Sung Eun Kim

All Publications

• Potential biomechanical risk factors on developing lead knee osteoarthritis in the golf swing. Scientific reports Kim, S. E., Pham, N. S., Park, J. H., Ladd, A., Lee, J. 2022; 12 (1): 22653

  Abstract

  The load on the lead knee joint during a golf swing is greater than that observed during gait. However, current evidence regarding golf swing biomechanics for risks associated with knee osteoarthritis (OA) is limited. Therefore, this study investigated golf swing styles associated with knee adduction and abduction moments, which are considered to be crucial loading regions of the medial and lateral compartments of knee OA, respectively. Thirteen professional male golfers performed five shots using a 5-iron club, and their swings were recorded using a motion capture system with two force platforms for the feet. A regression analysis was performed to calculate the correlation coefficients between the peak knee adduction and abduction moments of the lead leg and varus/valgus angle, toe-out angle, stance width, weight transfer, and shoulder sway. Swinging with a narrower stance width at address (r =  - 0.62, p = 0.02) with more weight shift (r = 0.66, p = 0.014) and shoulder sway (r = 0.79, p = 0.001) towards the target during the downswing were associated with a higher peak knee adduction of the lead leg, whereas a greater valgus angle at address (r = 0.60, p = 0.03) was associated with a higher peak knee abduction of the lead leg. Based on these findings, we anticipate future research to support postural changes, particularly a wider stance width and restricted shoulder sway for golfers who are classified to be at high risk of developing medial compartment knee OA, as well as a lower valgus (tibial medial tilt) angle at address for those classified to be at high risk of developing lateral compartment knee OA.

  View details for DOI 10.1038/s41598-022-27160-4

  View details for PubMedID 36587045

• Golf swing in response to anteroposterior ball position INTERNATIONAL JOURNAL OF SPORTS SCIENCE & COACHING Kim, S., Lee, J., Lee, S., Lee, H., Lee, S., Shim, J. 2022

  View details for DOI 10.1177/17479541221137672

  View details for Web of Science ID 000882769100001

• Reducing Knee Joint Load during a Golf Swing: The Effects of Ball Position Modification at Address JOURNAL OF SPORTS SCIENCE AND MEDICINE Kim, S. 2022: 393-400

  Abstract

  As the modern golf swing has changed, the incidence of knee pain in professional golfers is increasing. For those with previous knee injuries, developing a golf-swing modification that reduces knee loading may be necessary to recover performance after injury. The purpose of this study was to test whether ball position modification reduces knee joint load in a golf swing. Thirteen male professional golfers participated in the study. Golf swings were captured using a three-dimensional motion capture system and two force platforms, with conditions for self-selected ball position and eight additional ball positions. Knee internal rotation and adduction moments were calculated. The length of one golf ball (4.27 cm) backward ball position (closer to the golfer) significantly reduced the peak internal rotation moment of the lead knee (- 13.8%) (p < 0.001) and the length of one golf ball (4.27 cm) away from the target ball position significantly reduced the peak adduction moment of the lead knee (- 11.5%) (p < 0.001) compared with that of the self-selected ball position. Based on these observations, we conclude that the backward ball position modification might be suggested for golfers with anterior cruciate ligament injuries, and the away from the target modification might be suggested for golfers with medial compartment knee osteoarthritis.

  View details for DOI 10.52082/jssm.2022.393

  View details for Web of Science ID 000834953200001

  View details for PubMedID 36157394

  View details for PubMedCentralID PMC9459761

• Small changes in ball position at address cause a chain effect in golf swing SCIENTIFIC REPORTS Kim, S., Lee, J., Lee, S., Lee, H., Shim, J., Lee, S. 2021; 11 (1): 2694

  Abstract

  The purpose of this study was to investigate how the ball position along the mediolateral (M-L) direction of a golfer causes a chain effect in the ground reaction force, body segment and joint angles, and whole-body centre of mass during the golf swing. Twenty professional golfers were asked to complete five straight shots for each 5 different ball positions along M-L: 4.27 cm (ball diameter), 2.14 cm (ball radius), 0 cm (reference position at preferred ball position), - 2.14 cm, and - 4.27 cm, while their ground reaction force and body segment motions were captured. The dependant variables were calculated at 14 swing events from address to impact, and the differences between the ball positions were evaluated using Statistical Parametric Mapping. The left-sided ball positions at address showed a greater weight distribution on the left foot with a more open shoulder angle compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. These trends disappeared during the backswing and reappeared during the downswing. The whole-body centre of mass was also located towards the target for the left-sided ball positions throughout the golf swing compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. We have concluded that initial ball position at address can cause a series of chain effects throughout the golf swing.

  View details for DOI 10.1038/s41598-020-79091-7

  View details for Web of Science ID 000616811600001

  View details for PubMedID 33514759

  View details for PubMedCentralID PMC7846748

• Biomechanical Effects of Ball Position on Address Position Variables of Elite Golfers JOURNAL OF SPORTS SCIENCE AND MEDICINE Kim, S., Koh, Y., Cho, J., Lee, S., Lee, H., Lee, S. 2018; 17 (4): 589-598

  Abstract

  The purpose of this study was to investigate address position variables in response to changes in ball position in golfers. Eleven male professional golfers were instructed to perform their golf swing. A three-dimensional motion analysis system, with eight infrared cameras and two force platforms, was used to capture the address positions. A golf ball has a diameter of 4.27 cm, and a radius of 2.14 cm. Even small movements of ball position in the mediolateral (M-L) and anteroposterior (A-P) directions significantly changed the address position. When the ball was moved to the left, the shoulder rotation and club-face aim rotated toward the left of the target, and the left vertical ground reaction force increased. When the ball was moved to the right, the opposite findings were observed. When the ball was moved closer, the trunk, hip, knee, ankle, and absolute arm angle extended; the lie angle of the golf club increased; and the center of pressure moved toward the posterior direction. These changes were reversed when the ball was moved further away. The M-L ball position critically changed the address positions of the upper extremities in the horizontal plane, and the A-P ball position critically changed the angles of whole body parts in the sagittal plane. Furthermore, club-head kinematics at impact such as club-face aim, club path, and angle of attack were significantly changed in the M-L ball position; and club-head speed and angle of attack were significantly changed in the A-P ball position. This in-depth understanding of the address position in association with the ball position could provide valuable data for swing coaches when finding a golfer's optimal address position.

  View details for Web of Science ID 000450645700010

  View details for PubMedID 30479527

  View details for PubMedCentralID PMC6243633