2012 Annual Conference

DUGAN, KRITIN

TEXAS STATE UNIVERSITY-SAN MARCOS

Background:           Although the incidence of stroke is the number one reason for adult disability, rehabilitation  strategies  for recovery of the upper extremity continue to challenge rehabilitation specialists. (1)  In addition, the benefits of MENS for pain and tissue healing are well known however little is known about its use for hemiparetic muscle response to therapeutic exercise.(2, 3)  The aim of this study was to investigate voluntary upper limb control in chronic stroke survivors in response to standardized MENS combined with moderate intensity therapeutic exercise.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   for Study Design:          Single site, randomized controlled trial, pilot investigation  

Participants:          18 chronic stroke survivors (M/F = 12 / 6) from the surrounding San Marcos community, were recruited, average age 59.68 +/- 18.67 years and randomly assigned to two treatment groups MENS (w/MENS, n= 10), and CONTROL (w/o MENS, n = 8) in a university outpatient physical therapy clinic.  Average chronicity of impairment was 3.75 +/- 2.23 years for 9 Right and 9 Left side involvement.

Methods:             Both groups participated in therapeutic exercise to promote “forced-use” of the impaired limb with mass practice including strength and endurance training, total body reciprocal training and robot-assisted limb activities 60 – 90 minutes, twice a week for 12 weeks.  Patients in the MENS group wore portable electrotherapy units (QuadStar II) during clinic sessions set at sub-threshold levels (without muscle contraction). In addition, patients used the units during a standardized Home Exercise Program which was prescribed for both treatment groups. All patients were assessed three times at Baseline, 6-weeks and 12-weeks.

Patient Outcomes:           Primary disability measures included the Chedoke McMaster Arm & Hand Index (CMAHI), Action Research Arm Test (ARAT), Motor Activity Log-28 (MAL), Modified Ashworth Scale (MAS), and the Stroke Impact Scale (SIS).  Performance measures included the Box & Blocks Test (BBT), dynamometer grip strength (GRIP) and surface electromyographic (sEMG) activity in both upper extremities during a “Push Task” which simulated the sit-to-stand transfer.  EMG signals were processed using the FlexComp Infiniti digital encoder software (Thought Technology, Ltd Montreal, Canada) for outcomes: Mean muscle activity (MMA), and relative intra- (MS_RATIO) and inter-limb (SIDE_SYM) muscle activity for three muscles, Anterior Deltoid (AD), Triceps (TR) and Flexor Digitorum Superficialis (FDS).

Data Analysis:    Statistical data analysis included descriptive statistics and repeated measures MANOVA using a Group x Time factor analysis.  Due to small sample sizes, Games-Howell Post Hoc analysis with a Bonferroni correction was used at an alpha level of 0.05. 

Results:                Preliminary results indicate a significant difference in group CMAHI (p = 0.009), BBT (p < 0.05) and SIDE_SYM (p < 0.05), values at 12-weeks. There was a significant Group x Time interaction effect for MAL (p = 0.040) and SIS scores (p= 0.027).

Conclusions:     Preliminary study results indicate that standardized MENS treatment in combination with moderate intensity therapeutic exercise is tolerated well by chronic stroke survivors and can significantly increase upper limb muscle response in arms to transfer sit to stand.

Implications for stroke rehabilitation will be discussed.

 References:

1. Schwamm L et al. (2010). “A Presidential Advisory From the American Heart Association/American Stroke Association/American Stroke Association to Reduce Death and Disability Due to Stroke: A Presidential Advisory From the American Heart Association/American Stroke Association”. Stroke. 2010;41:1051-1065;
2. Poltawski, L. and T. Watson (2009). "Bioelectricity and microcurrent therapy for tissue healing - a narrative review." Physical Therapy Reviews 14(2): 104-114.
3. Mäenpää H, Jaakkola R, Sandström M, Von Wendt L. (2004) Does microcurrent stimulation increase the range of movement of ankle dorsiflexion in children with cerebral palsy? Disabil Rehabil. Jun 3;26(11):669-77