard mass distribution model for athletes. In the third method, a rower’s AP CoM acceleration was estimated using a single IMU placed at the pelvis.

Experienced rowers rowed on an ergometer that was placed on two force plates, while wearing a full-body IMUs suit. Correspondence values between AP CoM acceleration based on IMU data (the three methods) and AP CoM acceleration obtained from force plate data (reference) were calculated. Good correspondence was found between the reference AP CoM acceleration and the AP CoM accelerations determined using IMU data in combination with the subject-specific mass model and the standard mass model (intraclass correlation coefficients [ICC] >?0.988 and normalized root mean square errors [nRMSE]?3.81%). Correspondence was lower for the AP CoM accelerations determined using a single pelvis IMU (0.877?Based on these results, we recommend determining a rower’s AP CoM acceleration using IMUs in combination with the standard mass model. Finally, we conclude that accurate determination of a rower’s AP CoM acceleration is not possible on the basis of the pelvis acceleration only.  相似文献   

17.
It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.  相似文献   

18.
It is believed that increasing the X-factor (movement of the shoulders relative to the hips) during the golf swing can increase ball velocity at impact. Increasing the X-factor may also increase the risk of low back pain. The aim of this study was to provide recommendations for the three-dimensional (3D) measurement of the X-factor and lower trunk movement during the golf swing. This three-part validation study involved; (1) developing and validating models and related algorithms (2) comparing 3D data obtained during static positions representative of the golf swing to visual estimates and (3) comparing 3D data obtained during dynamic golf swings to images gained from high-speed video. Of particular interest were issues related to sequence dependency. After models and algorithms were validated, results from parts two and three of the study supported the conclusion that a lateral bending/flexion-extension/axial rotation (ZYX) order of rotation was deemed to be the most suitable Cardanic sequence to use in the assessment of the X-factor and lower trunk movement in the golf swing. The findings of this study have relevance for further research examining the X-factor its relationship to club head speed and lower trunk movement and low back pain in golf.  相似文献   

19.
Braiding is not currently used in the production of golf shafts. The objective of this work was to develop, through a modelling process consisting of altering lamina sequence, a golf shaft, using braided laminas, which would have mass, stiffness and torque comparable to commercially available composite and steel shafts. A 2D conical braided composite model was previously developed and validated to predict elastic constants of braided closed meshed structures. Energy methods were used to calculate the stiffness and torque of shafts using prescribed industry approaches. Shaft mass was calculated based on geometry and density of constitutent materials. Modelled shafts had both braided and unidirectional layers and compared favourably with or were better than commercially available composite and steel shafts in terms of deflection force and twist angle; they had the same weight as composite shafts but were much lighter than steel shafts. If these findings are verified, braided composites would be a viable and effective approach to the design of future golf shafts.  相似文献   

20.
The effects of long-term Tai Chi exercise on body stability of the elderly during stair ascent under high and low illumination were investigated. Forty-five healthy elderly women were divided into three groups, namely, Tai Chi exercise group, brisk walking group and no-exercise control group. All the participants ascended a staircase, during which force platforms and a motion capture system collected the data. Under the high illumination, Tai Chi exercise participants exhibited higher loading rate and anteroposterior centre of pressure (COPap) displacement as well as a lower braking impulse than no-exercise group. Under the low illumination, Tai Chi exercise participants demonstrated higher COPap and mediolateral centre of pressure (COPml) displacements as well as lower braking and lateral impulses compared with no-exercise participants. The centre of mass (COM)ml sway in Tai Chi and no exercise participants were higher, the loading rates in Tai Chi and walking participants were higher, and the lateral impulse in no exercise participants was higher under low illumination than under high illumination. Thus, low illumination increases the risk of falling. Tai Chi participants increased their foot clearance, head inclination angle and COPap displacement under low illumination to increase their stability during stair ascent.  相似文献   

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