Question

multiple choice question
a 30 - year - old runner presents with sudden onset sharp pain in the back of his thigh during a sprint. he recalls feeling a \pop\ at the time of injury. on examination, there is tenderness and swelling over the posterior thigh, with a palpable defect in the muscle belly. passive knee extension is painful, and there is weakness during resisted knee flexion. which of the following is the most likely diagnosis?
please select your answer...
a hamstring strain
b quadriceps tendon rupture
c achilles tendon rupture
d patellar tendon rupture

Explanation:

• Hamstring strain: The hamstrings are located at the posterior thigh. A sudden - onset injury (like during a sprint) with a "pop" sound (indicative of muscle - tendon unit injury), tenderness, swelling, a palpable defect (suggesting muscle fiber disruption), pain with passive knee extension (which stretches the hamstrings), and weakness during resisted knee flexion (as the hamstrings are the main knee - flexing muscles) are all consistent with a hamstring strain.
• Quadriceps tendon rupture: The quadriceps is on the anterior thigh. Rupture would affect knee extension rather than flexion.
• Achilles tendon rupture: Occurs at the back of the lower leg (calf - heel area), not the thigh.
• Patellar tendon rupture: Affects the connection between the patella and the tibia, and is related to knee - extensor function issues rather than the symptoms described here.

Answer:

A. Hamstring strain