In this chapter, "hips" refer primarily to the hip, knee and ankle joints. Anatomically, hips, knees and ankles are separate entities, but in golf, they work as a system with the ultimate goal of moving (primarily rotating) the spinal column that sits above it.
Think of the hips in terms of a bone structure. The upper part of this structure provides the base for the spinal column. The lower part of the structure provides the ball and socket joint for the upper leg (femur).
The hip joints are inside the periphery of the bone structure. That is because the upper leg (femur) is L shaped. The upper leg (femur) has a long straight vertical component leading to a ball-like structure called the trochanter. The upper leg then has a horizontal component with a ball at the end. The ball fits into a socket within the bone structure.
Because the joint between the bone structure and the femur is a ball and socket joint, each femur can move in a variety of directions relative to the bone structure: toward the front, toward the back, away from the body centre, toward the body centre and a variety of positions in between. It can also rotate within the hip joint. You can get a sense of this rotation by sitting in a chair, and turning the knee clockwise and counter-clockwise.
Muscles attach to various points on the femur and the bone structure. Their contraction and relaxation causes these movements.
The muscles around the hip joint control the tilt of the bone structure relative to the upper leg. For example, contracting the muscles around the hip joint to bring the upper leg forward effectively tilts the bone structure forward. This in turn tilts the spinal column forward.
Apart from the tilting of the bone structure, the bone structure goes where the hip joints take it. If the hip joints tilt so that one is higher than the other, the bone structure tilts too. If the hip joints move to the left or right, the bone structure and spinal column follow and move to the left or right. If the hip joints rotate, the bone structure and spinal column rotate.
The base of the spine comes out of the bone structure. It goes where the bone structure takes it. Moving the bone structure requires movement of the hip joints. Movement of the hip joints depends on the workings of joints below it, namely the knee and the ankle joints.
The knee joint is a hinge joint between the upper leg (femur) and the two bones in the lower leg bones (tibia and fibula). In the absence of gravity, when muscles attached to the front of the lower and upper leg bones (quadriceps) contract, they cause a bent leg to straighten. When muscles attached to the back of the lower and upper leg bones contract, they cause a straight leg to bend behind.
When gravity is involved (for example in bending the knee from a standing position), bending the knee will come from relaxing the contraction of the quadriceps.
The knee joint does not allow the two bones in the lower leg to rotate relative to the upper leg. To get a sense of this, sit in a chair, straighten the knee out in front, hold your upper leg to immobilize it, and try turning your lower leg (not your ankle) left or right. You will not find much movement.
The ankle is where the foot and the two bones in the lower leg meet. It includes three joints that collectively allow the foot to move in a variety of directions. One can:
Test all these movements by sitting in a chair, moving the foot in the aforementioned directions, and sensing which muscles are involved.
Observe the movement of the toe relative to the heel. If you start with your foot perpendicular to the ground, you should be able to rotate your foot inward toward the body centre (pronation) about 10 degrees, and rotate your foot outward (supination) about 60 degrees.
The "hips" are important in the golf swing. One way to get a sense of their importance is to immobilize them by sitting in a chair, and then to try to hit golf balls. Alternatively, place your butt against the back of a chair, and hit golf balls while keeping your butt in contact with the chair. You should be able to feel the importance of the "hips" by noting the loss of power when they are immobilized during the golf swing.
The diagram provides a top down caricature of the bone structure. The spinal column is located in the middle and at the back. The two hips joints are toward but slightly inside both ends of the bone structure.
There are two ways golfers can use this bone structure to create power in the golf swing.
On moving the bone structure laterally toward the target, we make these observations:
On rotating the bone structure, we make these observations:
To get a sense of Pure Rotation, stand erect with spine vertical to the ground with your feet directly below your hip joints, lock your knees, keep both feet flat on the floor, put your weight on the instep of each foot (by eversion at both ankles i.e. rolling both ankles outward), and then turn your hips clockwise and counter-clockwise while keeping your weight on the step of both feet. If you start with your hips in a neutral initial position, you will be able to turn about 45 degrees in each direction.
The 45 degree rotation in both directions occurs even though one can only rotate each foot inward by about 10 degrees and outward by about 60 degrees. The explanation for the seemingly contradictory numbers is a combination of the effects of plantar flexion of one ankle and dorsi flexion of the other, and vice versa, as well as rotation of the upper leg in the hip socket.
A key to the movement is keeping the head and spine in the same place. Performing the movement in front of a mirror allows you to monitor how you are doing. If you find your head and spine have moved, chances are you are allowing one or both ankles to roll. Inversion of one ankle and eversion of the other, taken alone, will move the bone structure laterally.
In the golf swing, the hips normally lead the swing, so that at impact, the hips have moved beyond the start position. Consequently, the downswing rotation of the "hips" is likely to be about 10 degrees more than the backswing rotation.
Consider what happens to your weight in Pure Rotation when done properly without eversion or inversion of the ankles. Your centre of gravity and the location of your weight will generally sit in the middle of your stance, not toward your heels or toes, or toward one foot or another. You can check the purity of your rotation by doing the Pure Rotation movement on a balance aid such as a BOSU ball or balance board or a mirror.
Try this exercise again, but this time, try to discern which muscles cause the hip rotation. Do the exercise clockwise and counter-clockwise until you begin to fatigue the muscles. You will discover that it is the muscles around your ankles that are causing the rotation.
Let us look more closely at what is happening in Pure Rotation. The hip joints rotate in a circle around a centre point between them. This point is close to the base of the spine. To rotate in a golf swing that starts at the neutral address position, the lead hip joint would move toward the ball and away from the target on the backswing, while the trailing hip joint would move toward the target and away from the ball on the back swing. In the downswing, the hip joints would return to the neutral start position, after which the lead hip joint would move away from the ball and target, while the trailing hip joint would move toward the ball and target. The table below summarizes how ankle and knee joint movements in one leg will move the related hip joint.
|Ankle and Knee Joint Movement
|Related Hip Joint Movement In the Golf Swing
|Moving the foot up toward to the shin (dorsi flexion of the ankle)
|Moves the hip joint toward the ball.
|Moving the foot down away from the head (plantar flexion of the ankle)
|Moves the hip joint away from the ball
|Rotating the toe relative to the heel inward toward the centre of the body (pronation of the ankle)
|Rotates the leg in the hip joint inward
|Rotating the toe relative to the heel outward away from the centre of the body (supination of the ankle)
|Rotates the leg in the hip joint outward
|Turning the entire sole of the foot inward toward the centre of the body (inversion of the ankle)
|Moves the hip joint laterally away from the outside of the foot
|Turning the entire sole of the foot outward away from the centre of the body (eversion of the ankle)
|Moves the hip joint laterally toward the outside of the foot
|Increasing the bend of one leg at the knee (without changing the angle between the foot and the lower leg)
|Moves the hip joint away from the ball and decreases the elevation of the hip joint.
|Decreasing the bend of the leg at the knee (without changing the angle between the foot and the lower leg)
|Moves the hip joint toward the ball and increases the elevation of the hip joint.
Here is how the muscles work through the three phases of the golf swing in Pure Rotation.
|Golf Swing Phase
|Start Position to Top of Backswing
|Dorsi flexion and pronation of the ankle, causing the lead hip to move toward the ball and away from the target.
|Plantar flexion and supination of the ankle, causing the trailing hip to move away from the ball and toward the target
|Top of Backswing Back to Start Position
|Plantar flexion and supination of the ankle to the neutral position, causing the lead hip to move away from the ball and toward the target
|Dorsi flexion and pronation of the ankle to the neutral position, causing the trailing hip to move toward the ball and away from the target
|Start Position to Impact
|Plantar flexion and supination of the ankle, causing the lead hip to move away from the ball and away from the target.
|Dorsi flexion and pronation, causing the lead hip to move toward the ball and toward the target.
For knees to contribute Pure Rotation, the lead knee would need to straighten from the start position to the top of the backswing to move the lead hip forward toward the ball, and bend from impact to the finish to move the lead hip away from the ball. The trailing knee would need to bend in the backswing to move the trailing hip away from the ball, and straighten from impact to the finish to move the lead hip toward the ball.
Although use of the knees in this way is a theoretical possibility, they are not part of an effective golf swing for several reasons. First, successful golfers do not swing this way. In fact, if they change the bend in their knees at all, they do exactly the opposite. Second, knee bending is another movement and every movement carries the risk of error. Third, the combination increasing and decreasing the bend in the knees throughout the swing will lead to different elevations in the bone structure, and will ultimately cause the spine angle to change. Fourth, to get a Pure Rotation, there needs to be a balance between the amount of movement toward and away from the ball, and toward and away from the target. One can get adequate balance without changing the bend in the knees, with the result that knee bends can destabilize the swing.
The diagram illustrates Pure Rotation. The balls at the end of the lines indicate the hip joint positions. The green dotted line denotes the start position. The black dotted line shows the rotation for a right-handed golfer on the backswing. The red line indicates the hip joint position at impact (i.e. slightly beyond the start position). Both hip joints are moving around the circumference of a circle (more or less).
The hip joints are typically about 32 inches from the ankle (ground). A change of a few degrees in the angle between the ankle and leg will end up moving one hip joint several inches. The two hip joints are about 7 inches apart. Moving both the lead and trailing hip joints a few inches around a circle when they are relatively close can translate into considerable rotation at the base of the spine.
If you want to experiment with Pure Rotation, here are some ideas:
Push and Clear works. The "push" movement lengthens the trailing leg during the downswing. The "push" comes from pointing the toe and straightening the leg at the knee. The "clear" movement gets the lead hip joint out of the way.
The diagram illustrates what happens with the trailing leg during the "push". The solid black line depicts the front view at the top of the back swing for a right-hand player. The diamond at the bottom of the line depicts the foot, while the ball at the top depicts the trailing hip joint. The line is in fact the line from the foot to the hip joint. Because the femur has a right angle bend at the top, the line does not depict the actual leg. Note that the line is slanted, because in normal circumstances the foot would be placed at shoulder width and the hip joint would lie inside the shoulder width. The dashed red line shows what happens at impact to the line when the trailing leg is lengthened and the hip joint elevation remains constant. The trailing hip joint moves in the direction of the target.
You can figure out how much you can lengthen your leg by standing next to a wall, with knees bent as in a normal set up. Measure the elevation of the hip joint on the wall. As we shall see, this is the effective length of your leg at set up and at the top of the back swing, because we suggest the leg should not move in the back swing. Now, straighten the bend in the knee and stand on your toe. Measure the elevation of the hip joint on the wall. Compare the two measurements, to determine how much you lengthened your leg.
To get an accurate determination of the movement of the hip joint in the downswing, you would have to apply some geometry to account for the angles involved, and you would have to take into account how much leg lengthening occurs up to impact. The geometry is addressed in Chapter 10 and 11. Regardless of the specific measurements, our purpose here is to show where the power comes into the golf swing.
As indicated above, lengthening the trailing leg involves straightening the bend at the knee using the quadriceps, combined with moving the toe away from one's head (plantar flexion). Lengthening the leg by itself is not sufficient to create power in the swing. The leg lengthening has to be in the direction of the target. This requires:
The diagram illustrates the top down view of the Push and Clear downswing. The balls at the end of the lines indicate the hip joint positions. The dotted horizontal green line denotes the start position. The black line shows the rotation for a right-handed golfer at the top of the back swing. The solid red line indicates the hip joint position at impact (i.e. slightly beyond the start position of the downswing.
Note that the black ball is on top of, and covering, what would be the green ball, illustrating the point that the trailing hip joint has not moved from the original position during the back swing. In addition, the lead hip has moved toward the ball and away the target. At impact, the red ball denoting the trailing hip has moved directly toward the target, while the lead hip has moved away from the ball and slightly toward the target, all relative to the start position.
The Push and Clear downswing involves a "push" off the trailing leg, as well as a "clear" by the leading leg. The "clear" is as important as the push, since it allows the "push" to produce some rotation of the bone structure. The "clear" movement in the leading leg is the same movement that occurs with Pure Rotation.
The bone structure and base of the spine move laterally toward the target and away from the ball. The amount of movement is small.
If you want to experiment with the Push and Clear movement, here are some ideas. Keep in mind that leaning forward at the hip joints affects the Push and Clear, so you get the best sense of the Push and Clear movement by standing vertically to the extent possible.
More knee bend at set up and at the top of the back swing translates into greater lengthening of the trailing leg on the downswing, and ultimately more power. Conversely, relatively straight legs defeat the purpose of the Push and Clear. If one starts with relatively bent legs, the bend in the trailing leg disappears in the "push" movement, but the bend in the leading leg should be maintained in the "clear" movement until after impact. Straightening a bent lead leg on the downswing has the effect of moving the lead hip joint toward the ball, which neutralizes the rotation.
The direction of the "push" during the downswing matters. Turning the trailing foot outward (and the trailing leg inward) during the downswing plays a key role in determining the direction of the "push". A "push" toward the target commits energy to the direction of the hit.
An essential element of the Push and Clear is that the trailing hip joint does not move in the back swing. To clarify, the hip joint is inside the perimeter of the bone structure; it should not move. However, the outside points of the bone structure will rotate, since the bone structure itself is rotating. When you look at videos of yourself or others, or watch other players, or look at your swing in a mirror, look at the upper trailing leg, not at the belt position of the side of the trailing hip. A stationary trailing hip joint is indicated by a stationary upper leg.
The belt position on the side of the trailing leg should move, because the bone structure is rotating around the stationary trailing hip joint. As we saw in the section on hip anatomy, the upper leg can rotate to some degree within ball and socket joint in the hip.
The Push and Clear feels like a powerful move, because the leg extension uses the quadriceps to straighten the leg at the knee, and the ankle muscles. These are among the strongest muscles in the body.
There is a theory in golf that one should "load" up on the trailing leg in the back swing (i.e. shift one's weight to the back foot), and then push forward in a power move on the downswing. It does not make sense to move one's weight backward in the back swing, and then forward to the initial position and beyond in the downswing. There is extra, unproductive movement in this swing. It makes more sense to start with one's weight on the back foot at address and move it forward with "push". This should work, provided the initial position is such that the trailing leg is in a position to "push" forward. The top players tend not to swing this way. Most start the swing at address with their weight relatively evenly distributed between lead and trailing feet.
Proper foot position at address can facilitate the Push and Clear. The trailing foot should be at least perpendicular to the line of flight at address, to ensure the trailing leg is in a position to "push". A trailing foot with the toe pointed slightly toward the target can facilitate the "push" on the downswing. It can also help keep the trailing hip joint stationary during the back swing, since it restricts the ability its ability to move. A lead foot perpendicular to the line of flight can facilitate the "clear", since a plantar flexion of the foot (i.e. move the toe away from the head) can implement the "clear". The diagram below illustrates the position.
As a reminder of the technical differences between Pure Rotation and Push and Clear, the previous diagrams are repeated below. The balls indicate the hip joints. The green structure indicates the start position, the black the position at the top of the back swing, and the red the impact position.
Which to pursue? The story is not finished. Chapter 9 deals with the spinal tilt, which is intimately related to how one uses the hips and lower body. Chapters 10 to 13 deal with the physics of golf, and they too have something to say on the question. However, the conclusion is that you should try both approaches, and see which works best for you.
Your assessment should take into account the potential distance effect (from the physics of golf), spinal health (related to the spinal tilt), your ability to achieve the potential distance consistently, and your ability to hit the ball online.