Biomechanical Analysis & Movement Flashcards

In biomechanical analysis, what does the term 'moment arm' refer to?

Answer: The perpendicular distance from the joint axis to the line of force

The moment arm is the perpendicular distance from the joint's axis of rotation to the line of action of a force, determining torque magnitude.

Which postural deviation is characterized by an exaggerated thoracic kyphosis combined with a flattened lumbar curve?

Answer: Sway-back posture

Sway-back posture features increased thoracic kyphosis, a posteriorly shifted pelvis, and a flattened lumbar spine.

The 'Q-angle' is a measurement used to assess alignment of which joint?

Answer: Knee

The Q-angle measures the quadriceps angle at the knee, formed between the line from the ASIS to the patella and the patellar tendon to the tibial tubercle.

What is the primary role of the deep longitudinal subsystem (DLS) during gait?

Answer: Force transmission from the foot through the ipsilateral posterior chain

The DLS (biceps femoris, sacrotuberous ligament, erector spinae) transmits ground reaction forces from the foot up through the posterior kinetic chain.

During a squat, excessive forward lean of the torso is most likely caused by which limitation?

Answer: Limited ankle dorsiflexion

Limited ankle dorsiflexion forces the trunk to lean forward excessively to keep the center of mass over the base of support during a squat.

Which law states that a bone will remodel along the lines of mechanical stress placed upon it?

Answer: Wolff's Law

Wolff's Law states that bone adapts its internal architecture and external shape in response to the mechanical loads applied to it.

In a first-class lever system, where is the fulcrum located relative to the effort and resistance?

Answer: Between the effort and the resistance

In a first-class lever, the fulcrum (joint) lies between the effort (muscle force) and the resistance (load), like a seesaw.