Metrics details. We examined the effectiveness of a manual therapy consisting of forearm skin rolling, muscle mobilization, and upper extremity traction as a preventive treatment for rats performing an intensive lever-pulling task.
We hypothesized that this treatment would reduce task-induced neuromuscular and tendon inflammation, fibrosis, and sensorimotor declines. Results were compared to similarly treated control rats C-Tx and C-Ac. TASK-Ac rats had more extraneural fibrosis in median nerves, pro-collagen type I levels and immunoexpression in flexor digitorum muscles, and fibrogenic changes in flexor digitorum epitendons, than TASK-Tx rats which showed comparable responses as control groups.
TASK-Ac rats showed cold temperature, lower reflexive grip strength, and task avoidance, responses not seen in TASK-Tx rats which showed comparable responses as the control groups. Manual therapy of forelimbs involved in performing the reaching and grasping task prevented the development of inflammatory and fibrogenic changes in forearm nerves, muscle, and tendons, and sensorimotor declines. Peer Review reports. Musculoskeletal disorders secondary to occupational overuse are highly prevalent in many professions [ 1 , 2 , 3 ].
These injuries and disorders have profound effects on the neuromuscular system which includes nerves, muscles, and tendons [ 4 ]. We have a rat model of occupational overuse injury, in which rats voluntarily reach and pull on a lever bar at target reach rates and force levels for a food reward [ 7 ]. In this model, operant reach rates and force levels were determined from studies on risk exposure to humans involved in occupational jobs [ 6 , 8 ]. Prolonged performance of a high repetition high force lever-pulling task induces sensorimotor declines and neuromuscular inflammation increased numbers of pro-inflammatory macrophages and cytokines and fibrosis [ 7 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], yet effective preventive treatments that can be provided long-term are still needed i.
Additionally, the ibuprofen treatment and an anti-tumor necrosis factor drug failed to rescue task-induced somatosensory hypersensitivity [ 18 , 19 ].
