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Muscle Strength & Balance Checks

A speed-strength imbalance between two opposing muscle groups may be a limiting factor in speed development. Muscle balance testing to compare opposing muscle groups' strength is essential to prevent injury and guarantee maximum muscle contraction and relaxation speed. Muscle imbalance can slow you down and result in injury.

Strength Checks

Leg press/body weight ratio

Your leg strength/body weight ratio indicates how easily you can get and keep your body moving at high speeds. This ratio is vital to speed improvements in short distances. A good ratio is 2.5 times your "body weight". If it is less than 2.5, then you should consider modifying the program to develop leg strength.

Leg strength test

The squat is considered the most functional leg strength test in predicting sprinting and jumping ability. Good 1RM (one rep max) scores are:

  • Male athletes 2 × "Body Weight"
  • Female athletes 1.5 × "Body Weight"

Hamstring/Quadriceps strength

Record the 1RM for the leg curl and leg extension exercises for each leg. Divide your leg curl score by the leg curl extension to find each leg's ratio. For each leg, the curl score should be at least 80% of your extension score. If the score is less than 80%, you must devote more training to the hamstrings. The ratio should be at least 75% to reduce the chance of injury.

Bench Press

This is a test for upper body strength. The need for maximum upper body strength varies between sports, so it does not always need to be tested . Good 1RM scores are:

  • Male athletes 1.25 × "Body Weight"
  • Female athletes 0.8 × "Body Weight"

Balance checks

For each of the following exercises, the right and left limb 1RM scores should not differ by more than 10%.

  • Hamstrings (leg extension)
  • Quadriceps (leg curl)
  • Arm Curl
  • One arm military press
  • Single leg press

The following table (Dintiman 1998)[1] shows reported values for joint agonist-antagonist muscle ratios at slow isokinetic speeds.

Joint Movement Ratio
Ankle Plantar flexion/dorsiflexion 3:1
Ankle Inversion/eversion 1:1
Leg Extension/flexion 3:2
Hip Extension/flexion 1:1
Shoulder Flexion/extension 2:3
Elbow Flexion/extension 1:1
Lumbar Flexion/extension 1:1

Where there is an imbalance, you must devote more training to the weaker limb's muscle group.


  1. DINTIMAN, G. et al. (1998) Sports Speed. Leeds: Human Kinetics. p. 34

Page Reference

If you quote information from this page in your work, then the reference for this page is:

  • MACKENZIE, B. (2000) Muscle Strength and Balance Checks [WWW] Available from: [Accessed