The Queen Square Pattern Knee Hammer for effective elicitation of myotatic, plantar and abdominal responses with greater patient comfort The Queen Square Pattern Knee Hammer head is surmounted with a chrome-plated brass disc (approximately 50mm diameter) grooved to house the rubber collar. The weighted head and soft rubber collar is perfectly suited in provoking myotatic responses Flexible Nylon handle consists of a slender tapering handle. The tapered point is suited for eliciting plantar and abdominal responses.