Martin E Héroux

Learn More
In the present report, we investigated changes in corticomotor excitability associated with unilateral knee dysfunction secondary to anterior cruciate ligament (ACL) injury. Ten participants, each with a previous history of unilateral ACL injury (median time post-injury 22 months) and eight healthy controls underwent transcranial magnetic stimulation (TMS)(More)
OBJECTIVES Determine the effect of inertial loading on the strength of motor unit entrainment and the synergistic/competitive interaction between central and mechanical reflex tremor components in subjects with essential tremor (ET). METHODS Twenty-three subjects with ET and 22 controls held their hand in an outstretched position while supporting(More)
In a standing position, the vertical projection of the center of mass passes in front of the ankle, which requires active plantar-flexor torque from the triceps surae to maintain balance. We recorded motor unit (MU) activity in the medial (MG) and lateral (LG) gastrocnemius muscle and the soleus (SOL) in standing balance and voluntary isometric contractions(More)
OBJECTIVE To evaluate functional mobility and postural control in participants with essential tremor (ET). DESIGN Cross-sectional cohort study. SETTING Motor performance research laboratory. PARTICIPANTS Sixteen participants with ET including head tremor (age, 59.4+/-12.0 y), 14 participants with ET and no head tremor (age, 57.1+/-15.9 y), and 28(More)
The mechanisms by which skeletal muscles lengthen and shorten are potentially complex. When the relaxed human gastrocnemius muscle is at its shortest in vivo lengths it falls slack (i.e. it does not exert any passive tension). It has been hypothesised that when the muscle is passively lengthened, slack is progressively taken up, first in some muscle(More)
OBJECTIVE To determine the extent of disability in subjects with essential tremor (ET) using time-based, standardized measures of upper-extremity function. DESIGN Descriptive case series. SETTING Motor performance research laboratory. PARTICIPANTS Thirty subjects with ET (mean age, 58.3+/-13.7 y) and 28 healthy controls (mean age, 58.4+/-12.4 y). (More)
OBJECTIVES Determine the effect of concentric and eccentric movement and contraction intensity on the strength of rhythmic muscle activity in individuals with essential tremor (ET). METHODS 21 ET subjects and 22 healthy controls produced wrist flexion-extension movements while supporting sub-maximal loads (no-load, 5%, 15% and 25% 1-repetition maximum).(More)
Essential tremor is the most common movement disorder, typically characterized by the presence of both postural and kinetic tremor of the hand. In recent studies, we described the effects of altering force and load conditions on tremor amplitude and power in people with essential tremor. In the same participants, we also measured tremor-related functional(More)
OBJECTIVES Quantify the effect of increasing contraction intensity on the amplitude of force fluctuations and neuromuscular and force tremor spectral power. METHODS Twenty-one subjects with essential tremor (ET) and 22 healthy controls applied isometric wrist extension contractions. Various sub-maximal contraction intensities were evaluated (5%-, 10%-,(More)