This clinical photograph demonstrates the proper technique for eliciting the patellar tendon reflex (knee jerk) in a sitting position, incorporating the Jendrassik maneuver. The patient is seated on an examination table with legs hanging freely and knees flexed at a 90-degree angle, ensuring the feet do not touch the floor to allow for unobstructed lower leg extension. Simultaneously, the patient performs the Jendrassik maneuver by interlocking their fingers and attempting to pull their hands apart, a reinforcement technique designed to facilitate deep tendon reflexes (DTR) by reducing conscious inhibition and increasing upper motor neuron activation. The examiner, standing to the patient's side, is seen using a neurological reflex hammer to strike the patellar tendon just below the patella. This procedure tests the L3-L4 spinal segments and the femoral nerve. The image serves as an educational guide for neurological physical examination, highlighting proper patient positioning, the use of reinforcement maneuvers, and the anatomical striking point for DTR assessment.

A clinical photograph demonstrating the kneeling technique for eliciting the Achilles tendon reflex (ankle jerk), which tests the S1-S2 nerve roots and the tibial nerve. The patient is positioned kneeling on an examination table with their shins supported by the table surface and their feet hanging freely over the edge. This position allows for optimal relaxation of the gastrocnemius-soleus complex. The examiner is shown performing two simultaneous actions: using one hand to apply gentle passive dorsiflexion to the plantar surface of the foot to place the Achilles tendon under slight tension, and using a standard reflex hammer in the other hand to strike the tendon just above its insertion on the calcaneus. This procedural image illustrates a standard method in a neurological physical examination to assess deep tendon reflexes and identify possible upper or lower motor neuron pathology.

This clinical photograph demonstrates the assessment of the patellar tendon reflex (knee-jerk) in a patient positioned supine. The patient's legs are arranged with the right leg crossed over the left, placing the uppermost knee in a flexed position that naturally stretches the quadriceps tendon. An examiner’s hand is visible, stabilizing the knee while using a reflex hammer with a circular rubber head to strike the patellar ligament just distal to the patella. This procedure is used to evaluate the L3-L4 spinal nerve roots and the integrity of the femoral nerve. The image illustrates a practical modification for eliciting deep tendon reflexes when a patient is in a semi-recumbent or supine position on an examination table, emphasizing proper limb positioning and strike location for clinical diagnostic purposes.