Semiportable Manually Actuated System for Measuring Muscle Spasticity

In the article, we describe a design of a new system which provides means to quantitatively assess passive resistance of skeletal muscles, also termed muscle spasticity. New design is focused on the measurement of muscle groups which are responsible for movement of elbow joint. The semiportable system is an alternative to expensive motorized isokinetic dynamometers. System is manually actuated dynamometer. The electronic subsystem of the system is used to measure angular velocity and torque in the elbow joint. An incremental encoder is used for the measurement of angular velocity. The angular velocity of the rotational movement in a joint is a result of movement effected by manually controlled lever. The lever is controlled by a physician. During the angular movement of the upper limb segments, the elbow joint torque is measured by a strain gauge subsystem. The output from the system is a graphic dependence between the angular velocity and the torque, which is used to evaluate spasticity. The dependence between the passive moment of force and kinematic angular parameters allows us to study complex motion and force possibilities of the joint. The designed system could be useable and widely applicable in clinical practice, as well as research of diseases and treatment of musculoskeletal system.