The Sequence Of Hip And Selected Upper-Extremity Joint Movements During The Golf Drive (P2)
There was considerable variability in the angles measured for both the flexion-extension and abduction-adduction movements of the left wrist (see Figures 7 and 8). At the peak of the backswing, the mean value for flexionextension movement was 187.7 degrees, which shows slight hyperextension. The staneard deviation was 25.8 degrees. The values ranged from 131.r degrees to 221.7 degrees. The mean position at ball 7ontact was 167.8 degrees indicating slight flexion. Between the twenty-two and one-half degree vertical positions of the left arm, however, four subjects extended their left wrists while six subjects flexed them. Most of the action of the left wrist took place after the 6 left arm had passed the forty-five degree reference oosition.
The mean angle for the left wrist was 208.4 degrees indicating considerable abduction at the peak of the backswing. There was little variability and all subjects followed a similar pattern of movement. The mean value for the total amount of adduction when the left arm was moved from the peak of the backswing to ball contact was 33.3 degrees The major portion of this action occurred in the last part of the swing. From the left arm position of twenty-two and one-half degreer to vertical, there were 13.1 degrees of adduction, from the vertical left arm position to ball contact
The hip movements of the subjects varied. In this study, only those movements that were made in a horizontal plane passing through the hips were measured. Some subjects raised or dipped their hips during parts of tkl,.! swing. Such actions were not recorded.
The hip analyzer was affixed to the posterior aspects of the pelvis by means of a belt that encircled the hips. The recordings of hip action were representative of two things; a positioning of a midpoint of the posterior portion of the perimeter around the hips and the angle formed in a horizontal plane between an imaginary line crossing the superior iliac crests and intended line of flight of the golf drive. The movements measured are referred to as lateral sliding of the hips and horizontal turning of the hips.
The use of the feet and their role in the golf swing was not part of this study. However, it was important to have a general understanding of the positioning of the feet because this could possibly affect other body actions. The manner in which each subject positioned his feet for each shot was recorded through the motion picture filming. These tracings were collectively stud;.ed and the following generalizations were made; six subjects used an even stance. three subjects used a closed stance and one subject used an open stance. Seven of the ten subjects toed out with the left 7 foot while the other three sajorLs held it square. Six subjects toed out with the right foot and the other four held the left foot square. Eight subjects had their heel on a line parallel to the line of flight.
Five of the nine subjects demonstrated greater lateral sliding between the ninety degree and the forty-five degree positions of the left arm than between any other two adjacent reference positions (see Table 1). These five subjects registered an average of 40 percent of their total hip movement between these two reference points. The mean amount of lateral sliding for all subjects from the peak of the backswings through to ball contact was 11 inches. There was considerable variability as indicated with a standard deviation of 3.21 inches. The range of movement was from 14.7 inches to 4.1 inches.
The greatest amounts of hip turn, 13.1 degrees, and lateral sliding, 3.9 inches. were recorded between the horizontal and forty-five degree reference positions. However, values of 11.4 degrees of hip turn between the forty-five And twentytwo and one-half degree left arm positions and 12.8 degrees between the twenty-two and one-half and vertical positions were not greatly dissimilar (see Table 2, page 20 ). High correlations were found between the amount of lateral sliding and the amount of horizontal turning of the hips. The mean position of the hips at the peak of the backswing was 30.9 degrees (clockwise movement), while the position at contact was minus 13.2 degrees (counterclockwise movement). There was a mean amplitude of 44 degrees.
High values for computed standard deviations indicated considerable variability among subjects relative to hip action.
The findings in this study indicate that general patterns of movement throughout the golf swing vary among subjects. Therefore, the hypothesis that there is a specific pattern of of motion, that is, a model swing which is applicable to all performers is not supported. The findings do indicate that certain body movements are perforred by all low handicap golfers but that these movements are not necessarily completed in the same sequence by all golfers when performing the total act. Conclusions relative to such findings are as follows:
- The standard deviations for the movements of each subject on repeated trials were low. It is concluded that a low handicap golfer has little variability in the movement pattern by which he executes successive
- All subjects demonstrated extensive adduction of both wrists and flexion of the right wrist just before ball contact. These findings support the “delay hit” concept reported in the literature.
- The findings reveal a high correlation between lateral sliding and horizontal turning of the hips. Furthermore, the hip movements began with the initiation of the downswing and continued through ball contact with no appreciable differences in the amount of movement at the various reference positions. It is therefore concluded that combined hip movements performed at a constant rate throughout the swing are characteristic of low handicap golfers. However, the timing of hip movement was individualistic.
- The findings revealed a high variability among the subjects in the amount they circumducted their left arm
in a clockwise fashion (“peaked to a backswing’) . It is therefore concluded that low-handicap golfers have considerable variability in the amount of backswing taken prior to the downswing
- The conclusions reached relative to specific body actions during the downswing are as follows.
- The left elbow is near full extension at ball contact.
- At the moment of ball contact, the left elbow is extended to a c;reater degree than
- There is a great deal of variability among golfers in the amount of rotation of the forearms during the golf swing
- There is great deal of variability in the flexion-extension positioning of the left wrist during the downswing; however, there is less variability among golfers at ball contact. At this point, the left wrist is near full extension.
- When ball contact is made, the long axis of the left arm is slightly beyond the vertical position.
- Low – handicap golfers assue a variety of positions while addressing the ball for the drive in golf.
The findings in tnis study suggest several implications concerning the execution of the golf swing. Although it is concluded that there is no ‘model swing for all golfers,.it is implied that of the body motions studied. certain of them are essential to a successful golf drive. Therefore, teachers and players should be aware of them. Those movements or positionings are:
- The left arm is near full extension at ball contact.
- Both wrists are brought to full extension and neutral between adduction and abduction at ball contact.
- The major portion of right elbow extension occurs after the left arm has reached the 22.5 degree reference position and continues through ball contact.
- At the moment of ball contact the left elbow is extended more than the right.
- The function of both forearms is individualistic and probably dependent upon other variables such as grip, stance ar stature.
- The major portion of wrist action (adduction of both wrists and frexion of the right wrist) occurs after the left arm has reached the 22.5 deciree reference position and continues through ball contact
It is recommended that the technique and im;trumentation used in this study be employed to invest.:.gate the same body actions:
- at selected reference points during other shots in golf.
- of different caliber players.
- of low-handicap players grouped according to physical size.
It is recommended that a more complete analysis of the same joint actions studied be conducted after the left arm passes the twenty-two and one-half degree position. This analysis should include measures of linear velocity in order to more completely understand the summation of forces.
It is recommended that the effects of the manner of hand positioning (grip) upon the actions of the elbows and wrists be analyzed. Some of the instrumentation and technique used in this study could be employed.
It is recommended that a study be conducted to determine the effects of different stances upon the actions of the elbows, wrists and hips.
It is recommended that the technique and instrumentation developed in this study to determine wrist action be used in the analysis of other athletic activities.
It is recommended that the hip analyzer be used in the analysis of hip action in other types of athletic performance.