http://www.jneuroengrehab.com/content/10/1/1/abstract
Abstract (provisional)
Background
Repetitive task practice is argued to drive neural plasticity following stroke. However,
current evidence reveals that hemiparetic weakness impairs the capacity to perform,
and practice, movements appropriately. Here we investigated how power training (i.e.,
high-intensity, dynamic resistance training) affects recovery of upper-extremity motor
function post-stroke. We hypothesized that power training, as a component of upper-extremity
rehabilitation, would promote greater functional gains than functional task practice
without deleterious consequences.
Method
Nineteen chronic hemiparetic individuals were studied using a crossover design. All
participants received both functional task practice (FTP) and HYBRID (combined FTP
and power training) in random order. Blinded evaluations performed at baseline, following
each intervention block and 6-months post-intervention included: Wolf Motor Function
Test (WMFT-FAS, Primary Outcome), upper-extremity Fugl-Meyer Motor Assessment, Ashworth
Scale, and Functional Independence Measure. Neuromechanical function was evaluated
using isometric and dynamic joint torques and concurrent agonist EMG. Biceps stretch
reflex responses were evaluated using passive elbow stretches ranging from 60 to 180o/s
and determining: EMG onset position threshold, burst duration, burst intensity and
passive torque at each speed.
Results
Primary outcome: Improvements in WMFT-FAS were significantly greater following HYBRID
vs. FTP (p = .049), regardless of treatment order. These functional improvements were
retained 6-months post-intervention (p = .03).
Secondary outcomes: A greater proportion of participants achieved minimally important
differences (MID) following HYBRID vs. FTP (p = .03). MIDs were retained 6-months
post-intervention. Ashworth scores were unchanged (p > .05).
Increased maximal isometric joint torque, agonist EMG and peak power were significantly
greater following HYBRID vs. FTP (p < .05) and effects were retained 6-months post-intervention
(p's < .05). EMG position threshold and burst duration were significantly reduced
at fast speeds (>=120o/s) (p's < 0.05) and passive torque was reduced post-washout
(p < .05) following HYBRID.
Conclusions
Functional and neuromechanical gains were greater following HYBRID vs. FPT. Improved
stretch reflex modulation and increased neuromuscular activation indicate potent neural
adaptations. Importantly, no deleterious consequences, including exacerbation of spasticity
or musculoskeletal complaints, were associated with HYBRID. These results contribute
to an evolving body of contemporary evidence regarding the efficacy of high-intensity
training in neurorehabilitation and the physiological mechanisms that mediate neural
recovery.
Since 6 of the 13 test items on the Wolf Test assess arm strength, significant improvement in strength after strength training could increase the Wolf score without producing any change in hand function. The Functional Independence Measure can be passed while using only the sound hand. Will researchers EVER use appropriate tests to study the efficacy of hand rehab?
ReplyDelete