P292: Features of patellar pendulum triggered by patella T reflex in rigidity

Parkinson’s disease is a movement disorder characterized by an increase in muscle tone. Rigidity affects motor capacity and daily functions of the patients. Aim of the study is analyzing electrophysiologically and kinesiologically features of the patellar pendulum that was triggered by patella T reflex in the Parkinson patients with rigidity. Method: We stimulated patella T reflex by an electronic triggered reflex hammer and recorded muscle action potenteials by surface electrodes from quadriceps femoris and biceps femoris muscles. We analyzed electrophysiological features of patellar T reflex and also analyzed characteristics of the patellar pendulum during the reflex motion in patients with rigidity and normal subjects. Joint angle changes and instantaneous angular velocity during reflex was measured with a goniometric approach. Results: Twenty five normal subjects included study as a control group. Patella T reflex had 17.9±1.9 milliseconds latency and 6404.1±2860.0 microvolt amplitude. Initial time of joint motion was 51.5±9.9 milliseconds and it was measured with an accelerometer. The pendulum count was 4.8±1.5. Angle of joint motion was 18.3±5.6°; extension time was 317.4±23.4 milliseconds; instantaneous angular velocity was 58.0±16.6 degrees/second; frequency was 1.0±0.1. Damping ratio of the pendulum was calculated as 0.6±0.2. A parameter was developed using by significant kinesiological findings and it was 60.3±16.1 degrees/second*Hz. There were 45 Parkinson’s disease patients in the rigidity group. Patella T