The aim of this study was to evaluate the architectural changes and muscle stiffness of the upper and lower extremity muscles in our hemiplegic patients ultrasonographically and to investigate their relationship with clinical assessment scales.

Spasticity has been defined as "disorganized sensorimotor control resulting from upper motor neuron lesion, manifested as intermittent or continuous involuntary activation of muscles". Its high prevalence and limited effectiveness of current treatment options make spasticity an important health problem in neurological rehabilitation.

The commonly used tools for the assessment of spasticity are subjective clinical scales, including the Ashworth Scale (AS), Modified AS (MAS), Tardieu Scale (TS), Modified TS (MTS), and Tone Assessment Scale (TAS). Most of these scales have limitations regarding reliability and inter-examiner reproducibility. Many uncontrollable or unstable factors can affect the measurement results.

On the other hand, spasticity can be assessed objectively using isokinetic dynamometers or electromyography (EMG). However, EMG data can be affected by various factors (electrode placement, muscle atrophy, skin resistance, etc.). These quantitative and objective methods require technological skills and equipment and can only assess a limited number of muscles. Ultrasonography has been used to determine muscle size (muscle length and volume), architectural features (thickness, cross-sectional area, fascicle length, and pennation angle), as well as content features (e.g., stiffness) of spastic muscles in patients with central nervous system injuries. In clinical practice, muscle atrophy-loss of contractile tissue-is usually measured by cross-sectional area or thickness (reflecting cross-sectional area) in spastic patients. Ultrasound is also useful for measuring fascicle length and pennation angle, architectural features that determine the muscle movement and force generated along the line of tension, respectively. The fascicle length of the affected muscle on the hemiparetic side of stroke patients was found to be shorter than in nonparetic and healthy controls. In addition to architectural changes, excessive stiffness felt during movement of the segments around the joint causes movement impairment in patients with spasticity. Ultrasound elastography has recently enabled physicians to accurately measure passive muscle stiffness. It has been found that spastic muscle stiffness increases in patients with central nervous system injuries.

Muscles frequently evaluated by ultrasound elastography are biceps and gastrocnemius muscles, which are reported to be highly affected by spasticity. However, the lack of a standard measurement protocol and the variability of elasticity in patients need to be addressed. Since there are few studies investigating the application of ultrasound elastography techniques for measuring muscle stiffness, future studies are needed to understand the mechanical properties of the muscles and to obtain a standard and reliable protocol. In the literature, only one study has evaluated forearm muscles elastographically and found that the elasticity ratio was lower on the hemiplegic side compared to the non-hemiplegic side.

The aim of this study was to evaluate the architectural changes and muscle stiffness of the upper and lower extremity muscles in our hemiplegic patients ultrasonographically and to investigate their relationship with clinical assessment scales.

Inclusion Criteria:

• Age 40-70
• Unilateral hemiplegia
• At least 3 months since cerebrovascular accident

Exclusion Criteria:

• Operation or fracture in the last 3 months
• Botulinum toxin injection in the last 6 months

100 hemiplegic patients aged between 40-70 years, with unilateral hemiplegia, and at least 3 months after a cerebrovascular accident, who applied to the AFSU Department of Physical Medicine and Rehabilitation will be included.