During the swing NM control is important in for proper technique and providing sufficient muscle force to stabilise the

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3 Highly coordinated action with excellent kinematics requiring a small amount of energy from muscles to provide sufficient energy for each shot. (Shibayama, 1983) During the swing NM control is important in for proper technique and providing sufficient muscle force to stabilise the vertebral column. (Cole and Grimshaw, 2005) Successful swings produce a rotary movement rather than an up down or lateral bending movement. (Cowan, 2013) There is no one perfect swing for everybody, but everybody has one perfect swing. (Peter Kostis) No one size fits all : individual physical attributes allow for individual variations on successful mechanics. (Nagao & Sawada, 1974)

4 Classic Swing Modern Swing

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6 Arm Swing FullBody Swing (Classic) (Modern) Velocity of club at impact (m/s) Force at impact (N) Energy at impact (J) Power (W) Momentum (kg*m/s) (g /) Ball Speed (after impact) (m/s) (Adapted from Won, 2011)

7 Factors Influencing Evolution of the Golf Swing Equipment changes Golf course design and condition Strength and conditioning

8 Turf management/ Egronomy Bunkers/Water hazards Robert Trent Jones

9 Physical conditioning is now an integral part of an elite player s routine in terms of creating explosive power through wide ranges of motion. (Wells et al, 2009) Club head velocities exceed 160 km/h and it takes only 0.2 sec to accelerate the club to this speed which is done times per round. (Alvarez et al, 2012) Research has shown that golf performance can be improved by weight training, plyometric programming, and combined flexibility and strength training. (Doan, 2006; Fletcher, 2004; Hetu, 1998; Jones 1999; Lephart, 2007; Thompson, 2007; Thompson 2004; Wescott, 1996)

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11 An efficient swing requires the hip spine angle to remain constant. This in turn requires good trunk and hip rotation. (Booth and Forrest, 1999). Amateurs shorten the swing to counteract rotation limitations or lumbar stresses. (Bulbulian, li 2001) (White and Panjabi, 1990)

12 4 main forces in the golf swing: - Compression - AP or PA shearing - Lateral bending - Torsional (Hosea et al, 1990) Cancellous bone absorbs 50% of compression, facets absorb 20% and nucleus polposus and annular fibers absorb remainder. (Hosea, 1990) Facets resist 50% of PA shearing, remainder IVD. (Boos, 2008) Torsion created as a result of rotation along long axis of spine. Limited by facets posteriorly and annulus anteriorly. (Oliver, 1991)

13 Compression loads of 8 times body weight in professional golfers approx 7,500N. (Hosea and Gatt, 1996) Cadaveric studies showed disc prolapse with loads of 5,450N. (Adams and Hutton, 1988) Only 2 or 3 degrees of intersegmental rotation can produce microtrauma in the lumbar facet joints. Peak shear loads of almost 600N seen during swing of amateurs, with shear loads of 570N capable of producing pars fractures in cadavers. (Cryon and Hutton, 1978)

14 Weight distribution Straight spine, hip flexion Relax knees 15 degrees Weight over front of ankles. Spine angle. Right hand lower than left. This habitual posture results in some golfers demonstrating a scoliosis concave to the right. (Booth, 2005) Base of support no wider than shoulder width. (Puyear, 2006)

15 The grip allows 2 hands to function as 1 unit. Right wrist extends and radially deviates in backswing. (Campbell, 2013) Left wrist radial deviation in backswing. (Campbell, 2013) Grip pressure

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17 Shoulder Rotation 91 degrees Pelvis Rotation 43 degrees

18 External rotation and retraction of the right shoulder. Flexion, adduction, internal rotation, and protraction of the left shoulder. Internal rotation of the right hip, external rotation of the left hip. Large shoulder turn with limited hip turn. The pelvic muscles provide a stable base for the trunk to rotate. PGA tour Pelvic rotation 35 50degrees Average 43 degrees Shoulder rotation degrees Average 91 degrees This increases potential energy stored at the top of the backswing by using visco elastic properties of soft tissue and stretch shortening reflex. Coiling the shoulders against a stable lower body increases the X factor to achieve maximum stored potential energy therefore maximum power, clubhead speed and distance. Elite players transfer weight to their R foot during the backswing. (Kawashima, 1999; Wallace et al, 1990; Koenig et al,1994)

19 F, ABD, ER FADD F, ADD, IR 1 2 Stable Base IR ER Stable R Knee 3 4

20 Right Left Upper trap 52% Subscapularis 33% Middle trap 37% Serratus30% Semimembranosus 28% Long head of biceps femoris 27% Erector spinae 26% Abdominal oblique 24%

21 The point between the backswing and the downswing is the transition. ii The lower body initiates the downswing while the upper body and club continue the backswing. (Hellstrom, 2009) The initial weight shift is achieved by shifting hips linearly towards the target (Cochran, 1968; Hay, 1973, Hogan, 1957) and by supinating the left foot which moves the left knee towards the target. (Leadbetter, 1990) Weight shift is from inside the right heel to the inside of the ball of the left foot. The transition finishes when the club has stopped moving clockwise. Here the hips are at 45 degrees, shoulders 100 degrees. High eccentric loading of the left latt and left posterior rotater cuff. Also high eccentric loading of the right pec, right EO and left IO.

22 Starts at top of the backswing: ends with club horizontal to ground. The golfer pushes in an anterior direction with his left foot and a posterior direction with the right foot generating an anticlockwise torque. (Williams 1983; Carlsoo, 1967) As the downswing begins the weight shift continues onto the left foot by moving hips towards the hole (Richards, 1985). The right hip extensors and abductors, in conjunction with the left adductor magnus, initiate pelvic rotation during downswing. (Bechler et al, 1995) This force is passed through the core. Additional forces are generated by obliques, quads, hamstrings and low back muscles. This produces an anticlockwise torque of the upper pendulum through activity of pec major, lattissimus and RC in both shoulders. The left latissimus dorsi helps pull the golfer onto his lead side while counteracting the force generated by the pecs.

23 Left leg Objective is to position the left knee over the outside aspect of the left foot. Thisputs the golfer in proper alignment for the quad and gluts to contract and for the hip muscles to contract to create both lateral stability and internal rotation in the hip. R leg The right leg uses the gastrocnemius, quads, adductor magnus, hamstrings, and glutmaximus, to create triple extension to help drive the golfer s weight onto the left side.

24 Right Left Pec major 64% Rhomboid 68% Serratus 58% Middle trap 51% Glut max 100% Biceps femoris 78% Vastus lateralis 88% Adductor Magnus 63%

25 Right gluts are very active. Right biceps femoris contracts strongly to aid weight transfer to the left side. The left pelvic muscles provide stability and a pivot point for left lumbopelvic rotation. Weight transfer is enhanced by VL and add mag. Left thoracic and scapular rotation around trunk in an anticlockwise direction i results in large activity i of the left medial scapular stabilisers. High activity of the right pec major for internal rotation and flexion, and upper serratus contracts t for scapular protraction. ti By the time the club is approximately horizontal the wrist is in maximum dorsiflexion and the muscles of the forearm are under tension. Powered by pec major subscap and latt dorsi of both arms Powered by pec major, subscap and latt dorsi of both arms. (Jobe.1986; Moynes 1986)

26 At impact the anticlockwise il i torque of the feet has ended. ddboth hfeet apply a shear force to slow down foot motion towards the hole. (Stover, McCarroll and Mallon, 1994). The left foot is supporting 85 90% of the load. There is a valgus stress to the right knee. (Richards,1985). Left elbow extensors and right forearm flexors fully contract. (McCarroll, 1985) A downforce of 150% of total body weight is generated in players exhibiting good core control. The lower body muscle activity is similar to the downswing where the left side acts as a stable base and the right side rotates around it.

27 Right Left Pec major 93% Pec major 93% Serratus 69% Levator scapulae 62% Abdominal oblique 59% Glut medius 51% Biceps femoris 83% Glut max, vastus lateralis 58%

28 The pecs are the most active. The right pec continues the activity achieved in the downswing. The left pec maintains an eccentric contraction to control L arm abduction and ER. The right serratus is active to protract the scapula. The left lev scap is active to help with scapular tilting. The left lateral leg and lumbopelvic stabilisers are strongly activated. Right external oblique is active in order to assist left rotation of the trunk.

29 During the downswing the wrists remain radially deviated d( (negative torque), preventing the lower pendulum from opening. (Fleisig, 1984) Whenthe club is approx horizontal the wrists ulnar deviate. The left arm supinates, the right arm pronates and flexes. This is known as the flexor burst as the right wrist flexors contract powerfully. If there is a sudden decrease in clubhead acceleration (e.g. hitting the ground) there is a sudden change from concentric to eccentric contraction in the wrist flexors. This can lead to injuries!

30 From impact to horizontal: during this phase deceleration of the trunk occurs through eccentric contractions. To decelerate the pendulums subscap continues to be active. Latt dorsi and pec major of both arms are active at reduced levels. The latissimus dorsi and scapular stabilisers as well as the muscles of the rotator cuff help protect the shoulder joint from approaching its end range of motion under high velocity. (Vaughan, 1981) After impact the left arm continues to supinate while the right arm continues to pronate. The lumbar spine rotates and hyperextends. Hip rotation is complete. Maximal left hip IR at this stage. Both the right hip internal rotators and the left hip external rotators are active. Pec major continues to be very active during this phase. The obliques are also very active.

31 Right Left Pec major 74% Pec major 74% Subscap 64% Infraspinatus 61% Glut medius 59% Abdominal oblique 51% Biceps femoris 79% Vastus lateralis 59%

32 From club bhorizontal to the ground and ends with ihcompletion of the swing. Muscle activity in this phase decreases. The right serratus aids protraction of the right scapula around the trunk. During follow through a number of muscles are loaded eccentrically to aid deceleration: right posterior RC, left pec, left EO and right IO. Finish in hyperextension: reverse C curve.

33 Right Left Subscap 56% Infraspinatus 40% Serratus 40% Pec Major 39% Vastus Lateralis 40% Glut medius 22% SM & VL 40% Add Mag 35%

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35 The swing requires rapid GH movements through a large range of movement. (Batt, 1992) Golfers use both sides of their body and so should strengthen left RC to at least the levels of the right. (Pink, 1990) Higher handicap golfers try to generate extra power from their shoulders rather than their trunk. (Whiteley, 1999) The same is the case for elite amateurs placing additional strain on the stabilisers of the scapula and GH joints. (Booth, 2005) Amateurs who shorten their swing to protect their lumbar spine generate extra forces in their shoulders. (Bulbulian, 2001) Mottram (1997 ) highlighted the importance of scapular setting in dynamic stability of the scapula in overhead athletes. This is supported by Kao (1995).

36 The supraspinatus and infraspinatus on the left demonstrated low activity throughout the swing. Peak activity was during take away and follow through. These muscles act as abductors and external rotators to stabilise the GH. (Kim, 2004) The subscapularis is highly active in both shoulders showing activity through most of the swing but especially at late follow through. (Pink, 1990) Lattissimus dorsi and pec major showed most activity of all the shoulder muscles. Latt dorsi acts maximally during the downswing and acceleration phases. Pec major was active later in the swing during acceleration and follow through. (Jobe, 1990) Deltoid was conspicuously inactive except for the anterior portion which was active during the follow through acting as a flexor of the arm. (Kim, 2004)

37 Kao (1995) evaluated scapular activity in elite golfers: The left trapezius, especially lower trapezius, helped to retract the scapula. It also showed greatest activity in the left side during the downswing and acceleration phases. Peak activity in the right trapezius occurred during takeaway. During downswing and acceleration the left rhomboid and lev scap were most active during scapular retraction and elevation. Right scapular protractors and scapular stabilisers were also active during downswing and acceleration phase. Serratus acts as a scapular protractor. It showed peak activity during downswing, acceleration and follow through of right arm. In the left arm, it showed low activity throughout the swing. This is why it may be at risk of fatigue.

38 Left EO is primarily responsible for initial rotation of the spine and torso during take away. Left rectus abdominus and left ES play a small role. (Hosea, 1994) Hosea showed that left EO activity is proportional to the degree of axial rotation and shoulder rotation to the right side. He showed that the R EO fires maximally on the downswing reflecting the rotational force to the L. The obliques have horizontal and vertical components. The horizontal part turns the thorax in the horizontal plane. It therefore imparts axial rotation to the lumbar spine. (Bogduk and Twomey, 1996) Contraction of the obliques engages the vertical component which causes flexion of the LS. For pure rotation to occur this flexion must be counteracted. This is done by the lumbar spine extensors, especially multifidus. (Bogduk and Twomey, 1996) ES and multifidus do not play a major role in spinal rotation (Bogduk ES and multifidus do not play a major role in spinal rotation (Bogduk and Twomey, 1996). The role of multifidus is not to produce rotation but to oppose the flexion effect of the obliques as they produce rotation.

39 For golfers with no history of LBP TA activation precedes movement. (Hodges & Richardson, 1999) For patients with a history of LBP pre emptive onset of erector spinae was observed during the golf swing. (Cole and Grimshaw, 2008). Supported by Evans (2005) who found endurance of ES in golfers with LBP was unaffected. For players with LBP EO is activated later in the swing and initiated For players with LBP, EO is activated later in the swing and initiated earlier in the downswing. (Horton, 2004)

40 1) Core Stability 2) Separation 3) Synchronisation 4) Explosiveness 5) Elasticity 6) Centre Of Gravity