A common example is the standard patellar reflex or knee-jerk response.Deep tendon reflex also usually refers to this sense.
This mechanism, which occurs in two major stages, serves several beneficial purposes, one of which is to prevent injury. The contraction occurs because the quick tapping on the tendon results in a stretch of the muscle spindles running parallel to the muscle fibers.
Deep tendon reflexes are responses to muscle stretch. Test deep tendon reflexes. Reflexes elicited by application of a stretch stimulus to either tendons or periosteum, or occasionally to bones, joints, fascia, or aponeurotic structures are usually referred to as muscle stretch or deep tendon reflexes. This video on Deep Tendon Reflexes (DTRs) has been provided by: Stanford Medicine 25. A firm tap on the tendon draws the patella down, stretching the quadriceps and provoking reflex contraction. Lower motor neuron lesions (eg affecting the anterior horn cell, spinal root or peripheral nerve) depress reflexes: upper motor neuron lesions increase the reflexes. Deep tendon reflexes are actually muscle stretch reflexes mediated through neuromuscular spindles.
Lower motor neuron lesions (eg affecting the anterior horn cell, spinal root or peripheral nerve) depress reflexes: upper motor neuron lesions increase the reflexes. They are particularly useful if there are asymmetric findings or if they occur in the context of other changes; isolated hyper or hypo reflexic … This article will focus on the “deep tendon reflexes” which are more appropriately named — and will be referred to herein — as muscle stretch reflexes (MSR). This is an example of a reflex, which is an involuntary muscular response elicited by the rubber hammer tapping the associated tendon. A stretch reflex, also referred to as a deep tendon reflex or myotatic stretch reflex, is a physical response to the extension of a muscle.
Deep Tendon Reflexes: Check the deep tendon reflexes using impulses from a reflex hammer to stretch the muscle and tendon. It is test of the integrity of the afferent and efferent pathways, and of the excitability of anterior horn […] Although these reflexes are often called deep tendon reflexes, this name is a misnomer because tendons have little to do with the response, other than being responsible for mechanically transmitting the sudden stretch from the reflex hammer to the muscle spindle.
Charles D. Donohoe, in Pain Management, 2007. Deep Tendon (muscle stretch) Reflexes Evaluates afferent nerves, synaptic connections within the spinal cord, motor nerves, and descending motor pathways. The muscle stretch reflex is the most basic reflex pathway in the body and as such, understanding this allows understanding of more complex reflexes. Deep Tendon (muscle stretch) Reflexes Evaluates afferent nerves, synaptic connections within the spinal cord, motor nerves, and descending motor pathways. They are the one facet of the clinical examination that is objective (Table 4-9). Understanding deep tendon reflexes A quick tap on a tendon, such as the patellar tendon below the knee cap, will elicit a reflexive contraction of the quadriceps muscle. The reflex exam is fundamental to the neurological exam and important to locating upper versus lower motor neuron lesions. Strike your finger and feel for the contraction inward. There are five deep tendon reflexes and a number of superficial and visceral reflexes covered here. If the examiner places one hand over the muscle, and with the other hand taps the patellar tendon just below the patella, she can palpate the contraction as well as observe the rapidity and range of … The deep tendon reflexes (and the abdominal reflexes) are important physical signs which have a special place in neurological diagnosis, particularly in early disease when they alone may be abnormal. To test the biceps reflex, place your finger on the biceps tendon in the fold of the elbow. Deep Tendon Reflex: If a tendon of a lightly stretched muscle is struck with a single sharp blow with a soft rubber/ clinical hammar, the muscle contracts briefly and briskly. Note that in day-to-day movement, tension in the muscles is not sufficient to activate the GTO’s deep tendon reflex. If the reflex is brisk, the contraction is strong and the amplitude of the movement is large. Lower motor neuron lesions (eg, affecting the anterior horn cell, spinal root, or peripheral nerve) depress reflexes; upper motor neuron lesions (ie, non–basal ganglia disorders anywhere above the anterior horn cell) increase reflexes.