| Soft tissue impairment is an important topic for human and animal welfare due to the vast number of occupational and sports related injuries in humans and soft tissue disorders in food animals. The underlying mechanisms in soft tissue development and repair are poorly understood. In addition, it is not clear what role exercise and immobilization play in the development and repair process of connective tissue. The test population was acquired as one-day-old chicks and raised in environmental chambers located at the Driftmier Engineering Center at the University of Georgia. Normal growth was monitored for each bird during the course of the study. Body mass, shank lengths, and shank widths were recorded every seven days beginning at one day of age. Beginning at three weeks of age, birds were placed in one of three treatment groups: control (C), paced (P), and immobilized (I). The walking protocols were conducted five days a week for 30 minutes a day (three 10-minute intervals interspersed with 10 minute rest periods) at a treadmill speed of approximately 1 mph. Beginning at three weeks of age (baseline), birds were removed at weekly intervals (3wks, 4wks, 5wks, and 6wks) from each treatment (5 birds/treatment x 3 repetitions, for a total N = 15 at each time point over the entire course of the study) based on a previously determined random selection. The response of the gastrocnemius tendon to the treatments was assessed by quasistatic failure testing. Biomechanical responses were determined based on the model of Henry et al (2000). The pacing protocol utilized in this study produced a more compliant tendon, whereas the immobilized tendons exhibited a stiffer response to the biomechanical testing. |
