Assesment of Post-stroke Elbow Flexor Spasticity in Different Forearm Positions

There are three main muscles that contribute to elbow flexor spasticity; musculus biceps brachii, musculus brachialis and musculus brachioradialis. Muscle selection in elbow flexor spasticity for botulinum toxin application has impact on treatment outcome. The superficiality of the biceps brachii muscle makes it an easy target for botulinum toxin injection. In dynamic electromyography studies, it has been reported that brachioradialis muscle is the most common contributor one to elbow flexion spasticity, followed by biceps brachii muscle. In the diagnostic selective nerve blocks, the brachialis muscle has been reported to be foreground.

Determination of which muscle is more spastic before injection of the botulinum toxin, and the application of the targeted treatment to that muscle results in more improvement in spasticity. Can the target muscle selection clinically be performed instead of methods such as electromyography where equipment is required and the evaluation period is relatively long? Can semi-quantitative methods used to assess the severity of spasticity provide reliable information regarding the muscle or muscles that contribute to elbow flexor spasticity? It is known that the muscles that flex elbow in healthy individuals change according to forearm position. While the biceps brachii flexes the forearm in supination, the brachioradialis flexes the forearm in the neutral position. The brachialis muscle acts as a primary flexor muscle when the forearm is in pronation.

The aim of this study is to investigate whether the severity of spasticity differs depending on the forearm position.

Inclusion criteria

• Elbow flexor spasticity
• Grade 1 to 3 spasticity measured with Modified Ashworth Scale
• To agree to participate in the study

Exclusion criteria

• <18 years old
• Pregnancy
• Botulinum toxin injection within the last three months
• Presence of elbow contracture
• History of operation to spastic upper extremity
• Spasticity due to other causes other than stroke
• Do not agree to participate in the study