Biomechanical Muscle Properties and Balance in Children With Spastic Hemiplegia

oscillatory frequency

The MyotonPro (Myoton AS Tallinn, Estonia) device will be used to assess oscillation frequency. it introduces an innovative and non-invasive approach for comprehensively characterizing the biomechanical and viscoelastic properties of muscles.The device is applied under constant preload (0.18 N) to pre-compress subcutaneous tissues, and it exerts a brief (15 milliseconds) mechanical tap at a pre-determined force (0.4 Newtons), followed by quick release, causing damped oscillations that are recorded by the testing probe. This device is portable, inexpensive, easy to use, and convenient for re-cording the biomechanical and viscoelastic stiffness of myofascial tissues relatively quickly.A higher oscillation frequency indicates higher muscle tone, while increased stiffness reflects greater resistance to force application.

Limits of stability

HUMAC balance system will be used to assess limits of stability.Limits of stability are known as the maximum distance a subject is able to move his/her COP in different directions while keeping the configuration of the BOS and while remaining stable.The test will be conducted at level 4, which represents the degree of distance to the farthest target. At this level, the task is considered relatively simple, as the distance between the center target and each surrounding target is minimal. Higher values obtained during the test indicate better performance.

center of pressure

HUMAC balance system will be used to assess center of pressure

muscle dynamic stiffness

The MyotonPro (Myoton AS Tallinn, Estonia) device will be used to assess muscle dynamic stiffness. it introduces an innovative and non-invasive approach for comprehensively characterizing the biomechanical and viscoelastic properties of muscles.The device is applied under constant preload (0.18 N) to pre-compress subcutaneous tissues, and it exerts a brief (15 milliseconds) mechanical tap at a pre-determined force (0.4 Newtons), followed by quick release, causing damped oscillations that are recorded by the testing probe. This device is portable, inexpensive, easy to use, and convenient for re-cording the biomechanical and viscoelastic stiffness of myofascial tissues relatively quickly.A higher dynamic stiffness indicates greater resistance to force application.

The modified clinical test of sensory integration of balance

HUMAC balance system will be used to assess sensory integration of balance or stability score.This test begins with the participant standing on the HUMAC board with the middle of his/her feet lined up with the 7's on the horizontal axis, and the medial malleolus lined up with a letter along the vertical axis. The child will be instructed to stand in a neutral position with his/her arms beside the body for thirty seconds. As participants completed the test, the board monitored their COP to determine their stability score and path length. the score determined patient stability. A higher score indicates more stability, and a lower score indicates lower stability.

muscle elasticity

the MyotonPro (Myoton AS Tallinn, Estonia) device will be used to assess muscle elasticity. it quantifies the dissipation of mechanical energy (damping) during natural oscillations of a muscle. lower values signify higher elasticity (i.e., better ability to recover from deformation), while higher values suggest lower elasticity.

mechanical stree relaxation time

the MyotonPro (Myoton AS Tallinn, Estonia) device will be used to assess mechanical stree relaxation time with ms.It represents the duration of the muscle recovery process (or the relaxation time) from displacement.the higher tissue tension or stiffness, the faster tissue recovers its shape, meaning the lower the value.