MBLEx Kinesiology Questions and Answers — Questions and Answers
Question 1: A client is performing shoulder abduction, lifting their arm out to the side. In this movement, the deltoid is the prime mover. Which muscle acts as an antagonist to this action?
- Supraspinatus
- Pectoralis Major
- Latissimus Dorsi (Correct answer)
- Teres Minor
Correct answer: Latissimus Dorsi
The latissimus dorsi is a primary adductor of the shoulder, performing the opposite action of abduction. Therefore, it acts as the antagonist to the deltoid during shoulder abduction, relaxing to allow the movement to occur.
Question 2: Flexion and extension, such as in a bicep curl, occur primarily within which anatomical plane?
- Frontal (Coronal) Plane
- Transverse (Horizontal) Plane
- Sagittal Plane (Correct answer)
- Oblique Plane
Correct answer: Sagittal Plane
The sagittal plane divides the body into left and right halves. Movements that involve moving forward and backward, like flexion and extension, occur in this plane.
Question 3: A therapist is using a Proprioceptive Neuromuscular Facilitation (PNF) stretching technique. They ask the client to contract the quadriceps to encourage the hamstrings to relax and lengthen. This neurological principle is known as:
- Autogenic Inhibition
- Reciprocal Inhibition (Correct answer)
- Stretch Reflex
- Post-isometric Relaxation
Correct answer: Reciprocal Inhibition
Reciprocal inhibition is the process where muscles on one side of a joint relax to accommodate the contraction of muscles on the other side of the joint. When the agonist (quadriceps) contracts, the antagonist (hamstrings) is neurologically inhibited, allowing it to relax and be stretched more effectively.
Question 4: Which of the following joint types allows for movement in only one plane, such as the elbow or knee?
- Ball-and-socket joint
- Saddle joint
- Pivot joint
- Hinge joint (Correct answer)
Correct answer: Hinge joint
A hinge joint, or ginglymus joint, functions like a door hinge, permitting movement in only one plane (uniaxial), which allows for flexion and extension. The elbow (humeroulnar) and interphalangeal joints are classic examples.
Question 5: During a massage, a therapist applies slow, sustained pressure to a tight muscle. After about 30 seconds, the therapist feels the muscle begin to relax. This relaxation response is primarily mediated by which proprioceptor?
- Muscle Spindle
- Golgi Tendon Organ (Correct answer)
- Pacinian Corpuscle
- Ruffini's End Organ
Correct answer: Golgi Tendon Organ
The Golgi Tendon Organ (GTO) is a proprioceptor that senses changes in muscle tension. When tension increases to a certain point (as with sustained pressure), the GTO is stimulated and causes a reflex relaxation of the muscle (autogenic inhibition) to protect it from injury.
Question 6: When performing a push-up, the triceps brachii contracts to straighten the elbow and push the body up. In this movement, what role does the pectoralis major play?
- Antagonist
- Fixator
- Synergist (Correct answer)
- Neutralizer
Correct answer: Synergist
A synergist muscle assists the prime mover in performing an action. During a push-up, the triceps brachii is a prime mover for elbow extension, and the pectoralis major acts as a powerful synergist, assisting in the overall pushing movement by flexing and adducting the shoulder.
MBLEx Kinesiology Questions and Answers
A client is performing shoulder abduction, lifting their arm out to the side.
In this movement, the deltoid is the prime mover.
Which muscle acts as an antagonist to this action?