Kinetic and Kinematic Differences in a Golf Swing in One and Both Lower Limb Amputees

Evaluation of Weight Shift and X-Factor During Golf Swing of Veterans With Lower Limb Loss

OBJECTIVE

The purpose of this study was to assess the weight shift and X-Factor values of golfers with lower limb loss.

DESIGN

Veterans with above or below knee limb loss participated in a 3-day adaptive golf event hosted by the Department of Veterans Affairs. Professional golf instructors educated participants on proper golf swing mechanics, after which kinematic analysis of trunk rotation and kinetic analysis of weight transfer between the legs during the golf swing were evaluated using three-dimensional motion capture and force platforms.

RESULTS

Golfers with a trail leg amputation, regardless of level of limb loss, demonstrated superior weight shift, whereas golfers with lead limb amputation showed greater X-Factor values (all P < 0.05). Golfers with below knee limb loss demonstrated better weight shift strategies compared to those with above knee limb loss, regardless of which leg was amputated (i.e., lead or trail limb, all P < 0.05).

CONCLUSIONS

Sports rehabilitation programs should focus on increased weight bearing on the prosthetic limb to achieve appropriate weight shift and increased flexibility to increase X-Factor values. Participation in such programs can offer both physical and psychosocial benefits and may be a valid tool to increase the overall quality of life of veterans with lower limb loss.

Principal Component Analysis can Be Used to Discriminate Between Elite and Sub-Elite Kicking Performance

Contemporary descriptions of motor control suggest that variability in movement can be indicative of skilled or unskilled performance. Here we used principal component analysis to study the kicking performance of elite and sub-elite soldiers who were highly familiar with the skill in order to compare the variability in the first and second principal components. The subjects kicked a force plate under a range of loaded conditions, and their movement was recorded using optical motion capture. The first principal component explained >92% of the variability across all kinematic variables when analyzed separately for each condition, and both groups and explained more of the variation in the movement of the elite group. There was more variation in the loading coefficient of the first principal component for the sub-elite group. In contrast, for the second principal component, there was more variation in the loading coefficient for the elite group, and the relative magnitude of the variation was greater than for the first principal component for both groups. These results suggest that the first principal component represented the most fundamental movement pattern, and there was less variation in this mode for the elite group. In addition, more of the variability was explained by the hip than the knee angle entered when both variables were entered into the same PCA, which suggests that the movement is driven by the hip.

A biomechanical approach to investigate swing characteristics in elite golfers

BACKGROUND

The current study aims to compare the variability of positional control of the club in the starting period of downswing and the orientation of the clubface during impact in elite and intermediate golfers.

METHODS

Seven elite and 13 intermediate golfers were recorded by an eight-camera VICON motion capture system while putting with a pitch club. Six retro-reflective markers were attached to the club to build a biomechanical model for analyzing swinging movements. Group comparisons of outcome variables regarding the turning point, sweet spot, elevation angle (EA), and azimuth angle (AA) of the club head were made between the elite and intermediate players.

RESULTS

There were significant differences between groups in SDs of the location of the club tail along the x, y, and z axes at the turning point (x, p = 0.004; y, p = 0.015; and z, p = 0.035); the minimum distance between the center of the sweet spot and the ball at impact (p = 0.007); the EA (p = 0.001); and the AA (p = 0.001) of the club head. Results showed that the elite players displayed more converged locations of turning points, shorter distances between the center of the sweet spot and the ball at impact, greater EAs, and smaller AAs compared with those of the intermediate players.

CONCLUSION

These findings proposed a biomechanical approach of a practical way to observe swing behaviors. These findings suggest that the stability of locations of turning points is a golden reference for differentiating levels of golfers' performance.

Performance and Kinematic Differences in Putting between Healthy and Disabled Elite Golfers

Golfers with disability are limited in the execution of the full golf swing, but their performance in putting may be comparable because this stroke does not demand significant strength, balance and range of motion. Therefore, the aim of this study was to compare putting performance, kinetic and kinematic consistency between golfers with different disabilities and healthy athletes. The participants consisted of three disabled athletes (perinatal cerebral palsy, multiple sclerosis, below knee lower limb amputee) and three healthy golfers (age 34 ± 4.5 years, body height 178 ± 3.3 cm, body mass 83 ± 6.2 kg). The golfers’ movements were recorded by active 3D markers for kinematic analyses; the subjects performed 10 trials of a 6 m putting task while standing on separate force platforms placed under each lower limb. Putting performance was measured by the distance of the final ball position to the centre of the hole. ANOVA analyses did not show any differences in clubhead speed and total ball distance from the hole. The consistency of those two parameters expressed by the coefficient of variation (CV) was CV = 0.5% or better in both groups for clubhead speed and ranged from CV = 0.40 to 0.61% in healthy and CV = 0.21 to 0.55% in disabled athletes for total error distance. The main effect ANOVA showed differences in weight shift, hip and shoulder kinematics (p < 0.05) between healthy players and all players with disability. All disabled athletes shifted their weight toward the healthy side (towards the healthy lower limb) and alternated the end of the swing. The player with below knee amputation had the lowest range of motion in the shoulder joint during the putting stroke. The players with perinatal cerebral palsy and multiple sclerosis had the largest range of motion in the hips. Putting performance of disabled golfers was similar to healthy athletes. During training of disabled players, coaches should pay attention to the specificity of a particular disability when focused on putting performance. However, individual technique should achieve the same consistency as observed in healthy players.