Table 3.

Muscles exhibiting significantly modulated stretch reflexes at matched levels of background muscle activity

	Perturbation Direction
	Primary Axis		Secondary Axis
Muscle	Anterior	Posterior	Medial	Lateral
Experiment 2
BRD
BI				++O
TRILO	−A		++O	−A
TRILAT			++O	−A
AD	−A			+O
MD	+O	+O	++O
PD			++O
PECTCLAV				++O
Experiment 3
BRD	++A
BI
TRILO			++O
TRILAT		+A (0.052)	+O
AD	−−A	+A
MD
PD	+A	−A	+O
PECTCLAV	−−A	++A	−O	++O

Number in parentheses indicates P value. BRD, brachioradalis; BI, biceps brachii; TRI_LO, long head of triceps brachii; TRI_LAT, lateral head of tricep brachii; AD, MD, and PD, anterior, medial, and posterior deltoid, respectively; PECT_CLAV, clavicular head of pectoralis major.