Menu

Physiology & Rehabilitation MCQs

Practice Set 3 of 26

This practice set contains high-yield board review questions covering key concepts in Physiology & Rehabilitation. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 41

Topic: Physiology & Rehabilitation

During the normal human gait cycle, which muscle or muscle group undergoes an essential eccentric contraction during the initial contact (heel strike) to loading response phase to prevent a 'foot slap' mechanism?

. Gastrocnemius-soleus complex
. Quadriceps femoris
. Hamstrings
. Tibialis anterior
. Gluteus maximus

Correct Answer & Explanation

. Tibialis anterior

Explanation

The tibialis anterior contracts eccentrically (lengthens under tension) immediately following heel strike to decelerate plantarflexion and gently lower the forefoot to the ground, preventing 'foot slap'.

Question 42

Topic: Physiology & Rehabilitation

Which of the following skeletal dysplasias is not commonly associated with non-orthopedic complications:

. McKusick metaphyseal chondrodysplasia
. Hurler syndrome
. Morquio syndrome
. C hondroectodermal dysplasia
. Multiple epiphyseal dysplasia

Correct Answer & Explanation

. Multiple epiphyseal dysplasia

Explanation

McKusick dysplasia is commonly associated with immune and gastrointestinal disorders. Hurler syndrome is associated with progressive mental retardation, hepatosplenomegaly, and cataracts. Morquio syndrome is associated with cardiorespiratory difficulties. C hondroectodermal dysplasia, or Ellis van C reveld syndrome, is associated with congenital heart disease. Multiple epiphyseal dysplasia, however, is not associated with systemic non- orthopaedic complications.

Question 43

Topic: Physiology & Rehabilitation

A 33-year-old woman with a history of a traumatic fall onto her wrist and tenderness over the scapholunate (SL) interval presents to the clinic. Radiographs are normal, and magnetic resonance imaging reveals a partial tear of the SL ligament. The remaining wrist ligaments are normal. If conservative therapy is attempted, then it should consist of:

. Short arm casting for 2 months
. Activity modification and wrist extension stretching
. Splinting and flexor carpi radialis training
. Splinting and flexor carpi ulnaris training
. C orticosteroid injection into the midcarpal space

Correct Answer & Explanation

. Splinting and flexor carpi radialis training

Explanation

Conservative management includes a period of splinting and activity modification, followed by proprioception training of the flexor carpi radialis to act as a dynamic scaphoid stabilizer.

Question 44

Topic: Physiology & Rehabilitation

Compared to operative management of acute Achilles tendon ruptures, recent level I evidence regarding non-operative management utilizing early functional rehabilitation demonstrates:

. Higher deep vein thrombosis rates in non-operative patients
. Lower rates of wound complications and infections
. Significantly higher re-rupture rates (>20%)
. Decreased range of motion at 1 year post-injury
. Improved peak isokinetic plantar flexion strength

Correct Answer & Explanation

. Lower rates of wound complications and infections

Explanation

Recent trials utilizing early functional rehabilitation show similar re-rupture rates and functional outcomes between operative and non-operative management. However, non-operative management avoids the wound healing complications and infection risks associated with surgery.

Question 45

Topic: Physiology & Rehabilitation

Which of the following statements about the gait cycle is true:

. The swing phase is longer than the stance phase and lasts for 62% of the cycle.
. From heel rise to toe-off, the tibia goes into external rotation.
. At heel strike, the anterior tibialis muscle is quiescent.
. At toe-off, the gastroc-soleus complex is eccentric contracting.
. From heel strike to toe-off, the transverse tarsal joint unlocks.

Correct Answer & Explanation

. From heel rise to toe-off, the tibia goes into external rotation.

Explanation

Discussion Because gait cycle questions are common on examinations, remember the following points: Stance phase: 62% of cycle Swing phase: 38% of cycle Muscle firing Electromyography findings during gait cycle: Muscle Activity Heel strike Anterior tibialis Gastroc-soleus Eccentric contraction Quiet Foot flat Anterior tibialis Gastroc-soleus Quiet Eccentric contraction Heel-off Gastroc-soleus C oncentric contraction Toe-off Gastroc-soleus C oncentric contraction Subtalar joint Heel strike to foot flat: Three important points Eversion of the subtalar joint Unlocking of the transverse tarsal joint Internal rotation of the tibia Heel rise to toe-off Inversion of the subtalar joint Locking of the transverse tarsal joint External rotation of the tibia

Question 46

Topic: Physiology & Rehabilitation

Radial tears of the meniscus are known to cause rapid progression of knee osteoarthritis compared to simple longitudinal tears. This is primarily because a complete radial tear directly abolishes which meniscal function?

. Direct vertical load shock absorption through the extra-cellular matrix
. The generation and distribution of circumferential hoop stresses
. Distribution of joint lubrication and synovial fluid
. Proprioception mediated by capsular mechanoreceptors
. Secondary restraint to anterior tibial translation

Correct Answer & Explanation

. The generation and distribution of circumferential hoop stresses

Explanation

The primary biomechanical function of the meniscus relies on Type I collagen fibers arranged circumferentially to distribute axial loads as hoop stresses. A radial tear transects these fibers, effectively eliminating this load-sharing capacity.

Question 47

Topic: Physiology & Rehabilitation

Which of the following muscles is the primary hip abductor and is crucial for maintaining pelvic stability during the single-leg stance phase of gait?

. Gluteus maximus
. Iliopsoas
. Rectus femoris
. Gluteus medius
. Adductor longus

Correct Answer & Explanation

. Gluteus medius

Explanation

Correct Answer: DThe gluteus medius is the primary hip abductor and plays a critical role in stabilizing the pelvis during the single-leg stance phase of gait. Along with the gluteus minimus, it prevents the contralateral hip from dropping (a phenomenon known as the Trendelenburg sign or gait). The gluteus maximus is a powerful hip extensor. The iliopsoas is the primary hip flexor. The rectus femoris is a hip flexor and knee extensor. The adductor longus is a hip adductor.

Question 48

Topic: Physiology & Rehabilitation
A 65-year-old male with pre-existing cervical spondylotic stenosis falls forward and strikes his chin on a table, sustaining a severe hyperextension injury to his neck. He arrives at the trauma bay with significant bilateral motor weakness that is noticeably more profound in his upper extremities than his lower extremities, particularly affecting his hands. Proprioception and perianal sensation remain largely intact. What is the most likely diagnosis?
. Anterior cord syndrome
. Brown-Sรฉquard syndrome
. Central cord syndrome
. Posterior cord syndrome
. Conus medullaris syndrome

Correct Answer & Explanation

. Central cord syndrome

Explanation

Central cord syndrome frequently occurs in elderly patients with pre-existing cervical spondylosis who sustain hyperextension injuries. It is classically characterized by disproportionate motor impairment in the upper extremities compared to the lower extremities, often with varied sensory sparing.

Question 49

Topic: Physiology & Rehabilitation

An 18-month-old male presents with bilateral genu varum. The parents are concerned about his bowed legs since he began walking at 10 months. Which of the following radiographic parameters is the strongest predictor that his deformity will progress to infantile Blount disease rather than resolve as physiologic bowing?

. Metaphyseal-diaphyseal angle greater than 16 degrees
. Tibiofemoral angle of 10 degrees varus
. Metaphyseal-diaphyseal angle less than 11 degrees
. Symmetrical bowing involving both the femur and the tibia
. Lateral thrust noted during the stance phase of gait

Correct Answer & Explanation

. Metaphyseal-diaphyseal angle greater than 16 degrees

Explanation

The metaphyseal-diaphyseal angle (Drennan's angle) is crucial for differentiating physiologic bowing from infantile Blount disease. An angle greater than 16 degrees has a high predictive value (up to 95%) for progression to Blount disease, whereas an angle less than 11 degrees typically indicates resolving physiologic bowing.

Question 50

Topic: Physiology & Rehabilitation

A 28-year-old male bodybuilder feels a pop in his anterior axilla while bench-pressing heavy weights. Exam reveals loss of the anterior axillary fold and weakness in internal rotation. Which specific anatomical segment is most commonly ruptured in this injury?

. Clavicular head of the pectoralis major at the musculotendinous junction
. Sternoclavicular head of the pectoralis major at the humeral insertion
. Pectoralis minor at the coracoid process
. Clavicular head of the pectoralis major at the humeral insertion
. Coracobrachialis at the conjoint tendon

Correct Answer & Explanation

. Sternoclavicular head of the pectoralis major at the humeral insertion

Explanation

Pectoralis major ruptures most commonly occur at the humeral insertion of the sternoclavicular head. The injury classically happens during eccentric contraction with the arm extended and externally rotated, such as during the descent phase of a bench press.

Question 51

Topic: Physiology & Rehabilitation

A 32-year-old bodybuilder feels a pop in his anterior axillary fold while performing a heavy bench press. He is diagnosed with a complete pectoralis major rupture. Which of the following best describes the anatomic location where this injury most commonly occurs?

. At the musculotendinous junction
. At the clavicular head origin
. At the sternal head origin
. At the tendon insertion on the lateral lip of the bicipital groove
. Within the muscle belly of the sternocostal head

Correct Answer & Explanation

. At the tendon insertion on the lateral lip of the bicipital groove

Explanation

The vast majority of pectoralis major ruptures in weightlifters occur as avulsions at the tendinous insertion onto the lateral lip of the bicipital groove of the humerus. These injuries typically happen during eccentric contraction.

Question 52

Topic: Physiology & Rehabilitation

A 22-year-old female presents after an MVC with anterior cord syndrome following a flexion teardrop fracture. Which of the following sensory or motor modalities will most likely remain intact on her physical examination?

. Motor function in the lower extremities
. Motor function in the upper extremities
. Pain and temperature sensation below the lesion
. Proprioception and vibratory sense below the lesion
. Voluntary bowel and bladder control

Correct Answer & Explanation

. Proprioception and vibratory sense below the lesion

Explanation

Anterior cord syndrome involves damage to the anterior two-thirds of the spinal cord (corticospinal and spinothalamic tracts), leading to loss of motor function and pain/temperature sensation. The posterior columns are spared, preserving proprioception, vibration, and fine touch.

Question 53

Topic: Physiology & Rehabilitation

The direct lateral (Hardinge) approach to the hip requires splitting the gluteus medius and vastus lateralis. To avoid denervation of the anterior portion of the abductor mechanism, the proximal split in the gluteus medius should safely not extend beyond what distance from the tip of the greater trochanter?

. 1 cm
. 3 cm
. 5 cm
. 8 cm
. 10 cm

Correct Answer & Explanation

. 5 cm

Explanation

The superior gluteal nerve traverses the gluteus medius approximately 3 to 5 cm proximal to the tip of the greater trochanter. Extending the split beyond 5 cm places the nerve at significant risk, which can lead to postoperative Trendelenburg gait.

Question 54

Topic: Physiology & Rehabilitation

Beyond protection, the nail unit serves crucial biomechanical roles. Which of the following best describes a primary biomechanical function of the nail plate in conjunction with the fingertip pulp?

. Facilitating thermoregulation of the digit.
. Acting as a counterforce for the pulp, essential for precision pinch and grip.
. Producing synovial fluid for the distal interphalangeal joint.
. Anchoring the flexor digitorum profundus tendon.
. Enhancing proprioception through specialized mechanoreceptors.

Correct Answer & Explanation

. Acting as a counterforce for the pulp, essential for precision pinch and grip.

Explanation

Correct Answer: BUnder theSurgical Anatomy and Biomechanicssection, in theBiomechanical Considerationssubsection, it states: 'The rigid nail plate provides dorsal support, acting as a counterforce to the tactile pulp, which is essential for precision pinch, grip, and fine motor manipulation.'Incorrect Options:A. Facilitating thermoregulation of the digit:While the digit has vascularity for thermoregulation, this is not a primary biomechanical function of the nail plate itself.C. Producing synovial fluid for the distal interphalangeal joint:Synovial fluid is produced by the synovial membrane lining the joint capsule, not the nail unit.D. Anchoring the flexor digitorum profundus tendon:The flexor digitorum profundus tendon inserts into the volar base of the distal phalanx, not the nail unit.E. Enhancing proprioception through specialized mechanoreceptors:While the fingertip is highly innervated and sensitive, the primary biomechanical role described for the nail plate is as a counterforce, not primarily proprioception enhancement.

Question 55

Topic: Physiology & Rehabilitation

A 5-year-old boy presents with calf pseudohypertrophy and proximal muscle weakness. Genetic testing confirms a mutation in the dystrophin gene. Which of the following best describes the inheritance pattern and the normal cellular function of the affected protein?

. Autosomal dominant; anchors actin to the sarcolemma
. X-linked recessive; anchors actin to the extracellular matrix via the dystroglycan complex
. Autosomal recessive; regulates calcium release from the sarcoplasmic reticulum
. X-linked dominant; forms gap junctions between myofibrils
. X-linked recessive; facilitates ATP binding during muscle contraction

Correct Answer & Explanation

. X-linked recessive; anchors actin to the extracellular matrix via the dystroglycan complex

Explanation

Duchenne Muscular Dystrophy is inherited in an X-linked recessive pattern. Dystrophin connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane.

Question 56

Topic: Physiology & Rehabilitation

Duchenne Muscular Dystrophy (DMD) is caused by an X-linked recessive mutation that leads to the absence of dystrophin. At the cellular level, what is the primary structural role of the dystrophin protein in healthy skeletal muscle?

. It acts as a voltage-gated calcium channel in the sarcoplasmic reticulum.
. It directly binds myosin heads to the actin filaments during contraction.
. It links the intracellular actin cytoskeleton to the extracellular matrix via the dystroglycan complex.
. It provides the structural framework for the Z-disc of the sarcomere.
. It regulates ATP hydrolysis within the mitochondria of type I muscle fibers.

Correct Answer & Explanation

. It links the intracellular actin cytoskeleton to the extracellular matrix via the dystroglycan complex.

Explanation

Dystrophin is a critical structural protein that stabilizes the sarcolemma by linking the intracellular actin cytoskeleton to the extracellular matrix through the dystrophin-associated glycoprotein complex. Its absence leads to membrane fragility, calcium influx, and eventual muscle necrosis.

Question 57

Topic: Physiology & Rehabilitation

Becker Muscular Dystrophy (BMD) and Duchenne Muscular Dystrophy (DMD) share the same genetic locus but differ clinically. Which of the following best explains the pathophysiological difference that results in BMD having a milder clinical course?

. BMD involves an autosomal dominant mutation sparing the X chromosome.
. BMD mutations cause a complete absence of dystrophin production.
. BMD mutations result in a truncated, partially functional dystrophin protein.
. BMD selectively affects type II muscle fibers while sparing type I.
. BMD is characterized by elevated up-regulation of utrophin that fully replaces dystrophin.

Correct Answer & Explanation

. BMD mutations result in a truncated, partially functional dystrophin protein.

Explanation

DMD is caused by out-of-frame mutations leading to an almost total absence of dystrophin. BMD is caused by in-frame mutations, resulting in a shortened but partially functional dystrophin protein, yielding a milder phenotype.

Question 58

Topic: Physiology & Rehabilitation

In terms of meniscal innervation, which region is primarily responsible for proprioceptive feedback?

. The inner one-third (white-white zone).
. The central body, along its inferior surface.
. The anterior and posterior horns, particularly the vascularized periphery.
. The entire articular surface equally.
. Only the attachments to the tibial plateau.

Correct Answer & Explanation

. The anterior and posterior horns, particularly the vascularized periphery.

Explanation

Correct Answer: CThe menisci are innervated primarily in their vascularized periphery, particularly the anterior and posterior horns. Mechanoreceptors (Ruffini endings, Pacinian corpuscles, Golgi tendon organ-like endings) and free nerve endings are concentrated in these regions, contributing to proprioception and nociception. The inner two-thirds (white-white zone) are largely aneural and thus lack significant innervation for proprioception.

Question 59

Topic: Physiology & Rehabilitation

When performing an open tibiotalar arthrodesis for end-stage ankle osteoarthritis, achieving the correct position is critical for an energy-efficient gait and to protect adjacent joints. Which of the following represents the optimal position for ankle fusion?

. 5 degrees of plantarflexion, 5 degrees of valgus, and 15 degrees of external rotation
. Neutral dorsiflexion (0 degrees), 0-5 degrees of valgus, and 5-10 degrees of external rotation
. 5 degrees of dorsiflexion, neutral coronal alignment, and internal rotation matching the contralateral side
. Neutral dorsiflexion (0 degrees), 5 degrees of varus, and 0 degrees of rotation
. 5 degrees of plantarflexion, neutral coronal alignment, and 5-10 degrees of internal rotation

Correct Answer & Explanation

. Neutral dorsiflexion (0 degrees), 0-5 degrees of valgus, and 5-10 degrees of external rotation

Explanation

The optimal position for an ankle arthrodesis is neutral dorsiflexion (0 degrees), slight valgus (0-5 degrees), and slight external rotation (5-10 degrees) matching the contralateral side. This maximizes forward progression during stance phase and minimizes stress on the midfoot.

Question 60

Topic: Physiology & Rehabilitation

What is the ideal targeted position for an arthrodesis of the first metatarsophalangeal (MTP) joint to optimize postoperative gait?

. Neutral valgus and 20 degrees dorsiflexion
. 10 to 15 degrees valgus and 10 to 15 degrees dorsiflexion relative to the floor
. 20 degrees valgus and neutral dorsiflexion
. 5 degrees varus and 5 degrees plantarflexion
. Neutral valgus and neutral dorsiflexion

Correct Answer & Explanation

. 10 to 15 degrees valgus and 10 to 15 degrees dorsiflexion relative to the floor

Explanation

The optimal position for a first MTP arthrodesis is 10-15 degrees of valgus (to parallel the lesser toes) and 10-15 degrees of dorsiflexion relative to the floor. This allows for normal push-off during the gait cycle and accommodates standard footwear.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page