Enhance Sensory Input on Reversing the Quadriceps Inhibition in Individuals with Acl Deficiencies

Anterior cruciate ligament (ACL) is vulnerable to injury. In individuals with ACL deficiency, quadriceps weakness and atrophy are very common. Following ACL deficiency, the voluntary activation level was found to be decreased which, thus, worsen the symptom of quadriceps weakness. In addition, the motor evoked potential elicited by transcranial magnetic stimulation was revealed to be decreased in ACL deficiency, but these changes were not significant. Part of the reasons might be due to the level of deficiencies were varied across subjects. Finding the correlation between the clinical symptoms and the excitability of motor pathways will be helpful to understand the contribution of neural factors to the quadriceps weakness in ACL deficiencies. The conventional training program for individuals with ACL deficiencies focused on the voluntary strength training. However, due to the neural inhibition, some muscular structure could not be activated. Training program focus on decreasing neural inhibition needed to be developed in individuals with ACL deficiencies. In reviewing of past researches, sensory level electrical stimulation at a intensity just above motor threshold found to be effective in enhancing the motor pathway excitability. Therefore, adding sensory stimulation to the conventional strength training program might be helpful to reverse the quadriceps weakness in individuals with ACL deficiencies. There are two purposes in this project and will be executed in two years. The purpose of the first year’s study is to investigate the correlation of the clinical symptoms of quadriceps weakness to the neural factors,. The purpose of the second year’s study is to develop a training program which emphasize on increasing motor pathway excitability and to compare the effect to that of conventional strength training program. The results of this project will help researchers, rehabilitation specialists, athlete trainers, and coaches to understand the neural factors that limit the functional performance in ACL deficiencies. In addition, this project will establish an effective training program to reverse the quadriceps weakness for ACL deficiencies.

Project ID:PC9709-0460
External Project ID:NSC97-2410-H182-017