Table 2.

The Kendall Key to Muscle Grading⁽²⁷⁾

Test	Function of muscle	Muscle grade
No movement	No contraction seen or felt	0
	Tendon becomes prominent, or feeble contraction is felt, but no visible movement	T (trace)
Supported in the horizontal plane	Movement through partial range of motion	1
	Movement through complete range of motion	2
	Holds against slight pressure in test position	3
Tests in the antigravity position	Moves through partial range of motion against gravity	3
	Gradual release from test position	4
	Holds test position (no added resistance)	5
	Holds test position against slight pressure	6
	Holds test position against slight-to-moderate pressure	7
	Holds test position against moderate pressure	8
	Holds test position against moderate-to-strong pressure	9
	Holds test position against strong pressure	10