National Academy of Sports Medicine (NASM) Group Fitness Instructor Practice Exam

Which muscle is commonly underactive in the LPHC?

1. Quadriceps.

2. Gluteus Maximus.

3. Hamstrings.

4. Rectus Abdominis.

The correct answer is: Hamstrings.

In the context of the Lower Part of the Human Body (LPHC), the hamstrings can often be described as underactive, particularly in individuals who experience movement patterns that promote anterior pelvic tilt or excessive hip flexor tightness. When the hip flexors are tight and the gluteus maximus is overactive or inhibited, it can lead to a scenario in which the hamstrings do not engage adequately during activities such as squatting or lunging. The role of the hamstrings is vital in stabilizing the pelvis and aiding in proper hip extension. When they are underactive, it can contribute to compensation patterns that may lead to injury or inefficient movement mechanics. This condition is exacerbated in a population that may lead a sedentary lifestyle, where sitting for prolonged periods can further inhibit hamstring activation. Understanding the connection between muscle activation patterns and functional movement is critical for developing effective training and correction strategies in group fitness settings. This insight into muscle function is essential for group fitness instructors, as it allows for better coaching cues and programming that address muscle imbalances, ultimately leading to improved performance and reduced risk of injury among participants.