I'm now going to demonstrate the deep tendon reflexes. In doing the reflexes is important to position the patient. It's important to know the level that you're testing. And it's important to have the right tools in order to get the reflexes. We use a Queen Square hammer. We give this to all our incoming interns. I think it has a nice flex to it. And it's really a good tool to get the reflexes. Even though you can get it in other ways, we recommend this. I'm going to begin with the brachio-ridealis reflex. I'm going to tap on the tendon not so much on the muscle. And this is a C56 reflex. I'm also going to do the biceps reflex by putting my hand on the biceps tendon. And then I'm going to strike my thumb. And I will feel the contraction as well as perhaps see the muscle contract. I think one important caveat is that it's important to keep your eye glued on the muscle and not so much focused on the movement. Because if it's a very depressed reflex, all you might see is the contraction of the muscle. That will be C56 again for the biceps. I'll now do the triceps, which you could do many ways. If he's relaxed this way, I could just choose to leave his arm in the position it is. And I'm actually getting a good reflex in this fashion. So I probably wouldn't proceed further. But I could also suspend the arm like this, instruct the patient to lean on my hand as though leaning on a railing. And the measure of the hand being relaxed is that the forearm is loose. And then once again, strike the triceps tendon. And this is a C678 reflex, a higher level than the biceps 5.6. If people are hyper-reflexic, you can often elicit a finger-flexion reflex. It's only significant if it's present on one side and not on the other. The patient's hand is very relaxed and it's supported by his thigh. I'm simply inserting my finger in there and asking him to just relax and leave his fingers the way they are. I tap on my fingers and you can see the brisk movement of his fingers. This is a finger-flexion reflex. It's significance is only if it's absent on one side and present on the other. We're going to do the brachio-radialis reflex. It's important to tap on the tendon and not the muscle. And to look at the muscle for contraction rather than looking for the movement. So even though there's a nice brisk movement, you see the muscle contracting as well. I'm going to do the biceps reflex. I put my hand on the biceps tendon. And I tap on my thumb, keep my eyes glued on the muscle. Both these reflexes, the biceps and the brachio-radialis are C56. In the same position, I can also do the triceps reflex as the patient is nicely relaxed. I'm going to strike over the triceps tendon and look for the contraction of the triceps muscle. And I see a contraction, you might or might not see a movement of the arm. The ankle reflex in a patient who's seated like this can be a little tricky. And if it's not a very brisk reflex, you might conclude that it's not there. I would put make sure that the foot is loose. Put a little bit of tension on the muscle, but not too much. And then strike over the keel extendant. And I can both see a contraction and see the resultant movement. This is S1 level. This is a great example of how this hammer gives you a great advantage over a little tailor hammer. I'm now going to move up to the knee reflex. And again, with the patient sitting like this and very relaxed, it's quite easy to hit the patellar tendon and notice a nice brisk contraction of the quadriceps muscle. Again, be sure to expose the muscle you're looking at. Keep your eyes glued on the muscle. Don't worry about the movement, especially the vastest medialis, which is the last thing to go when you lose the knee reflex. The ankle reflex in a bedridden patient is a little more tricky and there's a couple ways you can do it. But it's easy to conclude that the reflex is not there when it actually is and your technique impeded you from getting it. One way to do it is to simply make a bar with your two fingers across the metatarsal heads and cock the foot up just a tad. Keep your eyes on the muscle. In this case, you can actually see a nice brisk contraction just by this. Yet another way to do it is if the patient is mobile and has fairly loose joints, you can outwardly rotate the hip, flex the knee, a tad. Again, put a little bit of tension on the tendon. Keep your eye glued on the muscle. Don't worry about the movement, the muscle is what we want to see. And we see a very nice contraction. This is again S1. Yet another way, which is useful in someone who doesn't relax very well, is to take the foot you're examining and cross the upper one-third of the foot you're testing over the lower one-third of the other foot. And the great beauty of this method is that if you get the position successfully, the patient cannot keep their foot taught. It winds up being a great position because they are unable to contract their foot. And now I put a little bit of tension there, eyes glued on the muscle. And we see a very nice contraction. This is the ankle reflex. It's S1. The preceding program is copyrighted by the Board of Trustees of the Leland Stanford Junior University. Please visit us at med.stanford.edu.