CSCS Resistance Training Biomechanics

Question 1

During the deadlift, which lumbar spine position minimizes compressive and shear forces and is considered biomechanically safest?

Accepted Answer

Neutral lumbar spine (maintaining natural lordotic curve)

Answer

Full lumbar flexion (rounded lower back)

Answer

Full lumbar extension (hyperextended lower back)

Answer

Lateral flexion to one side for load distribution

Question 2

What is the 'double-knee bend' technique in the power clean, and why does it occur?

Accepted Answer

A natural re-flexion of the knees during the transition phase that positions the hips for the explosive second pull

Answer

A re-bending of the knees during the catch phase to safely absorb the bar at the front rack position

Answer

A deliberate coaching technique requiring two separate knee flexion phases before the initial pull

Answer

A technique error indicating the lifter is not maintaining proper bar path during the first pull

Question 3

What is the primary biomechanical difference between the high-bar and low-bar back squat?

Accepted Answer

Low-bar squat primarily targets the quadriceps compared to the posterior chain in high-bar

Answer

Low-bar squat requires greater squat depth than high-bar squat

Answer

High-bar squat produces more forward torso lean while low-bar allows a more upright torso

Answer

High-bar squat requires greater hip mobility due to the more forward lean required

Question 4

At which point in the squat is knee extensor torque greatest, and why?

Accepted Answer

At or near parallel (90 degrees knee flexion) where the knee external moment arm is maximized

Answer

At the top of the movement (standing position) due to full body weight loading on the joint

Answer

During the concentric acceleration phase (halfway up) due to maximum velocity

Answer

At the eccentric-concentric transition point due to stretch-shortening cycle activation

Question 5

What is the NSCA-recommended bar placement and stance width for a beginner learning the back squat?

Accepted Answer

High-bar position, slightly wider than shoulder-width stance, toes angled 30-35 degrees outward

Answer

High-bar position, shoulder-width stance, toes pointing straight forward

Answer

Low-bar position, wide sumo stance, toes angled 45 degrees outward

Answer

Bar resting on the neck, narrow stance, toes pointing forward

Question 6

What is 'dynamic knee valgus collapse' during landing, and why is it biomechanically dangerous?

Accepted Answer

Medial displacement of the knee during landing that simultaneously stresses the ACL and MCL, the primary non-contact ACL injury mechanism

Answer

Excessive knee hyperextension in the sagittal plane, increasing posterior cruciate ligament tension

Answer

Lateral knee shift during single-leg landing that excessively loads the IT band

Answer

Posterior tibial translation during landing that strains the PCL and posterior capsule