IFPA Trainer Practice Exam

In the bent knee position, the soleus performs almost what percentage of the work?

1. 90%

2. 50%

3. 85%

4. 60%

The correct answer is: 85%

In the bent knee position, the soleus muscle is primarily responsible for plantar flexion of the ankle, especially when the knee is flexed. This occurs because the gastrocnemius, another major calf muscle, is less active in this position due to its origin across the knee joint. As the knee bends, the ability of the gastrocnemius to contribute to plantar flexion diminishes, allowing the soleus to take on a greater share of the workload. Research indicates that the soleus provides about 85% of the work in plantarflexion when the knee is bent. This significant contribution is crucial for various activities such as walking, running, and jumping, where effective propulsion is needed while the knee is flexed. Understanding this distribution of work helps in designing tailored training and rehabilitation programs that focus specifically on strengthening the soleus and other muscles involved in lower limb movement and stability.