Biomechanics of the Golf Swing

By Barry H. Nolan

Between 1986 and 1995, a group of doctors and biomechanics specialists led by Frank Jobe, M.D., in affiliation with the Biomechanics Laboratory of the Centinela Hospital Medical Center, Inglewood, CA, published six papers presenting results from electromyographic research they had conducted on good golfers, i.e. all with handicaps under 5, including some professionals.

Data on twenty-four muscles between the knees and the skull were reported.  These data reveal how a body goes about hitting a golf ball, and which muscles deserve the most attention.

Only one of the reported muscles fired at 100% of its capacity.  I’ve asked over 50 golfers, of all abilities, which muscle this is, and no one has gotten the answer right.  It’s the right buttock (for a right-handed golfer).  

Even more interesting, the primary function of this muscle in the body is understood apparently only by muscle specialists.  It is technically a rotator muscle, not a flexor or extensor.  It is the reason speed skaters’ legs rotate and extend so far out to their sides.  And, for golfers, when the legs are held in place by spikes, it is the primary reason hips rotate so fast.

The third-ranked muscle (in % of capacity used) is the left quadriceps, coming in at 88%.  Your left leg gets pretty well bent at the knee during the backswing, stretching the quads.  When they fire, they drive the left hip way around and behind. 

Muscles below the waist fire before muscles above the waist.  In Five Fundamentals, Ben Hogan says: “The hips initiate the downswing.  They snap back to the left with tremendous speed.  The faster they go the better.  They cannot go too fast”.  This research shows how right on Ben’s comment was.

To accelerate the clubhead from 0 to 100 miles per hour in about 0.3 seconds, you must make major use of the big muscles in your thighs and hips.  A swing that feels as if it’s trying to hit the ball primarily with arm muscles isn’t going to win any long-drive contests.