Measuring strength

Warning

Leg Press/Sit to Stand

Test either Leg Press (if machine is available) or single leg sit to stand.

Leg Press

Measuring 1RM in post operative patients/rehabilitation may not be appropriate; either 5RM/10RM may be more suitable.  LSI can be calculated using these parameters.

If Leg Press is unavailable, then a max rep single leg sit to stand can be used.  This is demonstrated in the following video:

Mick Hughes Single Leg Sit To Stand (video link)

Single Leg Bridge

Patient in Supine bridge position, knees at 90˚. Ask patient to lift one foot from the floor and proceed to bridge 20 repetitions, or until fatigue or unable to complete a full repetition.

Repeat on opposite leg.  Use the numbers for each leg to calculate LSI.

Pure Physio Single Leg Bridge Test (video link)

Calculation of Limb Symmetry Index (LSI)

LSI (%) = Injured Limb Score ÷ Uninjured Limb Score x 100

Calculation of Relative Strength Index (RSI)

RSI (%) = weight pushed (Kg) ÷ bodyweight (Kg) x 100

Editorial Information

Last reviewed: 22/07/2024

Next review date: 22/07/2025

Approved By: MSK Physiotherapy Extended Management Team

Reviewer name(s): Louise Ross, Alison Baird, Karen Glass.