Effect of Vibration Exercise on Upper Limb Strength, Function, and Pain

The primary purpose of this study is to explore the benefits of vibration dumbbell resistance training over standard dumbbell resistance training for improving upper limb strength, function and pain among manual wheelchair users with paraplegia.

Objectives: The primary purpose of this study is to explore the benefits of vibration dumbbell resistance training over standard dumbbell resistance training for improving upper limb strength, function and pain among manual wheelchair users with paraplegia. Experimental Design: Design: Randomized Control Trial Methods: Twenty subjects with paraplegia will be recruited and randomized into two groups, a vibration dumbbell training (V-DT) group and a standard dumbbell training group (S-DT). Both groups will participate in a supervised 12-week (3 sessions per week) dumbbell (free-weight) strength training program consisting of nine exercises specifically designed to improve upper limb muscle function to support propulsion and transfer activities and protect the shoulders from developing pain. For each of the nine exercises the vibration group will hold a high-frequency (40 Hz) vibrating dumbbell in a static arm posture (isometric training) while the control group will move a non-vibrating dumbbell through the full range of motion for a given exercise (isotonic training). Both groups will follow a standardized protocol for assessing and progressing the amount of weight that is added to the dumbbell to achieve optimal training effects. All participants will participate in laboratory testing for various outcome measures at baseline, 6 weeks and 12 weeks .

Study participants who are randomized into the vibration exercise group will complete an in-home exercise program using a vibrating dumbbell.

Study participants who are randomized into the control exercise group will complete an in-home exercise program using standard dumbbells.

Supervised training sessions will occur optimally, 3 times per week for a total of 12 consecutive weeks. The sessions will involve nine exercises specifically designed to improve upper limb muscle function. The beginning training intensity for each participant will be based on their one rep max for each exercise, which is determined during baseline laboratory testing in accordance with standard procedures. Training intensity will be adjusted progressively, first by increasing the frequency of the vibration (max. 40 Hz) then by the addition of more weight, based on weekly assessments and consultation with the senior investigators.

Supervised training sessions will occur optimally, 3 times per week for a total of 12 consecutive weeks. The sessions will involve nine exercises specifically designed to improve upper limb muscle function. The beginning training intensity for each participant will be based on their one rep max for each exercise, which is determined during baseline laboratory testing in accordance with standard procedures. Training intensity will be adjusted progressively by the addition of more weight, based on weekly assessments and consultation with the senior investigators. To obtain as much data as possible on resistance training with vibration within study timeline, a modification was recently approved by the Institutional Review Board (IRB) to cease enrolling subjects into standard dumbbell training.

Measurement of peak torque (Nm/kg) for Shoulder Adduction. Measurement was done using the Biodex System.

Score generated by the Numerical Rating Scale for shoulder pain. Participants self report upper extremity pain over the last 24 hours with scores on a 0 to 10 scale. Higher scores represent higher levels of pain.

Score generated by the Short Form 36 walk-wheel. Participants self report on health questions within 8 domains each of which are scored from 0 to 100. The scores from each of the subscales are then averaged together to obtain an overall total score. A score of 0 represents the worst possible health state and a score of 100 represents the best possible health state.

Score generated by the Wheelchair Users Shoulder Pain Index. Participants self report shoulder pain over the past week while performing activities of daily living. Scores range from 1 to 150 where higher scores represent higher levels of pain.

Change in peak speed (m/s) measured on a 3 degree incline. Measurement will be done using the SmartWheel.

Change in peak force (N) during the 250 foot level propulsion task. Measurement was done using the SmartWheel.

Change in mechanical effective force during 250 foot level propulsion task (no unit) Measurement will be done using the SmartWheel.

Measurement of relative transfer range. Measured as the change in relative uphill (maximum) transfer height (inches).

Inclusion Criteria: have a neurological impairment secondary to spinal cord injury (SCI) or disease at T2 or lower greater than 6 months post injury use a manual wheelchair as primary means of mobility (at least 30 hrs. per week) 18 to 65 years of age provide signed medical release by primary care physician to engage in a high-intensity resistance training exercise program live within 60 minutes driving time (1 hour) from the research center able to perform a transfer independently to and from a wheelchair have normal range of motion in the upper limbs. Exclusion Criteria: history of fractures or dislocations in the shoulder, elbow and wrist from which the subject has not fully recovered or joint replacement of any of the joints in the upper extremities upper limb pain that interferes with the ability to propel or transfer recent hospitalization for any reason (within the past three months) pregnant women history of coronary artery disease, coronary bypass surgery or other cardio-respiratory events