NFPT - National Federation of Professional Trainers Human Anatomy and Biomechanics Questions and Answers — Questions and Answers
Question 1: During the upward phase of a bicep curl, the biceps brachii is shortening while generating force. Which type of muscle contraction is occurring, and what is the role of the biceps brachii?
- Eccentric contraction, Antagonist
- Isometric contraction, Stabilizer
- Concentric contraction, Agonist (Correct answer)
- Isokinetic contraction, Synergist
Correct answer: Concentric contraction, Agonist
A concentric contraction occurs when a muscle shortens under tension. The biceps brachii is the prime mover, or agonist, for elbow flexion, which is the primary movement in a bicep curl. Therefore, during the upward phase, the biceps brachii performs a concentric contraction and acts as the agonist.
Question 2: A client is performing a lateral raise with dumbbells. This movement primarily occurs in which anatomical plane?
- Sagittal Plane
- Frontal (Coronal) Plane (Correct answer)
- Transverse Plane
- Oblique Plane
Correct answer: Frontal (Coronal) Plane
The frontal (or coronal) plane divides the body into anterior (front) and posterior (back) sections. Movements in this plane are side-to-side, such as abduction and adduction. A lateral raise involves shoulder abduction, moving the arms out to the sides, which is a classic frontal plane movement.
Question 3: Which of the following describes the biomechanical role of the triceps brachii during the downward (lowering) phase of a traditional push-up?
- Agonist performing an eccentric contraction (Correct answer)
- Antagonist performing a concentric contraction
- Synergist performing an isometric contraction
- Stabilizer performing an isotonic contraction
Correct answer: Agonist performing an eccentric contraction
In a push-up, the triceps are a prime mover (agonist) for elbow extension (the upward phase). During the downward phase, gravity is pulling the body down. The triceps must lengthen under tension to control this descent. This is an eccentric contraction. Since the triceps are controlling the primary movement, they are still considered the agonist in this phase.
Question 4: A client performing a squat exhibits a significant forward lean of the torso. From a biomechanical perspective, this compensation primarily increases the demands on which muscle group?
- Quadriceps
- Abdominals
- Erector Spinae (Correct answer)
- Adductors
Correct answer: Erector Spinae
Leaning the torso forward during a squat increases the flexion moment at the hip and lumbar spine. To counteract this and prevent the torso from collapsing, the erector spinae muscles, which run along the spine, must work significantly harder to maintain spinal extension and stability.
Question 5: When performing a standing cable wood chop, the rotational movement of the torso occurs in which plane of motion?
- Frontal Plane
- Sagittal Plane
- Coronal Plane
- Transverse Plane (Correct answer)
Correct answer: Transverse Plane
The transverse plane divides the body into superior (upper) and inferior (lower) halves. Rotational movements, such as twisting the torso in a wood chop exercise, occur within this plane.
Question 6: During a lunge, the gluteus maximus is the prime mover for hip extension. The hamstrings assist in this motion. What is the functional role of the hamstrings in this scenario?
- Antagonist
- Fixator
- Synergist (Correct answer)
- Agonist
Correct answer: Synergist
A synergist muscle is one that assists the prime mover (agonist) in performing a specific joint action. In the case of hip extension during a lunge, the gluteus maximus is the agonist, and the hamstrings act as synergists to help produce the movement.
NFPT - National Federation of Professional Trainers Human Anatomy and Biomechanics Questions and Answers
During the upward phase of a bicep curl, the biceps brachii is shortening while generating force.
Which type of muscle contraction is occurring, and what is the role of the biceps brachii?