Intervertebral disc degenerations are the most important cause of chronic low back pain resulting in job loss and associated socio-economic problems in developed and developing industrial countries 1. More than 40% of the Turkish population has experienced low back pain at least once in their life 2. Intervertebral disc degenerations Lumbal Disc Herniation (LDH), which is frequently represented, can cause motor and sensory losses in the lower extremity by compressing the spinal nerves. Lumbar disc surgery procedure is inevitable in case of advanced functional losses in the related sensory dermatomes and muscles after LDH. Lumbal disc surgeries are performed for the purpose of decompression of nerve pressures on nerves due to advanced disc herniation. they suggest 4.

One of the most common LDH problems in the community is low foot problems due to weakness of the tibialis anterior muscle, which occurs due to L4-L5 disc herniation, and the accompanying functional disorders. In disc herniations at this level, the activation of the tibialis anterior muscle, which is compressed by the nerve root, decreases compared to the medial gastrocnemius muscle, where it works as an antagonist, and this leads to functional limitations, especially in gait and balance activities.

Spinal stabilization exercises are a concept that emerged from the idea that exercise is important for the provision and preservation of functionality of people with low back and back pain due to LDH. According to this exercise approach, muscles are of great importance in providing lumbar region stability. These muscles are classified as general (global) stabilizing muscles, which are dynamic, phasic, and power-producing muscles, and regional (local) stabilizing muscles, which are postural, tonic, and stabilizer muscles. The main muscles responsible for spine stabilization are multifidus, transversus abdominus and pelvic floor muscles 6. It is argued that increased lumbo-pelvic motor control thanks to spine stabilization facilitates lower extremity activities, especially flexion and extension movements in the sagittal plane. Patients with LDH who increase their motor strength can use lower extremity movements more functionally.

The aim of this study was to (1) determine the activation rates of the tibialis anterior and medial gastrocnemius muscles during different functional activities in the lower extremities affected and unaffected by LDH, (2) to compare the rates of the affected extremity to the rates of the healthy extremity during coactivation of the transversus abdominus and multifidus muscles (spinal stabilization basic exercise). to determine whether it is close or not. According to the hypothesis of this study, the researchers thought that the functional activities performed together with the activation of the transversus abdominus and multifidus muscles would show coactivation behaviors at a rate closer to the healthy extremity.

Inclusion Criteria:

• Being between the ages of 18-65
• To be diagnosed with LDH at the minimum level of protrusion by the physician
• Diagnosis confirmed by the physician in charge of the study by computed tomography (CT) or magnetic resonance imaging (MRI) reports

Exclusion Criteria:

• Having bilateral LDH findings,
• have an acute illness
• Having significant neurological disease other than LDH (such as head trauma, brain abscess, brain tumor, migraine attack, seizure)
• Having trauma or congenital orthopedic disorders that prevent lower extremity functions other than LDH
• Not being able to adapt to the study cognitively.