Background and Purpose: Teenage golfers are still growing with immature body.
Selecting an appropriate golf-specific exercise for improving their physical characteristics may not only help for improving their performance, but also can protect them from injury. The purpose of this study was to examine the effects of a golf-specific exercise program on teenage golfers in physical characteristics and golf performance. Methods: Eighteen male teenage golfers (age: 14.8 ± 1.5 years, golf handicap: 9.9 ±5.7) who performed an 8 week golf-specific exercise program were selected for data analysis. Assessments for the pre and post-training testing included hip, torso, and shoulder strength, flexibility, balance, trunk movements, and golf performance. Results: Hip and hamstring flexibility improved significantly in 10 of the 14 measurements taken. Trunk rotation range of motion was not significantly improved. Bilateral shoulder internal rotation strength, left hip abduction strength, bilateral hip flexion and extension strength, and trunk flexion and extension strength were significantly improved. Bilateral one leg standing balance were significantly improved with eyes open and closed in 7 of the 12 variables analyzed. No significant difference was found in the maximal separation of upper and lower torso rotation angle and the maximal velocities of trunk movements during the down swing. Average ball speed increased from 143.4 ± 13.3 mph to 147.8 ± 11.2 mph (p = .004) with average club head speed increased from 102.0 ± 9.6 mph to 105.1 ± 7.2 mph (p = .004). Discussion and Conclusion: These results reveal that teenage golfers can improve golf performance by improving their strength, flexibility, and balance through a non-intensive golf-specific exercise program without experiencing too much stress. It is not certain whether kinematic variables other than the variables investigated in this study were affected by the improvements of physical
characteristics that result in increased club head speed and ball speed.
INTRODUCTION
Golf is not only a recreational activity that can improve physical health.[1, 2] It is becoming a competitive sport. With the performance improvements shown in world-class professional golfers receiving physical training, golfers and teaching professionals start to realize the contribution of conditioning exercise in golf. Improvements in physical strength, flexibility, and balance may optimize swing mechanics to improve golf performance and may prevent potential injuries.[3, 4] With the encouragement of children to join the golf game, special attention on the importance of physical conditioning in junior golfers is necessary.
Studies have demonstrated that golfers can benefit from strength, flexibility, balance, and warm-up programs.[5-10] Lennon’sprogram consisted ofstrength, movement, and balancetraining thatimproved golfer’sclub head speed.[10] In the programs of Hetu et al. and Thompson et al., club head speed increased 3-6 percent among golfers who received general flexibility and strength exercises for 8 weeks.[7, 8] A program introduced by Fletcher et al. included more vigorous strength exercises, plyometric and medicine ball exercises.[6] This program resulted in 1.5% increase in club head speed and 4.3% increasein driving distance.Jones’sflexibility training program improved golfers’trunk rotationsand hip extension rangeofmotion and had similarincreasein club head speed asFletcher’sprogram.[6, 9] Little was found in the literature regarding the effects of conditiong programs on the physical
characteristics, swing mechanics, and golf performance in junior golfers. Although physical training for adolescents may benefit their health and
improve sub-optimal physical condition for injury prevention, many of them could be hurt due to excessive training.[11] Vulnerable growth centers at the epiphysis,
articular cartilage, and apophysis in the immature skeleton could be injured during intensive training.[11, 12] Sports injuries could result in damage to the growth mechanisms and subsequent life-lasting damage.[13] To reduce risks of injury, it is necessary to provide appropriate intensity and frequency of training and appropriate equipment for adolescents. It was suggested that training for adolescents should emphasize on stretching to improve flexibility and low resistance strengthening with 6 to 15 repetitions per set, 1 to 3 set per session, 2 to 3 times per week for 20-30
minutes period.5 Meanwhile, weight lifting, power lifting, body building, and maximal lifts should be prohibited until growth and maturation are complete.[12]
A golf-specific training program introduced by Lephart et al. has been
determined to be effective on improving physical characteristics and golf performance in adult recreational golfers.[4] This program was designed based on the differences in physical characteristics (strength, flexibility, balance) between proficient golfers and golfers with higher handicap. It is also a home-based exercise program utilizing simple equipment including a piece of elastic resistance tubing and a balance mat. Intensity and frequency of the exercise program are also appropriate for the adolescents based on the recommendations in the literature.5 However, whether junior golfers can benefit from this program needs to be determined.
METHODS
Experimental Design
This study utilized a pretest-posttest experimental design. All subjects reported for two testing sessions prior to and after eight weeks of training. Each testing session lasted approximately 90 minutes.
Human Subjects
Twenty-seven junior golfers participated in the pre-training test and received instructions for the exercise training. Each subject provided written informed consent as approved by the University Institutional Review Board prior to participation. All subjects completed a general medical and orthopedic history questionnaire prior to participation to verify that they were healthy at the time of participation. All subjects were requested to keep their routine practice and not to participate in any other conditioning program during the time of this study. Twenty-one subjects completed eight weeks of training and came back for the post-training test (18 males and 3 females). Six subjects who were not able to come back for the post-training test were due to busy schedule of their arranged tournaments or withdrawal with personal reason.
Data collected from the eighteen male junior golfers were analyzed for this report. These golfers were all right handed. Average age and golf handicap of these golfers were 14.8±1.5 years and 9.9±5.7, respectively. Their body height and weight were 172.2±7.6 cm and 71.9±17.3 kg before eight weeks of training and 173.1±6.7 cm and 72.8±16.5 kg after eight weeks of training. There were no significant
differences in their height and weight between the pre-training and post-training tests.
Testing
Postural Stability Assessment
Postural stability was assessed using a Kistler force plate (Winterthur,
Switzerland) at the frequency of 100Hz. Each subject was asked to complete a single-leg standing balance test for each single-leg under two conditions (eyes open and eyes
closed). Three ten second trials were collected for each leg under each condition with barefoot standing on a balance mat. During the testing session, the subjects were instructed to remain as erect as possible with feet shoulder width apart and hands on hips. Subjects were instructed to focus on a target located in front of them at eye level during the testing session with eyes open. During the testing session with eyes closed, the subjects were instructed to focus on the target for balance first then close their eyes for data collection.
Strength Assessment
Trunk and Hip Flexibility Assessment
Flexibility measurements of the hip and hamstrings were assessed with a standard goniometer. The measurements of hip range of motion were standard procedures used in the clinical practice by a clinician.[14] Hamstring flexibility was measured in a supine position using the active knee extension test. The knee flexion angle with the thigh in the vertical position was measure. Trunk range of motions were assessed with the MotionMonitor 3D motion capture system (Innovative Sports Training, Inc., Chicago, IL) while subject actively rotate or bend their trunk to the end range of each direction in standing position.
Kinematic Analysis of Golf Swing
Trunk kinematics during the golf swing was collected at the frequency of 120Hz using the MotionMonitor 3D motion capture system integrated with the Polhemus LIBERTY electromagnetic motion tracking system (Polhemus, Colchester, VT). Two receivers were attached to thesubject’sskin atthefirstsegmentsofthe thoracic and sacral spine (T1 and S1) using double-sided tape and surgical tape for measuring the spinal position. General palpation is recommended by the
MotionMonitor manual for proper setup. The position and orientation of each receiver were computed relative to the transmitter which was placed behind the subject. The system was calibrated based on the manufacturer’s manual prior to use. A root mean square of 0.005 meters and 0.4 degrees was obtained in our laboratory for determining the accuracy of the receivers in measuring the position and orientation. After self directed warm-up and stretching, practice shots were provided prior to data collection. In order to represent the actual swing pattern experienced while playing, each subject hit golf balls with their own driver. Each subject hit 10 balls off an artificial turf mat into a screen with a simulated driving range integrated with the GolfAchiever II System (Focaltron Corporation, Sunnyvale, CA) showing real time ball flight and related information of each shot.
Golf Performance Assessment
Ball speed and club head speed were collected with the GolfAchiever II System. The GolfAchiever II System is a portable device that uses laser technology arranged in a portable L-Frame to capture, analyze, and display information related to each swing. The L-Frame features two opposing lasers, base and post, which saturate opposite laser detector assemblies on the post and base, respectively. Measurements of ball speed and club head speed were reported to be 99.9% accurate. Ten shots were collected from each golfer.
Exercise Intervention
The golf-specific exercise program used in this study was introduced by Lephart et al.[4] It is a home based program and was performed independently by the subject. The exercise program is divided into flexibility, strength, and balance
exercises. The exercises were performed three days per week for 8 weeks. Subjects were given all equipments needed during the exercise intervention, including an elastic resistance tubing attached to a handle and anchor piece for performing
for home reference. The exercise program is outlined in TABLE 1.[4]
Statistical Analysis
Differences in dependent variables were assessed with SPSS 12 (SPSS Inc., Chicago, IL). Two-tailed paired t-tests were used to determine significant differences in all dependent variables for the two groups. Statistical significance was determined at p < 0.05.
RESULTS
Average values, standard deviations, and p-values of physical characteristics, trunk kinematics, ball speed, and club head speed are listed in Tables 2-6.
Bilateral shoulder internal rotation strength was improved significantly, while bilateral shoulder external rotation strength showed no significant changes (Table 2). Bilateral hip strength in flexion and extension were observed to have significant improvements after training. As for the hip abduction strength, although both sides were improved, only left side showed significant increase. Strength of trunk flexion and extension was observed to improve significantly following the training protocol. In general, ROMs of bilateral hips were all improved significantly, except adduction and external rotation of the right hip (Table 3). Right hamstring flexibility improved significantly, while left hamstring flexibility did not improve significantly. Trunk rotation flexibility, however, did not show significant improvements bilaterally. Most balance variables under all conditions showed statistically significant improvements, but improvements in AP and ML sway on the right side under eyes closed condition, AP and ML sway on the left side under eyes open condition, and AP sway on the left side under eyes closed condition were not significant (Table 4).
No statistically significant improvements in the maximal velocities of trunk movements during down swing were observed (Table 5). Maximal X factor did not show significantly increased as well.
Statistically significant improvements were seen for ball speed and club head speed (Table 6). Average ball speed increased from 143.4 ± 13.3 mph to 147.8 ± 11.2 (p = .004) with average club head speed increased from 102.0 ± 9.6 mph to 105.1 ± 7.2 (p = .004).
DISCUSSION AND CONCLUSION
REFERENCE
1. Magnusson G: Golf: Exercise for fitness and health. World Scientific Congresss of
Golf, 1998.
2. Parkkari J, Natri A, Kannus P, et al.: A controlled trial of the health benefits of
regular walking on a golf course. Am J Med 2000; 109(2): 102-8.
3. Farrally MR, Cochran AJ, Crews DJ, et al.: Golf science research at the beginning
of the twenty-first century. J Sports Sci 2003; 21(9): 753-65.
4. Lephart SM, Smoliga JM, Myers JB, Sell TC, Tsai YS: An 8-week golf-specific
exercise program improves physical characteristics, swing mechanics, and golf performance in recreational golfers. Journal of Strength and Conditioning Research 2007; In press.
5. Fradkin AJ, Sherman CA, Finch CF: Improving golf performance with a warm up
conditioning programme. Br J Sports Med 2004; 38(6): 762-5.
6. Fletcher IM, Hartwell M: Effect of an 8-week combined weights and plyometrics
training program on golf drive performance. J Strength Cond Res 2004; 18(1): 59-62.
7. Hetu FE, Christie CA, Faigenbaum AD: Effects of conditioning on physical fitness
and club head speed in mature golfers. Percept Mot Skills 1998; 86(3 Pt 1): 811-5.
8. Thompson CJ, Osness WH: Effects of an 8-week multimodal exercise program on
strength, flexibility, and golf performance in 55- to 79-year-old men. J Aging Phys Act 2004; 12(2): 144-56.
9. Jones D: The effects of proprioceptive neuromuscular facilitation flexibility
training on the clubhead speed of recreational golfers. World Scientific Congress of Golf, St. Andrews, Scotland, 1998.
10. Lennon HM: Physiological profiling and physical conditioning for elite golfers.
World Scientific Congress of Golf, St. Andrews, Scotland, 1998.
11. Maffulli N: The growing child in sport. Br Med Bull 1992; 48(3): 561-8.
12. Harris SS: The child athlete. In: Birrer RB, ed. Sports Medicine for the Primary
Care Physician. Boca Raton, FL: CRC-Press, 1994; 175-187.
13. Larson RL, McMahon RD: The epiphysis and the childhood athlete. J Am Med
Assoc 1966; 196: 607-612.
14. Norkin CC, White DJ: Measurement of Joint Motion: A Guide to Goniometry,
Second ed: F.A. Davis Company, 1995.
SELF EVALUATION
Repetitions Duration Sets Stretching Exercises
Supine Hip Flexion 1 30 sec 1 Prone Torse Flexion 1 30 sec 1 Kneeling Lunge 1 30 sec 1 Seated Hip Rotation 1 30 sec 1 Seated Torso Rotation 1 30 sec 1 Seated Torso Rotation with Club 1 30 sec 1 Standing Lateral Bending 1 30 sec 1 Strengthening Exercises
Hip Abductions 10-15 Concentric and eccentric: 2 seconds each 3 Hip Adductions 10-15 Concentric and eccentric: 2 seconds each 3 Scapular Retractions 10-15 Concentric and eccentric: 2 seconds each 3 Resisted Back Swings 10-15 Concentric and eccentric: 2 seconds each 3 Resisted Down Swings 10-15 Concentric and eccentric: 2 seconds each 3 Resisted Through Swings 10-15 Concentric and eccentric: 2 seconds each 3 Abdominal Crunches 10-15 Concentric and eccentric: 2 seconds each 3 Balancing Exercises
Static Front Squat 1 30 sec 1 Single Leg Stances on Floor 1 30 sec 1 Single Leg Stances on Balance Mat 1 30 sec 1
Parts of the data from this study have been submitted to the American College of Sports Medicine 2007 Annual meeting at New Orleans, USA for presentation. A manuscript of this study is under preparation for publication.
Tsai, Y.S., Lephart, S.M., Chen, W.L., Wu, T.Y., Wu, P.L. The Effects of a
Validated Adult Golf-Specific Exercise Program on Teenage Golfers. 2007 American College of Sports Medicine Annual Meeting, New Orleans, LA (submitted)
Wu, T.Y., Wu, P.L., Tsai, Y.S. Relationship between Strength, Trunk Rotational Movements, and Ball Speed in High School Golfers. 2007 American College of Sports Medicine Annual Meeting, New Orleans, LA (submitted)
Tables
Table 1. Exercise Program
Table 2. Muscle strength
Pre-training Post-training
Mean ± SD Mean ± SD p-value Left shoulder external rotation (lb) 19.7 ± 5.2 20.7 ± 6.9 0.369 Right shoulder external rotation (lb) 23.0 ± 7.3 22.7 ± 6.1 0.845 Left shoulder internal rotation (lb) 27.7 ± 6.1 32.4 ± 6.7 0.000 * Right shoulder internal rotation (lb) 33.1 ± 8.2 37.3 ± 9.1 0.007 * Left hip abduction (lb) 61.3 ± 21.6 68.5 ± 21.4 0.010 * Right hip abduction (lb) 61.0 ± 23.4 66.3 ± 19.7 0.181 Left hip flexion (lb) 54.7 ± 12.6 65.8 ± 10.4 0.001 * Right hip flexion (lb) 55.9 ± 12.1 71.7 ± 15.0 0.000 * Left hip extension (lb) 54.5 ± 11.7 67.8 ± 21.6 0.002 * Right hip extension (lb) 52.2 ± 11.9 69.9 ± 25.2 0.002 * Trunk flexion (N) 511.3 ± 108.9 567.3 ± 93.4 0.001 * Trunk extension (N) 788.3 ± 236.2 943.7 ± 256.3 0.000 * * indicates significant differences between Pre- and Post-training tests
Table 3. Flexibility (range of motion)
Pre-training Post-training
Mean ± SD Mean ± SD p-value Left hip flexion (º) 122.5 ± 7.2 127.9 ± 7.8 0.004 * Right hip flexion (º) 119.5 ± 7.3 129.0 ± 8.4 0.000 * Left hip extension (º) 18.8 ± 4.9 26.5 ± 4.6 0.000 * Right hip extension (º) 18.0 ± 4.6 26.7 ± 4.8 0.000 * Left hip abduction (º) 27.6 ± 9.9 34.8 ± 13.9 0.020 * Right hip abduction (º) 26.7 ± 10.4 33.4 ± 9.8 0.001 * Left hip adduction (º) 12.0 ± 5.2 14.4 ± 6.4 0.051 Right hip adduction (º) 10.6 ± 6.1 11.9 ± 6.7 0.158 Left hip internal rotation (º) 32.6 ± 11.0 42.2 ± 7.5 0.000 * Right hip internal rotation (º) 32.7 ± 12.0 48.8 ± 8.2 0.000 * Left hip external rotation (º) 37.6 ± 6.1 54.1 ± 8.6 0.000 * Right hip external rotation (º) 38.7 ± 6.6 42.4 ± 8.6 0.096 Left knee flexion (hamstring) (º) 25.7 ± 6.3 23.8 ± 9.8 0.302 Right knee flexion (hamstring) (º) 28.8 ± 8.1 24.4 ± 9.6 0.018 * Left trunk rotation (º) 51.3 ± 11.0 56.4 ± 7.6 0.054 Right trunk rotation (º) 48.1 ± 9.8 50.7 ± 10.7 0.242 * indicates significant differences between Pre- and Post-training tests
Table 4. Balance (standard deviation of ground reaction force)
Pre-training Post-training
Table 5. Trunk kinematics during downswing and maximal X factor Pre-training Post-training
Mean ± SD Mean ± SD p-value Max. upper torso axial rotation velocity (º/s) 1092.1 ± 280.7 1047.5 ± 183.3 0.396 Max. lower torso axial rotation velocity (º/s) 507.3 ± 68.2 533.3 ± 93.7 0.083 Max. spinal rotation velocity (º/s) 934.4 ± 274.4 909.1 ± 166.7 0.672 Max. flexion velocity (º/s) 357.7 ± 121.5 394.4 ± 164.0 0.377 Max. side bending velocity (º/s) 621.3 ± 140.6 689.9 ± 101.1 0.069 Max. X factor (º) 57.0 ± 9.9 57.9 ± 14.3 0.857 Max. X factor is the maximal separation angle between the upper (T1) torso axial rotation angle and lower (S1) torso axial rotation angle.
Table 6. Ball speed and club head speed
Pre-training Post-training
