Golf swing is a sports motion that that involves a gyratory action of the body that generates force used to hit the ball. The force travels through the hands arms and the club shaft to reach the ball (Gryc, Zahalka, Maly, Mala&Hrasky, 2015). The anatomy of a golf swing is important for various reasons. The full swing has certain physical demands that golfers need to know to improve their performance (Eskofier,Tuexen, Kugler,Jensen&Wright, n.d). Such explains the reasons for understanding the muscles and joints involved. Training programs study these and formulate exercises that can improve them (Cole&Grimshaw, 2016). It is also important to understand the anatomy of a golf swing to avoid injury. Take an example of the follow-through phase. Under high velocity, golfers risk injuring their shoulder joints, and other swing related muscles if they do not have enough strength and power to stop the kinetic force. Golf as a game, has its share of injuries. Knowledge of the swing anatomy helps physiotherapists in ensuring injured parts regain their functionality (Esperon, 2014). Evans and Tuttle(2015) also indicate that research in the motor learning, biomechanics and motor control have increased the bodily necessities of the game. It has provided knowledge that when used in the exercise programs, improve performance among the golfers (Evans&Tuttle, 2015; McNally&McPhee, 2018; Beak et al., 2013). Part of knowledge of a golf swing anatomy is understanding the movement anatomy. This is all described in the following sections. There are two phases of the golf swing described. The analysis shows that the phases utilize similar muscles and joints, contracting, or extending to achieve the intended purpose. In the backswing, the body moves to load energy. In the downswing, the body mores to exert kinetic energy on the ball. Lastly, in the follow-through phase, the muscles and joints now act to stop the kinetic movement created by the backswing and downswing.
The Golf Swing
There are three phases in the golf swing. There is the preparation phase which consists of the posture, the grip, the ball position and the stance. There is the execution phase which consists of the downswing and the backswing. Lastly, there is the follow-through, or the recovery phase. Since this paper is focused on movement analysis, it will leave out the first phase and discuss the second and third phase. Figure 1 has the illustration of all the phases.
Courtesy of Lesiuta (n.d)
The Execution Phase
This phase consists of the backswing and the downswing. Golf happens in two planes; that on the backswing and on the downswing. It also evolves around an up-down movement around the body and the lateral side to side movement (Craig &Vince, 2018).
The purpose of this swing is to establish a balance at the top of the swing. In this swing, the hands, clubhead, and the shoulders start in one motion. At this point, the golfer is at a stance and the weight of the feet shifts laterally to the rear foot from the front foot. The shifting of the weight increases hip rotation range. The arc of the swing is also flattened by it. When the weight shifts to the rear foot, the left hip laterally rotates moving the hip away from the ball’s flight (Bobby, 2014; Craig &Vince, 2018). The shoulders coil at the top of the backswing. The arms extend, and the hands swing high.
Figure 2: An illustration of the Backswing
Courtesy of Craig&Vince (2018)
Muscles and Joints Involved
In the backswing the following muscles are involved. Deltoids contract, latissimus dorsi contract extend, and trapezius contract and extend. Figure 3 below illustrates the positions of the muscles. The right posterior deltoid contracts to ensure shoulder rotation during a backswing. The left pectoralis allows for interior rotation during a backswing. Synergistic muscles involved are; triceps, biceps, obliques, brachialis, rectus abdominis, and pectoralis major.
Joint actions in this phase are; wrist rotation, shoulder rotation and circumduction, hip rotation, elbow flexion, and trunk rotation (Craig &Vince, 2018). The shoulder joint twists to the right and up. The wrist joint is a synovial joint and a condyloid articulation. It therefore allows a great deal of mobility. They are pointed downwards at the beginning of the stroke. At the top of the backstroke, they will be flexed upwards (Craig &Vince, 2018).
Figure 3: Backswing with Muscles Involved
Courtesy of Maddalozzo (1987)
The downswing is initiated by the hips’ rotation. At the same time of the rotation, weight is transferred from the rear foot to the front foot laterally. Such a move flattens the swing arc and improves accuracy. It is a reaction to the backswing and it is in the same plane. When the arms swing, the shoulders move. When the hips rotate, they unwind the upper part of the body, the arms, the shoulders, and the hands which then flow easily into the swing. It ends at impact. At this point, the force produced by the other body parts and the trunk straighten the wrist and produce a maximum hitting effort (Craig &Vince, 2018).
Figure 4: An illustration of a Downswing
Courtesy of Craig &Vince (2018)
The muscles involved in the downswing are the same as those in the backswing, except they act in the opposite direction. In this swing, the left posterior deltoid contracts to ensure shoulder rotation during a backswing. The right pectoralis allows for interior rotation during a downswing. The elbow extends, and the right arm adducts. Other muscles involved are; the trapezius which contract and extend, and the latissimus dorsi which also contract and extend (Craig &Vince, 2018). The synergist muscles are the same; biceps, triceps, brachialis, obliques, rectus abdominous and pectoralis major. Downswing is also characterized by shoulder rotation and circumduction, trunk rotation, wrist rotation, hip rotation, and elbow flexion. The shoulder joint twists to the left and down. The wrist joint will be bent down again during this swing. The illustrations of the muscles and joints are in figure (Craig &Vince, 2018).
Figure 5: The Downswing Illustration of Muscles Involved
Courtesy of (Maddalozzo, 1987)
The Follow-Through Phase
When it gets to this phase, the effort is lessened. The right arm starts rotating leading to the right arm climbing over the left. The golfer’s head now rotates forward as it is pulled up by the swing momentum and the turning trunk (Craig &Vince (2018).
Figure 6: Follow Through Illustration
Courtesy of Craig &Vince (2018)
Muscles and Joints Involved
During the follow-through phase, the deltoids still contract, the latissimus dorsi contract and extend, the tibialis anterior extend, gastrocnemius contract and the trapezius contract and extend. The muscles work to slow down the body though eccentric contractions. These muscles steady the shoulder blade to the rib cage and spine. They act to protect the shoulder joint which may be damaged under high velocity if it reaches its end range of motion (Human Kinetics, n.d). There are two more synergy muscles added to the list found in the execution phase. These are; the quadriceps and hamstrings. These two synergists create stability at the knee joint and holds the golfer in a bent position (Alex, 2016) holding him in the bent position Along with the rectus abdominis, obliques, psoas major and transversus, the muscles produce force from their maximum power to decelerate the body (Human Kinetics, n.d).In this phase too, joint actions involved are similar to those found in the execution phase. The only difference is on the additional joint actions such as the ankle rotation, knee flexion and plantar flexion. The shoulder joint continues the flow by turning up and to the left. The wrist joint is then flexed up again at the top of the flow through.
In the two phases described, the difference is in the additional synergy muscles and joints. In the backswing and downswing, the extra synergy muscles used are the quadriceps and hamstrings. There are extra joints too. These explain the difference in role of these muscles and joints in the phases. Backswing is all about muscle loading which amounts to storage of potential energy.The Downswing is about the release of the potential energy. In all these, there are muscle actions that generate such actions. After a speed has been established and the golfer has hit the ball, the body again has to stop. The follow-through phase is where the muscles now act to decelerate the body. With high velocity, the shoulder joint could reach its end range of motion. The follow-though muscles and joint actions all act to stabilize the body.The details of how the muscles and joints work together to produce the swings is evidence of why such knowledge is nowadays used to develop training programs. It also shows how they can help therapists and even the golfers to improve in their accuracy, speed and consistency in performance.