The patella deviates to the lateral side due to unopposed contraction of the vastus lateralis.
The lateral cutaneous nerve of thigh, a branch of lumbar plexus gets contribution from L1 and L2 segments of the spinal cord. It innervates the lateral aspect of thigh. It descends along the lateral border of the psoas major muscle and enters the thigh after passing deep to the fascia iliaca and the inguinal ligament. Sometimes the nerve is incorporated within the substance of the fascia iliaca and placed in a fibrous tunnel of the inguinal ligament. Irritation of this nerve in the fibrous tunnel produces pain along the lateral aspect of thigh. This is known as Meralgia parasthetica. Freeing the nerve from the fibrous tunnel will relieve the symptoms. While doing laproscopic surgery for inguinal hernia, accidental damage to the nerve in the “triangle of pain” (a non-anatomical triangle described by the laproscopic surgeons) can cause pain and tingling sensation in the area of its innervation.
The condition known as “foot drop” indicates that the muscles in the anterior compartment of the leg, that dorsiflex the foot at the ankle joint, have lost their nerve supply. The nerve supplying this compartment is the superficial fibular nerve, which is a branch of the common fibular nerve.
The valves in the perforating veins ensure unidirectional blood flow from the superficial veins to the deep veins. Following damage to the valves, the direction of blood flow is reversed resulting in engorgement of superficial veins.
The dorsalis pedis artery is the continuation of the anterior tibial artery distal to the extensor retinaculum. The dorsal midline of the foot is a routine location at which to evaluate the quality of blood flow by compressing the dorsalis pedis artery against the tarsal bones.
From the supraspinous fossa of scapula, the tendon of the supraspinatus muscle passes laterally under the acromion to be attached to the greater tubercle of humerus. Therefore, an injury to this tendon could cause pain during abduction of the arm. Note that the supraspinatus abducts the arm mainly in the initial stage of abduction. It is commonly involved in rotator cuff injury. The tendon is separated from the arch and the deltoid muscle by the subacromial bursa. Therefore, inflammation of this bursa (subacromial bursitis) also makes abduction of the arm painful.
Injury to the upper trunk of brachial plexus usually results from excessive separation of the neck and shoulder, which may be seen in violent stretching of an infant’s neck during delivery.
Injury to the lower part of brachial plexus is due to sudden upward pulling of the upper limb and compression of the lower trunk by a cervical rib.
Carpal tunnel syndrome is caused by the compression of the median nerve as it passes through the carpal tunnel in the wrist. This patient’s history is classic for this problem. As the median nerve innervates the thenar muscles in the hand, opposition of the thumb would be impaired or absent. All other movements listed can be produced by muscles in the forearm (abduction, flexion, and extension) or by muscles innervated by other nerves (adduction).
The posterior circumflex humeral artery is a branch of the third part of the axillary artery. It accompanies the axillary nerve through the quadrangular space. The artery contributes to the collateral blood supply around the shoulder. The artery and nerve are often damaged by fracture of the surgical neck of the humerus.
The serratus anterior muscle is responsible for holding the scapula against the posterior thoracic wall. Loss of function of this muscle causes the scapula to “wing,” or move away from the posterior thoracic wall. The serratus anterior muscle is innervated by the long thoracic nerve. This nerve passes through the axilla on the lateral thoracic wall, superficial to the serratus anterior muscle. Surgery in the axilla can damage this nerve
The inability to extend the fingers indicates an injury to the radial nerve.
The thoracodorsal nerve innervates the latissimus dorsi muscle. This muscle extends, medially rotates, and adducts the arm.
You Might Have Missed These Posts