Assessing Elastic Leg Strength with Sprint Bound Index Test
- 400m track – 30m marked section on the straight
- Stop watch
- Two assistants.
- Begin with one foot on the start line and place the other foot 2 to 3 feet behind you
- Place both of your helpers at the finish line – one to count the number of foot contacts and the other to time your sprint-bound effort over the 30m distance
- On your own command, sprint-bound down the track for the entire 30m distance
- The timer should start the watch when the foot on the start line breaks contact with the ground and then stop the watch when your torso crosses the finish line
- The time is recorded by rounding up to the nearest tenth of a second
- Your second helper is responsible for counting the number of bounds it takes you to reach the finish line
- The number of bounds should be rounded down to the nearest half-bound
- Perform three trials, with 3 to 5 minutes between each trial
- Record the results of all three trials.
Calculate the ‘sprint-bounding index’ for each trial using the following formula:
- Sprint-bound index (SBI) = (no. of bounds) x (time for 30m)
You have taken 15.5 bounds to cover the 30m, in a time of 4.5 seconds.
- SBI = 15.5×4.5 = 69.75.
This test is suitable for active individuals but not for those where the test would be contraindicated.
Reliability would depend upon how strict the test is conducted and the individual’s level of motivation to perform the test.
There are no published tables to relate results to potential performance in competition.