2012- 21st Annual NC State Undergraduate Research Symposium

Session Time : 4/10/12 12:15 PM - 4/10/12 1:30 PM

Content Area : Biomedical Engineering

Poster Appointment: , -

Student Presenters :
Arjun Puri Biomedical Engineering

Mentors and/or Co-Authors :
Paul Weinhold Biomedical Engineering

Abstract Title : Effect of Low Magnitude, High Frequency Vibrations on Rotator Cuff Tendon

Abstract :
Rotator cuff injuries are a common disability for which new therapies are needed to enhance healing and rehabilitation. Low magnitude, high frequency vibration (LMHFV) can stimulate fracture healing and may have potential to stimulate rotator cuff healing. The objective of this study was to evaluate the effect of LMHFV on the geometric and tensile properties of the intact rat rotator cuff to assess its potential for stimulating rotator cuff healing. We hypothesized that LMHFV might improve the cross-sectional area and tensile properties of the tendon. Rats were divided into 3 groups (n=12,9,9) of control, 30Hz vibration , and 60Hz vibration, respectively. Vibrated animals received 20 minutes of whole body vibrations at 0.3G peak-to-peak acceleration, per day, for five weeks. At sacrifice, the intact supraspinatus tendon of the rotator cuff was isolated and the cross-sectional area measured followed by a stress relaxation test and tensile loading to failure. Structural properties of stiffness, displacement at ultimate load, and % relaxation showed no significant differences by one-way ANOVA . The area also did not differ. The ultimate tensile load showed a trend (P=0.057) for improvement with vibration (especially 60Hz). Chi-square analysis revealed a trend (P=0.1) for a change in distribution of failure modes with treatment. Growth plate failures were the most common failure mode in the controls and tendon substance failures became more common in the vibrated groups. Further study is required to determine if the potential improved structural strength with vibration is due to changes in the growth plate or tendon substance.