Explain Human Musculoskeletal System Quiz

1. On gait of your patient you note that he leans toward left side when he walks, when he is asked to stand on right leg, his body tilts to the left side(+Trendelenburg sign). Which muscles, nerve on which side is most likely involved?

Quadriceps femoris muscle and femoral nerve on the left side

*He likely has weakness of Gluteus Medius and Minimus on Right side(Contralateral to the site that drops and ipsilateral to the side he stands), but they are more likely to ask about nerve that innervates those and could result in these manifestations and that is SUPERIOR gluteal nerve.(Remember Medium size is Superior to Minimal size :P)-Superior gluteal nerve comes from L4-S1.*When he leans toward unaffected leg side during walking =Gluteus Medius Limp/Positive Trendelenburg sign .*Contrast this with Inferior gluteal nerve damage, patient will have trouble walking up the stairs and rising from seated position, as this nerve innervates Gluteus Maximus which is responsible for extenson of the thigh at the hip and external rotation of thigh.

Tibialis anterior muscle and peroneal nerve on the left side

Sartorius muscle and obturator nerve on the right side

The correct answer involves the gluteus medius and minimus muscles on the right side along with the superior gluteal nerve. The other incorrect options do not align with the symptoms described in the question.

Explanation

The correct answer involves the gluteus medius and minimus muscles on the right side along with the superior gluteal nerve. The other incorrect options do not align with the symptoms described in the question.

2. Which muscle movements are responsible for patient's trouble rising from the sitting position and climbing stairs, and which nerve could have been damaged?

*Gluteus Maximus is responsible for Extension of the thigh at hip and External rotation of thigh, it is innervated by INFERIOR gluteal nerve(L5-S1)*Remember :MAX broke up with his EX because she was INFERIOR to him.

Hamstrings responsible for Flexion of hip and knee, innervated by Sciatic nerve(L4-S3)

Quadriceps Femoris responsible for Flexion of hip and Extension of knee, innervated by Femoral nerve(L2-L4)

Tibialis Anterior responsible for Dorsiflexion and inversion of foot, innervated by Deep fibular nerve(L4-S1)

Multiple muscles and nerves are involved in different movements and actions of the body. In this case, the patient's trouble rising from sitting position and climbing stairs can be attributed to the Gluteus Maximus muscle and the Inferior Gluteal nerve being responsible for specific movements and functions.

Explanation

Multiple muscles and nerves are involved in different movements and actions of the body. In this case, the patient's trouble rising from sitting position and climbing stairs can be attributed to the Gluteus Maximus muscle and the Inferior Gluteal nerve being responsible for specific movements and functions.

3. Which muscles are responsible for increasing intra-abdominal and intra-thoracic pressure when performing the Valsava maneuver to promote vagal stimulation?

INTERNAL INTERCOSTAL muscles

EXTERNAL OBLIQUE muscles

*RECTUS ABDOMINIS muscles play the largest role in development of increased pressure in this region with valsava manuever.(No BS uw wants you to know that :))*If vagal stimulation fails you should give adenosine to patient with Paroxysmal SVT.

DIAPHRAGM muscle

When performing the Valsava maneuver, the RECTUS ABDOMINIS muscles play the biggest role in increasing pressure in the intra-abdominal and intra-thoracic regions. The DIAPHRAGM muscle primarily aids in respiration, while the INTERNAL INTERCOSTAL and EXTERNAL OBLIQUE muscles are not as directly involved in this specific action.

Explanation

When performing the Valsava maneuver, the RECTUS ABDOMINIS muscles play the biggest role in increasing pressure in the intra-abdominal and intra-thoracic regions. The DIAPHRAGM muscle primarily aids in respiration, while the INTERNAL INTERCOSTAL and EXTERNAL OBLIQUE muscles are not as directly involved in this specific action.

4. What is the likely cause of a patient being unable to aDDuct the thigh after pelvic surgery with lymph node dissection?

Femoral nerve damage (L2-L4)

**Obturator nerve damage(L2-L4).(anterior branch supplies GPA-Gracilis,Pectineus,Adductor Longus and Brevis, posterior branch innervates obturator Externus and adductor magnus), very characteristically with Obturator nerve damage we see Loss of sensation over MEDIAL thigh, note obturator nerve is frequently damaged with ANTERIOR hip dislocations.*If Thigh FLEXION and Leg Extension were compromised then you would have thought about FEMORAL nerve damage(L2-L4)-Femoral nerve innervates anterior thigh muscles-Quadriceps(leg extention),Sartorius,Pectineus(Accessory flexors of the hip), Sensory deficit would involve Anterior Thigh and Medial Leg.

Tibial nerve damage (L4-S3)

Sciatic nerve damage (L4-S3)

Obturator nerve damage leads to the inability to aDDuct the thigh and loss of sensation over the medial thigh.

Explanation

Obturator nerve damage leads to the inability to aDDuct the thigh and loss of sensation over the medial thigh.

5. Guy who spends a lot of time on his knees (like a roofer, plumber, carpet layer) complains of pain in the knee region/trouble flexing the knee. Symptoms get better with rest. On physical exam you note fluctuant edema over lower pole of the patella on the affected knee, along with swelling, redness, tenderness to palpation, erythema, and crepitance in the affected region. Which bursa is most likely involved?

Suprapatellar bursa

Infrapatellar bursa

Popliteal bursa

*Prepatellar bursa diminish friction and ensure maximal movement at the knee,chronic trauma due to excessive kneeling can cause prepatellar bursitis>"Housemaid's knee"<Uw not just me lol.

Chronic trauma due to excessive kneeling can cause prepatellar bursitis, also known as 'Housemaid's knee'. The prepatellar bursa diminishes friction and ensures maximal movement at the knee. The symptoms mentioned in the question are characteristic of prepatellar bursitis.

Explanation

Chronic trauma due to excessive kneeling can cause prepatellar bursitis, also known as 'Housemaid's knee'. The prepatellar bursa diminishes friction and ensures maximal movement at the knee. The symptoms mentioned in the question are characteristic of prepatellar bursitis.

6. The patellar ligament spans from the patella to the tibial tuberosity and is a continuation of which tendon?

*Quadriceps femoris tendon.*Quadriceps femoris muscles include vastus medialis,lateralis,intermedius and rectus femoris, all quadriceps muscles are powerful extensors while rectus femoris is also a flexor.*Damage to patellar ligament could>Difficulty with leg extension.

Achilles tendon

Hamstring tendon

Biceps femoris tendon

The patellar ligament is actually a continuation of the Quadriceps femoris tendon, which includes vastus medialis, lateralis, intermedius, and rectus femoris muscles. These muscles are powerful extensors, with rectus femoris also acting as a flexor. Damage to the patellar ligament may result in difficulty with leg extension.

Explanation

The patellar ligament is actually a continuation of the Quadriceps femoris tendon, which includes vastus medialis, lateralis, intermedius, and rectus femoris muscles. These muscles are powerful extensors, with rectus femoris also acting as a flexor. Damage to the patellar ligament may result in difficulty with leg extension.

7. What does PCL prevent?

PCL prevents LATERAL displacement of femur relative to tibia when the knee is flexed.

PCL prevents POSTERIOR displacement of femur relative to tibia when the knee is flexed.

*PCL prevents ANTERIOR displacement of femur relative to tibia when the knee is flexed.*Know:PCL tear produces POSTERIOR drawer sign(Posterior gliding of tibia when bending knee at 90 angle)*Contrast this with ACL tear where you have Anterior displacement of TIBIA relative to femur, ACL tear gives us ANTERIOR drawer sign(Bending knee at 90 angles results in anterior gliding of tibia, if test was performed at 30 angle than it is lacham test)*uw wants you to know that ACL connects lateral femoral condyle to anteromedial tibial head.*Vignette would often describe athlete with forceful blow to lateral knee in injuries of ACL (Can give damage to MCL and Medial meniscus too)Check pic, remember Anterior and Posterior refer to Attachement to Tibia(Believe me easiset way to not fuck these up_)

PCL prevents ROTATIONAL displacement of femur relative to tibia when the knee is flexed.

The PCL prevents anterior displacement of the femur relative to the tibia when the knee is flexed. This is important for maintaining stability in the knee joint.

Explanation

The PCL prevents anterior displacement of the femur relative to the tibia when the knee is flexed. This is important for maintaining stability in the knee joint.

8. Why does a subcapsular femoral head fracture could lead to avascular (aseptic) necrosis while a peritrochanteric fracture would not?

*Because Peritrochanteric fracture is Extracapsular and doesn't compromise blood flow, while Subcapsular fracture does damage retinacular ateries of Medial femoral circumflex artery(Makes largest contribution to supplying femoral head and neck), vignette would typically describe older female with osteoporosis who fell down and now has terrible pain, damage to MFCA can lead to avascular necrosis of femoral head, Avascular necrosis itself can predispose to OsteoARTHRITIS,Fracture.*Avascular necrosis affects bone and marrow, presents with pain and can be due to Corticosteroids,Sickle cell disease(vasoocclusive crisis n bone of hands and feet which presents as dactylitis),ALCOHOLISM, Caisson'/decompression disease(Vignette would mention Diver , mechanism of avascular necrosis here is creation of Gas -Nitrogen emboli lodging into vessel>Aseptic necrosis)*Legg-calve- perthes disease(idiopathic)- childhood condition that affects the hip, usually femoral head looses blood supply, key here is that this condition is common in childhood.*They love to ask you about association of Gauchers disease (Autosomal reccessive lack of B-glucocerebrosidase, characterized by macrophages with crumpled tissue paper appearance) with avascular necrosis of femur leading to erlenmeyer flask deformity*Slipped capital femoral epiphysis can cause avascular necrosis and can present with pain in groin region that radiates to sensory distribution of obturator nerve(Medial thigh), here we basically have a fracture through the growth plate (physis), which results in slippage of the overlying end of the femur (epiphysis). Normally, the head of the femur, called the capital, should sit squarely on the femoral neck. Abnormal movement along the growth plate results in the slip. The femoral epiphysis remains in the acetabulum (hip socket), while the metaphysis (end of the femur) moves in an anterior direction with external rotation, condition often involves both lower extremities.*Note Superior and inferior gluteal arteries and lateral/medial collateral circumflex arteries contribute to trochanteric anastomosis that supplies head and neck region of the femur.(MCL is most important though)

Because avascular necrosis is a common complication of both subcapsular and peritrochanteric fractures, but the underlying mechanisms are distinct.

Because subcapsular femoral head fracture occurs predominantly in males, whereas peritrochanteric fracture occurs predominantly in females.

Because peritrochanteric fracture involves more severe trauma compared to subcapsular fracture, leading to different outcomes.

A peritrochanteric fracture is extracapsular and does not affect the blood flow to the femoral head, while a subcapsular fracture damages the critical blood supply from the medial femoral circumflex artery, predisposing to avascular necrosis.

Explanation

A peritrochanteric fracture is extracapsular and does not affect the blood flow to the femoral head, while a subcapsular fracture damages the critical blood supply from the medial femoral circumflex artery, predisposing to avascular necrosis.

9. Which muscle and nerve are involved when abnormal prominence of the inferior scapular angle is observed on one side when a patient pushes against the wall with both hands?

Trapezius paralysis due to damage to the Spinal Accessory nerve (CN XI) causes scapular winging.

Deltoid muscle strain due to damage to the Axillary nerve leads to scapular winging.

*Serratus anterior paralysis due to damage to Long thoracic nerve(C5-C7) produces characteristic winged scapula.*Serratus anterior fixes scapula against posterior chest wall and rotates the scapula to allow aBduction of the arm over head.*Patient would present with difficulty lifting,pushing and pulling heavy items.*NOTE:Long thoracic nerve can be damaged in Axilla/Lateral Thorax and they love to ask you about artery that most likely was injured too-LATERAL thoracic ARTERY can be damaged here too.

Pectoralis major rupture due to damage to the Medial pectoral nerve results in scapular winging.

10. Which muscle is most likely responsible for a patient's inability to adduct/extend the humerus if it is due to damage to the thoracodorsal nerve?

*Lattisimus dorsi muscle is innervated by thoracodorsal nerve and is responsible for adduction and extension humerus.No bs Uw has it :)*Thoracodorsal nerve comes from posterior cord.

Teres major muscle

Deltoid muscle

Pectoralis major muscle

The latissimus dorsi muscle is innervated by the thoracodorsal nerve, which is responsible for adduction and extension of the humerus.

Explanation

The latissimus dorsi muscle is innervated by the thoracodorsal nerve, which is responsible for adduction and extension of the humerus.

11. What is an important fact to know about the teres major muscle?

*That teres major is NOT part of rotator cuff muscles.*Teres major is innervated by Subscapular nerve, this muscle Medially rotates the arm and aDDucts it.*Contrast this with Teres Minor which is innervated by axillary nerve and serves to aDDuct and laterally rotate the arm.

Teres major is a part of the rotator cuff muscles.

Teres major is innervated by the axillary nerve.

Teres major functions to laterally rotate the arm.

Teres major is often confused with teres minor, but they have different functions and innervation. It is important to know that teres major is not part of the rotator cuff muscles and is innervated by the Subscapular nerve.

Explanation

Teres major is often confused with teres minor, but they have different functions and innervation. It is important to know that teres major is not part of the rotator cuff muscles and is innervated by the Subscapular nerve.

12. What is the function of the Rhomboid major muscle?

*Draws the scapula medially at its border.*It is innervated by Dorsal scapular nerve<Uw wants you to know that don't get mad at me :P

Provides flexion of the elbow joint.

Moves the shoulder joint in multiple directions.

Assists in breathing by expanding the chest cavity.

The Rhomboid major muscle specifically functions to draw the scapula medially at its border, which helps with movements of the shoulder blade. It is innervated by the Dorsal scapular nerve, responsible for its motor function.

Explanation

The Rhomboid major muscle specifically functions to draw the scapula medially at its border, which helps with movements of the shoulder blade. It is innervated by the Dorsal scapular nerve, responsible for its motor function.

13. Which sensory deficit is most likely present in a patient who presents with Foot in Everted, Dorsiflexed position (Calcaneovagocavus position)?

MEDIAL aspect of the foot, nerve most likely damaged is sural nerve.

DORSAL surface of the foot, nerve most likely damaged is peroneal nerve.

*PLANTAR surface of the foot, nerve most likely damaged is tibial nerve.*Patient can't plantar flex(thus is stuck in dorsiflexed position) as this nerve innervates gastrocnemius,soleus,plantaris muscles(Which would normally do the plantar flexion)*Patient can't INVERT the foot(Thus foot is stuck in Everted position) as tibial nerve supplies Tibialis posterior for that movement.*Medial and plantar branches of tibial nerve supply distal part of plantar surface of the foot.*Extrinsic digital FLEXORS are also innervated by Tibial nerve(Uw wants you to know that :P)

HEEL of the foot, nerve most likely damaged is posterior tibial nerve.

The correct answer can be determined by understanding the specific muscles and movements associated with the tibial nerve innervation, which are affected in the described foot position.

Explanation

The correct answer can be determined by understanding the specific muscles and movements associated with the tibial nerve innervation, which are affected in the described foot position.

14. Cutaneous innervation of forearm?

Radial

Musculocutaneous

Median

*Ulnar Medial*MUSCULOCUTANEOUS LATERAL<KNOW THAT,don't write median nerve.

The correct cutaneous innervation of the forearm includes the ulnar nerve for the medial side and the musculocutaneous nerve for the lateral side. Radial and median nerves do not provide cutaneous innervation to the forearm.

Explanation

The correct cutaneous innervation of the forearm includes the ulnar nerve for the medial side and the musculocutaneous nerve for the lateral side. Radial and median nerves do not provide cutaneous innervation to the forearm.

15. Patient with fracture of the midshaft of the humerus, can't extend his wrist, which nerve/artery was most likely damaged?

Axillary nerve and Brachial artery

Ulnar nerve and Brachial artery

*At midshaft of humerus you can damage Radial nerve in radial groove(Hence the wrist drop)and DEEP brachial artery(Key word is DEEP, and yes they will make you choose between brachial artery and DEEP brachial artery)*Deep brachial artery branches from Brachial artery near teres MAJOR and passes posteriorly along the humerus with close association with radial nerve.*Don't confuse this midshaft of humerus with SURGICAL neck of humerus, where you are likely to damage Axillary nerve(Deltoid paralysis,over time atrophy of shoulder),Anterior circumflex humeral artery(branch of Axillary artery) passes anterior to surgical neck of the humerus and can be damaged.**Also note that Brachial artery itself is a branch of axillary artery and courses anteromedially in the arm runs in bicipital groove and gives off ulnar and radial branches as it enters forearm, associate damage of brachial artery with SUPRAcondylar fracture of humerus.

Median nerve and Radial artery

At midshaft of humerus, the most likely nerve to be damaged is Radial nerve which leads to wrist drop, and the most likely artery to be damaged is DEEP brachial artery. Do not confuse it with other possible nerve and artery combinations.

Explanation

At midshaft of humerus, the most likely nerve to be damaged is Radial nerve which leads to wrist drop, and the most likely artery to be damaged is DEEP brachial artery. Do not confuse it with other possible nerve and artery combinations.

16. Why is the Medial Femoral condyle on femoral head the most common site of AVN?

*Because it is watershed area between Medial Circumflex Femoral Artery(Retinacular branches) and branch of Obturator artery.

Because it is a non-weight bearing area of the femur.

As a result of direct trauma to the femoral head.

Due to poor blood supply from the Femoral artery.

Avascular necrosis (AVN) commonly affects the Medial Femoral condyle due to its vulnerable location at the watershed area between the Medial Circumflex Femoral Artery and a branch of the Obturator artery, leading to compromised blood supply.

Explanation

Avascular necrosis (AVN) commonly affects the Medial Femoral condyle due to its vulnerable location at the watershed area between the Medial Circumflex Femoral Artery and a branch of the Obturator artery, leading to compromised blood supply.

17. A baby holds her hand in a pronated position after her brother pulled her by the hand when he was trying to stop her from running into the street. She experiences pain with motion of her right elbow and there is no visible edema. What is the likely diagnosis?

*Subluxation of radial head.

Fracture of the radial head

Sprained wrist

Dislocated shoulder

In this scenario, the baby's symptoms of holding her hand in a pronated position after trauma to the arm, along with pain with motion of the elbow, point towards a subluxation of the radial head. This condition is commonly seen in children after a sudden pull on the arm. Fracture of the radial head, sprained wrist, and dislocated shoulder are less likely based on the given information.

Explanation

In this scenario, the baby's symptoms of holding her hand in a pronated position after trauma to the arm, along with pain with motion of the elbow, point towards a subluxation of the radial head. This condition is commonly seen in children after a sudden pull on the arm. Fracture of the radial head, sprained wrist, and dislocated shoulder are less likely based on the given information.

18. Pain/'pop' is elicited on internal rotation of the knee. Where is the patient's injury?

Posterior cruciate ligament (PCL)

*Lateral Meniscus produces these findings on McMurray's test, with INTERNAL rotation.(remember:IINTERNs are always LATE)*If same signs were found but on External rotation then most likely damaged structure would be Medial meniscus.*Medial meniscus-External rotation(ME)

Anterior cruciate ligament (ACL)

Patellar tendon

Injuries to the ACL, PCL, and patellar tendon typically present with different symptoms and mechanisms of injury compared to medial or lateral meniscus injuries.

Explanation

Injuries to the ACL, PCL, and patellar tendon typically present with different symptoms and mechanisms of injury compared to medial or lateral meniscus injuries.

19. Which ligament is most likely torn if a patient has abnormal passive adduction (laxity on application of varus stress-Medial force) or lateral tibial space widening when a varus force is applied?

MCL

ACL

*LCL is most likely torn.*i see VA(e)Ry Large Legs on those ADD s.(VARus stress,LcL,ADDuction)*LCL can be damaged when you fall on medial side of the knee(Varus stress)

PCL

LCL can be damaged when you fall on the medial side of the knee (Varus stress), resulting in abnormal passive adduction or lateral tibial space widening.

Explanation

LCL can be damaged when you fall on the medial side of the knee (Varus stress), resulting in abnormal passive adduction or lateral tibial space widening.

20. When you do passive abduction with the patient's leg in the extended position (or at 30 degrees), on applying Valgus force (lateral), you note medial space widening of the tibia. Which ligament is likely injured?

*MCL was likely injured.*MCL injury is common with lateral stress(VaLgus) in footbal players.*Mean people are always LATE and VuLgar.*Valgus injury often results in unhappy triad:MCL,ACL,Lateral meniscus.

LCL was likely injured.

ACL was likely injured.

PCL was likely injured.

MCL injury is common with lateral stress (valgus) in football players. Valgus injury often results in unhappy triad: MCL, ACL, lateral meniscus.

Explanation

MCL injury is common with lateral stress (valgus) in football players. Valgus injury often results in unhappy triad: MCL, ACL, lateral meniscus.

21. A patient who cannot move his shoulder after a traumatic accident has likely injured nerves at what spinal levels?

C8-T1

*C5-6*Remember that Rotator cuff muscles are involved in Movement of Shoulder.*Supraspinatus is MC rotator cuff injury(muscle is innervated by SUPRAscapular nerve), thus patient won't be able to abduct arm(first 15 degrees) if they somehow get over these first 15 angles(like helping it with second hand), then they can abduct just fine if DELTOID muscle(Innervated by axillary nerve) is intact.(Note deltoid is NOT rotator cuff muscle)*Also do not confuse SUPraspinatus with another Rotator cuff muscle-SUBscapualris(innervated by sup/inf subscapular nerves)which functions to ADDuct and MEDIALLY rotate the arm, contrast this with another rotator cuff muscle Teres MINOR(inneravated by AXILLARY nerve) which also adducts but LATERALLY rotates the arm.(to not mess up teres minor and Subscapularis functions: MED students often eat at SUBway while MINeRs are often LATE, but remember that they both ADDuct the arm)*Damage to Suprascapular nerve can result in defect of Lateral rotation because suprascapular nerve innervates INFRAspinatus.(These defect is commonly seen in pitchers)

L3-L4

T5-T6

Injuries at C5-6 levels typically result in shoulder movement deficits due to involvement of the suprascapular nerve, which innervates the supraspinatus muscle responsible for shoulder abduction. The incorrect options do not align with the common nerve injuries associated with shoulder movement impairments.

Explanation

Injuries at C5-6 levels typically result in shoulder movement deficits due to involvement of the suprascapular nerve, which innervates the supraspinatus muscle responsible for shoulder abduction. The incorrect options do not align with the common nerve injuries associated with shoulder movement impairments.

22. What structures are commonly damaged in an injury involving MCL tear due to Valgus stress (lateral) in the knee?

PCL, Medial Meniscus

Patellar Tendon, Quadriceps Tendon

*ACL,Lateral Meniscus.-Unhappy triad, patient would present with acute knee pain+Signs of joint instability/injury..Note that they will likely describe patient with MCL,ACL damage(like pain on external rotation of tibia during Mcmurray test and anterior gliding of tibia in relative to femur during Anterior drawer sign respectively)and ask you side from which force was most likely applied-that is LATERAL force(Valgus force).*LCL injury however is MORE COMMON.(On Mcmurray test there would be pain/popping on INTERNAL rotation of the tibia)

LCL, Posterior Cruciate Ligament

In this specific injury scenario, known as the unhappy triad, the ACL and Lateral Meniscus are commonly damaged along with the MCL. It is important to recognize the pattern of injuries associated with specific mechanisms to provide accurate treatment and management.

Explanation

In this specific injury scenario, known as the unhappy triad, the ACL and Lateral Meniscus are commonly damaged along with the MCL. It is important to recognize the pattern of injuries associated with specific mechanisms to provide accurate treatment and management.

23. When you are clapping your hands with your elbows at your sides, which muscles are involved in bringing your hands together/separating them apart?

*Subscapularis will bring your arms together (remember MED students often eat at SUBway-Subscapularis Medially rotates the arm)*Teres MINOR/INFRApsinatus will bring them apart.(teres MInor and Infraspinatus are involved in Lateral rotation)-People who are LATE are always INFERIOR to those who pay attention to MINOR details.

Biceps brachii and deltoid

Extensor carpi radialis longus and flexor carpi radialis

Pectoralis major and trapezius

Subscapularis, Teres Minor, and Infraspinatus are the primary muscles involved in bringing the hands together/separating them apart specifically in the scenario described in the question.

Explanation

Subscapularis, Teres Minor, and Infraspinatus are the primary muscles involved in bringing the hands together/separating them apart specifically in the scenario described in the question.

24. Why does a tennis player present with chronic pain in the lateral side of the elbow?

The pain is caused by a direct impact to the lateral side of the elbow during a match.

The pain is a result of poor technique while serving.

The pain is due to overuse of flexors in the arm.

*Due to repetitive use of EXTENSORS-like Flexor carpi Radialis(due to Backhand shots), he developed Lateral Epicondylitis.*However note that Both(medial,lateral) overuse injuries can be idiopathic.

The correct answer explains how the repetitive use of extensors leads to Lateral Epicondylitis in tennis players. The incorrect answers propose other potential causes of the pain in the lateral side of the elbow, but they do not align with the typical mechanism of injury in this scenario.

Explanation

The correct answer explains how the repetitive use of extensors leads to Lateral Epicondylitis in tennis players. The incorrect answers propose other potential causes of the pain in the lateral side of the elbow, but they do not align with the typical mechanism of injury in this scenario.