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1. The patellar tendon reflex. 2. A colloquial term for a reaction or response to a stimulus without prudent or thoughtful consideration.

kneeling chair

An ergonomically designed chair in which most of the body weight is supported on the buttocks, but some of it is borne on the knees and shins. It creates a greater angle between the thigh and torso than a regular sitting chair to more closely approximate standing and promote maintenance of the lumbar lordosis. It is designed to alleviate or prevent low back pain.

Kniest dysplasia

((k)nēst) [Wilhelm Kniest, 20th-cent. Ger. pediatrician] An autosomal-dominant collagen disorder that causes dwarfism. Findings include a short trunk, prominent and stiff joints, flattened face, eye abnormalities, deafness, inguinal hernias, hip dislocation, cleft palate, and talipes equinovarus. Patients develop severe dorsal kyphosis or kyphoscoliosis and lumbar lordosis. SYN: Swiss cheese cartilage syndrome.


(nīf) A tool for cutting or piercing, typically having a long blade attached to a handle.

diamond k. A knife with a very thin, hard diamond edge, used to incise specimens or to perform delicate operations, e.g., on facial skin or the eyes.

electric k. A knife that functions by a high-frequency cutting current.

gamma k. A radiosurgical device that uses gamma rays from radioactive cobalt to cut or excise diseased tissue, esp. in the brain. The radioactive energy emitted by the knife is focused stereotactically to limit injury to healthy tissue.

gold k. A contra-angle knife used to trim a gold filling in a tooth.

guarded k. A knife whose sharp point or edge is ensheathed rather than exposed.

hot k. An electric, ultrasonic, or radiation- powered scalpel that cuts and coagulates tissues simultaneously

Humby k. A knife used in skin grafting for shaving off a layer of skin.

periodontal k. A surgical knife with a scaler-shaped blade whose entire perimeter is a cutting edge. It is used in gingivectomy and other periodontal surgery.

plasma k. Plasma scalpel.

plaster k. A stout knife used for cutting and trimming plaster study models in dental practice.

rocker k. An assistive technology device for those with limited upper-extremity function. It allows one-handed stabilization and cutting of food.


[AS. cnyttan, to make knots] The process of healing by uniting pieces of a fractured bone.


(nŏb) [ME. knobbe] A protuberance on a surface or extremity; a mass or nodule.



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