The soleus is a muscle located in the calf that primarily functions to plantarflex the foot at the ankle joint. While it is not directly involved in knee extension, it plays a supportive role during activities that require knee extension, such as standing or walking. By stabilizing the ankle, the soleus helps maintain proper alignment and function of the leg, allowing for more effective knee extension by the quadriceps muscle. Thus, its indirect contribution is important for overall lower limb mechanics.
soleus
The quadriceps muscles are primarily involved in knee extension.
The primary function of the knee extension muscle is to straighten the leg by extending the knee joint.
An agonist muscle is a muscle that plays a part in the extension of a muscle. The agonist muscles for a knee extension are the quadriceps and hamstrings.
The soleus muscle is more emphasized in the seated calf raise because of its anatomical position and function. When seated, the knee is flexed, which reduces the involvement of the gastrocnemius muscle, allowing the soleus to take on a greater role in plantarflexion. In contrast, during standing raises, the gastrocnemius is more engaged due to its dual functionality at the knee and ankle joints, leading to less isolation of the soleus. Thus, the seated position effectively targets the soleus more directly.
Gastrocnemius and Soleus with leg straight, to isolate gastrocnemius bend knee.
Knee extension is primarily a sagittal plane movement that involves extension of the knee joint, resulting in straightening of the leg. It does not involve any specific type of rotation.
Vertebral Foraminal Entrapment on Hip Flexion and Knee Extension
The antagonists would be those muscles that cause knee flexion. Hamstrings (biceps femoris, semimembranosus, semitendonosis) are the primary knee flexors, and would thus be antagonists to knee extension.
knee extension
Knee extension
Extension. Extension increases an angle, as in straightening a joint. During extension, the knee or elbow are straightened.