Method for measuring golf swing efficiency
A method and apparatus for determining the efficiency of an athlete's body movement is disclosed. With particular reference to the sport of golf, the present invention relates to measuring the ground reaction forces of a golfer during a golf swing. The ground reaction forces may be resolved into a single value. At the same time, the dynamic characteristics of the golf club are also measured, including the golf club head velocity. Comparing the single value to the club head velocity allows the golfer's efficiency to be determined. The efficiency may be used for a wide variety of purposes, including fitting golf equipment, technique improvement, and fitness assessment.
1 . A method for comparing the dynamic characteristics of a golfer's body with the dynamic characteristics of the golfer's swing, comprising:
determining force components of the golfer's body by measuring forces transmitted through each of the golfer's feet during the golfer's swing;
determining a resultant force based on the force components;
determining the club head velocity of a golf club swung by the golfer; and
comparing the resultant force with the club head velocity.
2 . The method of claim 1 , wherein the force components are measured as a function of time.
3 . The method of claim 1 , wherein the determining the resultant force comprises:
correcting the force components to account for a weight component of the golfer; and
combining the corrected force components to yield the resultant force.
4 . The method of claim 1 , wherein a club head momentum is determined using the club head velocity, the method further comprising determining an efficiency ratio based on the resultant force and the club head momentum.
5 . The method of claim 4 , further comprising using the force components to determine a resultant moment, as a function of time, about a vertical axis passing through the golfer's body.
6 . The method of claim 5 , further comprising determining an angular impulse based on the resultant moment.
7 . The method of claim 6 , further comprising determining an angular momentum efficiency ratio based on the angular impulse and the club head momentum.
8 . The method of claim 1 , further comprising determining an average force and torque for at least one of the following two time durations:
a time from an initial club take away to an impact with a golf ball; and
a time from a start of a downswing until an impact with a golf ball.
9 . A method for measuring the dynamic characteristics of an athlete's performance, comprising:
determining force components transmitted through the athlete's feet;
using the force components to determine a single value representative of the athlete's performance;
determining the dynamic characteristics of a piece of athletic equipment manipulated by the athlete; and
comparing the single value representative of the athlete's body movement with the dynamic characteristics of the piece of athletic equipment.
10 . The method of claim 9 , further comprising determining the moment of the athlete's body about an axis and comparing it to the dynamic characteristics of the piece of athletic equipment.
11 . The method of claim 9 , further comprising determining the efficiency of the athlete's body movement based on the single value representative of the athlete's body movement and the dynamic characteristics of the piece of athletic equipment.
12 . The method of claim 9 , further comprising determining the dynamic characteristics of a body part of the athlete.
13 . The method of claim 9 , wherein the force components are measured as a function of time.
14 . An apparatus for correlating the dynamic characteristics of a golfer's body with the dynamic characteristics of the golfer's swing of a golf club, comprising:
a force plate selectively positioned beneath the golfer's feet;
a camera for acquiring one or more images of the golf club; and
a processor operatively connected to the force plate and the camera, wherein the processor is operable to compute a resultant force from the force plate and a golf club head velocity from the one or more images of the golf club.
15 . The apparatus of claim 14 , wherein the force plate is operable to measure force components of each of the golfer's feet.
16 . The apparatus of claim 14 , wherein the resultant force is used to determine various stages of a golf swing including backswing, downswing, and follow through.
17 . The apparatus of claim 14 , wherein the processor is operable to compare the resultant force to the club head velocity.
18 . The apparatus of claim 14 , wherein the processor is operable to determine the moment of a golfer's body about an axis.
19 . The apparatus of claim 14 , wherein the force plate comprises a first force plate and a second force plate, wherein the first force plate is selectively positioned under a first foot of the golfer, and the second force plate is selectively positioned under a second foot of the golfer.
20 . The apparatus of claim 15 , wherein the resultant force is a single value computed from the force components of each of the golfer's feet.