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Muscle Strength & Balance Checks

A speed-strength imbalance between two opposing muscle groups may be a limiting factor in the development of speed. Muscle balance testing to compare the strength of opposing muscle groups is essential to prevent injury and guarantee the maximum speed of muscle contraction and relaxation. 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 "bodyweight". 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

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

Bench Press

This is a test for upper body strength. The need for maximum upper body strength varies between sports, and so it does not always need to be tested for. 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] is 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, then you need to devote more training attention to the muscle group of the weaker limb.


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

Related References

The following references provide additional information on this topic:

  • PAGE, P. et al. (2010) Assessment and treatment of muscle imbalance: The Janda approach. Human Kinetics
  • PAGE, P. (2011) Shoulder muscle imbalance and subacromial impingement syndrome in overhead athletes. International journal of sports physical therapy, 6 (1), p. 51
  • ZEMKOVA, E. and HAMAR, D. (2010) The effect of 6-week combined agility-balance training on neuromuscular performance in basketball players. The Journal of sports medicine and physical fitness, 50 (3), p. 262-267

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

Related Pages

The following Sports Coach pages provide additional information on this topic: