Hip mobility for golf: what the downswing uses

The swing spends the lead hip and saves the trail one

34.8° vs 8.9°Lead-hip internal rotation coming down, against trail-hip internal rotation going back

Gulgin, Armstrong and Gribble filmed fifteen female golfers, handicap 5.2 on average, with eight cameras sampling at 120 Hz, ten driver swings each. The aim was to count degrees of hip rotation during a real swing rather than on a treatment table. The count comes out lopsided.

Going back, the trail hip rotated inward 8.9 degrees while the lead hip rotated outward 29.7. Coming down the pattern reversed and grew: 34.8 degrees of internal rotation from the lead hip against 14.9 degrees of external rotation from the trail one. Both gaps held at p < 0.001.

Set those against what each hip had available and the asymmetry sharpens. The trail hip spent between a fifth and under a third of its internal rotation. The lead hip spent most of what it owned. One hip works near its limit twice a swing, and the other is barely asked.

Standing up straight hides 13 degrees

13 to 14 degreesInternal rotation gained by measuring in address posture rather than standing upright

The same study measured available rotation three ways, and the answer moved each time. Upright, with the feet under the hip joints, the lead hip offered 26.5 degrees of internal rotation. Widening to a driver stance changed almost nothing, at 27.2. Adding the golfers' own address posture, an average of 38.7 degrees of hip flexion and 24.7 of knee flexion, took it to 41.1.

Internal rotation gained 13 to 14 degrees from that change of position, and stance width alone did none of it; the authors credit hip flexion with slackening the capsule and the internal rotators. So the 34.8 degrees the downswing used is 84.6 percent of the address-posture figure and 131.3 percent of the upright one. A hip tested standing tall reads short when the swing has no argument with it.

The back-pain link, and what pooling did to it

−1.3 to 3.8Pooled 95% confidence interval, lead-hip internal rotation against low back pain

Vad and colleagues measured 42 consecutive professional male golfers for the American Journal of Sports Medicine. Thirty-three percent had a history of low back pain that had affected their play that year. Three measures tracked with it at p < .05: reduced lead hip internal rotation, FABERE's distance and lumbar extension. Trail hip range of motion tracked with nothing, and most advice about lead hip mobility traces to this.

It did not survive pooling. Smith, Hawkins, Grant-Beuttler, Beuttler and Lee gathered four such studies for Sports Health, and for lead hip internal rotation the standardised mean difference came out at 1.25, confidence interval −1.3 to 3.8. That straddles zero: the four disagree. Two did find greater side-to-side asymmetry among golfers in pain, the shortfall on the lead side, but those numbers would not pool. The spine's side of it belongs to the lower back guide.

The screens that caught the fault were not hip screens

The Titleist Performance Institute states the mechanism plainly. If the pelvis cannot rotate around the lead hip because of joint or muscular restriction, forward and lateral movement will dominate the pattern instead. Forward is early extension, which has its own guide. Lateral is sway and slide, which has another.

Gulgin came back with Schulte and Crawley to test that. Thirty-six golfers took twelve TPI level 1 screens, then hit four 5-irons on video scored for fourteen faults. Three associations reached significance: the toe touch with early hip extension at p = 0.015, the bridge with early hip extension at p = 0.050 and loss of posture at p = 0.028. Failing the overhead deep squat or a single-leg balance made early hip extension, loss of posture or a slide two to three times more likely.

Not one of those screens measures hip rotation. Thirty-six golfers is a small sample and a result that missed significance is not a disproof, but the screens that did predict the fault point at hamstring length, gluteal strength and the squat pattern rather than at a stiff joint.

Screening your own, and what rotation is worth

The overhead deep squat is the one to run first: no goniometer, and it is the screen with an odds ratio behind it. Hold a club at shoulder width, press it overhead in line with your head, and squat as far as you can. TPI's pass wants the thigh below horizontal, knees over the feet, feet still pointing forward, and the torso parallel with the shin or more upright. Heels lifting ends it.

For rotation itself, the plane matters more than the amount. McHugh and colleagues ran fourteen flexibility tests on twenty-five male golfers, thirteen off 5 or better against twelve between 10 and 20. The better group was more flexible only in the transverse plane, the hips at p < 0.0001; in the sagittal and frontal planes the two were indistinguishable. Transverse-plane hip flexibility accounted for 48 percent of the variability in ball speed.

None of it shows in a video. Hip rotation turns the thigh about its own long axis, which points mostly toward and away from a single lens, so a camera infers the motion rather than seeing it. Pebble Swing reads joint angles and the backswing-to-downswing tempo ratio out of the frames, and hip rotation is not among them.