Key point: A critical metric that is tracked to ensure the function of your affected leg matches the latest research on strength and force development.
LSI, or Limb Symmetry Index, is an initialism denoting the measure of performance equality between your surgical and nonsurgical limbs. Research underscores the importance of achieving not only maximum strength in both legs but also an even distribution of strength. Neglecting one leg's strength may increase the risk of injury to either limb.
To successfully transition out of this phase, it is advisable to attain at least a 70% Limb Symmetry Index. This benchmark ensures a foundational level of strength, serving as a prerequisite before advancing to more demanding and complex activities. The emphasis on achieving symmetry in strength not only promotes overall performance but also plays a crucial role in injury prevention, extending the focus beyond individual limb strength to the harmonious development of both limbs.
Calculating LSI is quite simple
Limb Symmetry Index (LSI) = (Unaffected Limb / Affected Limb) x 100
It’s the score of the affected limb divided by the unaffected limb, multiplied by 100 to produce a percentage. The score can be any unit of measurement: time, force, pounds, etc.
An example is provided in a later knowledge section for your reference.