ACE ACE Anatomy & Biomechanics 2 — Questions and Answers
Question 1: Which muscle is the primary stabilizer of the lumbar spine and is often targeted with core stability exercises in group fitness?
- Rectus abdominis
- Iliopsoas
- Transverse abdominis (Correct answer)
- Erector spinae
Correct answer: Transverse abdominis
The transverse abdominis is the deepest abdominal muscle that acts like a corset to stabilize the lumbar spine before limb movement occurs.
Question 2: What is the term for the phase of a muscle contraction in which the muscle lengthens while under tension?
- Concentric contraction
- Isometric contraction
- Eccentric contraction (Correct answer)
- Isokinetic contraction
Correct answer: Eccentric contraction
An eccentric contraction occurs when a muscle produces force while lengthening, such as lowering a weight under control.
Question 3: During a lunge, which muscle group performs a concentric contraction to return the participant to the starting position?
- Hamstrings and calf muscles
- Quadriceps and gluteus maximus (Correct answer)
- Hip adductors and tibialis anterior
- Obliques and erector spinae
Correct answer: Quadriceps and gluteus maximus
The quadriceps extend the knee and the gluteus maximus extends the hip concentrically to propel the body back to the upright starting position.
Question 4: What anatomical structure connects muscle to bone and transmits muscular force to produce joint movement?
- Ligament
- Bursa
- Tendon (Correct answer)
- Fascia
Correct answer: Tendon
Tendons are dense connective tissue structures that attach muscle to bone, transmitting the contractile force to create skeletal movement.
Question 5: Which of the following best describes pronation of the forearm?
- Rotating the forearm so the palm faces upward
- Rotating the forearm so the palm faces downward (Correct answer)
- Bending the elbow toward the shoulder
- Extending the wrist backward
Correct answer: Rotating the forearm so the palm faces downward
Forearm pronation is the rotational movement that turns the palm from facing up to facing down.
Question 6: What is the kinetic chain concept, and why is it important for group fitness instruction?
- It refers only to upper body muscle sequencing during pushing movements
- It describes how forces and movements are transmitted through interconnected body segments (Correct answer)
- It is a method of measuring joint torque in isolation
- It applies only to athletes, not general fitness participants
Correct answer: It describes how forces and movements are transmitted through interconnected body segments
The kinetic chain concept recognizes that the body's segments are interconnected, so dysfunction or instability in one area can affect movement quality and injury risk throughout the chain.
ACE ACE Anatomy & Biomechanics 2
Which muscle is the primary stabilizer of the lumbar spine and is often targeted with core stability exercises in group fitness?