National Academy of Sports Medicine (NASM) Certified Personal Trainer (CPT) Practice Exam

Which muscles are part of the lateral subsystem?

1. Hamstrings and quadriceps

2. Gluteus medius and tensor fasciae latae

3. Deltoids and biceps

4. Rectus abdominis and pectorals

The correct answer is: Gluteus medius and tensor fasciae latae

The lateral subsystem is crucial for maintaining stability and proper movement patterns during functional tasks. It primarily consists of the gluteus medius and tensor fasciae latae, which work together to provide lateral stability and control during activities such as walking, running, and lateral movements. The gluteus medius is responsible for hip abduction, helping to stabilize the pelvis during single-leg activities. The tensor fasciae latae, in conjunction with the iliotibial band, assists in this action and contributes to the overall stability of the hip and knee. This duo is essential in preventing excessive motion that could lead to injuries, especially in the lower extremities. In contrast, the other muscle groups listed do not align with the functions of the lateral subsystem. The hamstrings and quadriceps (first option) are part of the anterior and posterior subsystems that focus on flexion and extension of the knee. The deltoids and biceps (third option) are more involved in upper body movements and stability rather than lateral stability. Finally, the rectus abdominis and pectorals (fourth option) are associated with anterior stability and flexion and do not provide the necessary lateral support characterized by the lateral subsystem.