How the Anterior Drawer Test Evaluates Ankle Instability

The anterior drawer test is a hands-on clinical exam used to check whether the main ligament on the outside of your ankle has been torn or stretched. A clinician stabilizes your lower leg with one hand, cups the heel with the other, and pulls the foot forward. If the foot slides forward more than expected, the test is “positive,” suggesting damage to the anterior talofibular ligament (ATFL). The test has been a mainstay of ankle sprain assessment for decades, but its accuracy depends heavily on technique, timing, and who is performing it.

What the Test Is Actually Checking

The ATFL is a short, flat band of tissue that connects the outer ankle bone (the fibula) to the talus, the bone that sits on top of the heel. It is the most commonly injured ligament in ankle sprains, especially the inversion type where the foot rolls inward. The anterior drawer test pulls the talus forward relative to the tibia and fibula to see whether that ligament is intact enough to resist the movement.

Biomechanical studies confirm that the ATFL is the primary restraint against this forward shift. In one cadaver study, the ATFL bore roughly 65 to 80 percent of the total force resisting a 6-millimeter forward displacement of the talus when the ankle was slightly pointed downward.¹ Other ligaments on the inner side of the ankle contributed only small fractions of the restraining force. A separate robotic study found that cutting even just the upper portion of the ATFL produced a measurable increase in forward translation and internal rotation of the talus, especially when the ankle was in a toes-down position.²

How the Test Is Performed

You sit or lie down with your knee slightly bent so the calf muscles relax. The examiner wraps one hand around the front of your lower shin to hold it still, then cups the heel with the opposite hand. The examiner draws the heel and foot straight forward, feeling for how much the talus slides out from under the ankle joint. A positive result is either more sliding than normal or a soft, mushy endpoint instead of a firm stop.

Foot position matters more than most people realize. Biomechanical testing shows that the biggest difference in laxity between a normal ankle and one with a torn ATFL shows up when the foot is pointed slightly downward. With the ankle in 10 degrees of plantarflexion, laxity increased by about 76 percent after the ATFL was cut; at 20 degrees of plantarflexion, the increase reached roughly 90 percent.³ In contrast, when the ankle was pulled up into dorsiflexion, the change in laxity was much smaller. This is why most clinical guidelines recommend performing the test with the foot in a relaxed, slightly downward position rather than pulled up toward the shin.

There is a historical wrinkle here. Some of the original descriptions of the test from the 1960s actually recommended testing at a right angle (neutral or dorsiflexion), and one early description even noted that a positive test “usually becomes negative” when the ankle is plantarflexed.⁴ Other pioneers of the test observed the opposite. Biomechanical evidence has since settled the debate in favor of slight plantarflexion, but the conflicting original descriptions help explain why clinicians have performed the test differently from one another for decades.

Accuracy Numbers and What They Mean for You

No physical exam test is perfect, and the anterior drawer test is a good illustration of why. A systematic review pooling data from six studies found that the test had a sensitivity of about 54 percent and a specificity of about 87 percent.⁵ In plain terms, if your ATFL is actually torn, there is roughly a coin-flip chance the test will catch it. But if the test does come back positive, it is quite likely that there really is a tear.

Those numbers vary a lot depending on how the study was designed. One study that used an instrumented device to define specific millimeter cutoffs for a “positive” test found higher sensitivity (74 to 83 percent, depending on the cutoff), but specificity dropped to around 38 to 40 percent.⁶ Another study focused specifically on ATFL injuries reported sensitivity and specificity both around 80 to 81 percent.⁷ The spread across studies is wide enough that no single pair of numbers tells the whole story. What you can take from the literature is that a clearly positive anterior drawer test is a fairly reliable indicator of ligament damage, but a negative test does not rule a tear out.

A broader review that looked at multiple ankle exam maneuvers found that the anterior drawer test reported both high sensitivity and high specificity relative to other tests, though the exact figures varied with the population and reference standard used.⁸ In clinical practice, most experienced examiners treat the anterior drawer as one piece of a puzzle rather than a standalone verdict.

Timing Changes Everything

One of the least appreciated factors in the test’s accuracy is when it is performed. Right after an ankle sprain, swelling and pain cause guarding, which means your muscles involuntarily tighten to protect the joint. That guarding can mask the laxity the examiner is trying to feel. A study comparing acute and delayed examination found that the anterior drawer test had 100 percent specificity in the first few days after injury (meaning a positive result was very trustworthy) but only 21 percent sensitivity, meaning it missed most tears.⁹ When the same patients were re-examined later, after swelling had subsided, sensitivity jumped to 61 percent.

This is why some clinicians prefer to wait four to seven days before performing the test, once the acute inflammation has settled enough for the patient to relax the ankle. Others will still perform it acutely but pair it with other findings. In that same study, lateral swelling had 100 percent sensitivity in the acute setting and the presence of a bruise (hematoma) had high specificity, so combining visual signs with the drawer test can compensate for the test’s early limitations.¹⁰

The Examiner Problem

Perhaps the biggest practical weakness of the anterior drawer test is that different examiners can get different results on the same ankle. A review of the available evidence found that the test generally has good to excellent reliability when the same clinician repeats it, but relatively poor reliability when different clinicians examine the same patient.¹¹ Examiner experience and technique both influence the result.

This inter-examiner gap has been quantified. In one study, a junior examiner measured significantly less forward translation than a senior examiner when performing the traditional version of the test (about 3.3 mm versus 4.5 mm on the same ankles). The difference was large enough to change whether the test would be called positive or negative.¹² An experienced examiner applies force more confidently and is better at sensing the quality of the endpoint, both of which affect the outcome. This is worth keeping in mind if you are being examined in an urgent care or emergency setting where the examiner may perform ankle drawer tests infrequently.

A Modified Version Aimed at Better Consistency

Recognizing the inter-examiner reliability problem, researchers have developed a “supported” version of the anterior drawer test. In this variation, the patient’s lower leg is propped up on a support to keep the knee and ankle at consistent angles, and the examiner applies the force in a more standardized way. When the junior and senior examiners in the study mentioned above performed the supported version, the gap between their measurements nearly disappeared (4.6 mm versus 4.1 mm, with no statistically significant difference). For the junior examiner specifically, diagnostic accuracy improved substantially with the supported method: sensitivity rose from 40 to 80 percent, and specificity was 80 percent.¹³ This modified technique is not yet universally adopted, but it suggests that much of the test’s variability comes from inconsistent positioning rather than a fundamental flaw in the concept.

How It Compares to Imaging

Ultrasound, MRI, and stress X-rays can all assess the ATFL, and each has strengths the manual test lacks. Ultrasound, in particular, has shown impressive results. One study found that ultrasound had 100 percent sensitivity and specificity for distinguishing a normal ATFL from a torn or sprained one, compared to 81 percent sensitivity and 80 percent specificity for the anterior drawer test in the same patients.¹⁴ MRI provides a detailed picture of the ligament’s structure and can identify partial tears that manual testing would miss; in one series of patients with chronic ankle instability, MRI detected tears in every case that was later confirmed at surgery.¹⁵

Stress X-rays, where the drawer maneuver is performed while an X-ray is taken, offer a way to quantify exactly how many millimeters the talus shifts. However, a classic comparison study of 244 patients found that the anterior drawer sign on X-ray and the talar tilt test each caught injuries the other missed, and neither could replace the other.¹⁶ The two are considered complementary.

Instrumented ankle laxity testers, devices that apply a standardized force and measure displacement electronically, sound like the ideal solution. In practice, a systematic review found that while these devices produce reliable measurements, they have limited diagnostic accuracy for identifying chronic ankle instability, and different devices have produced conflicting results about whether mechanical laxity is actually present.¹⁷ A separate study found no significant correlation between measurements from two common ankle arthrometers and either stress radiography or the manual drawer test.¹⁸ So despite the appeal of objective numbers, instrumented testing has not replaced the manual exam or imaging.

Can the Test Predict Long-Term Problems?

A positive anterior drawer test after a fresh sprain naturally raises the question of whether you are headed for chronic ankle instability. The evidence here is sobering for anyone hoping for a simple answer. A study that followed patients from a first-time lateral ankle sprain found that combining the anterior drawer test with the talar tilt test, talar glide test, and plantarflexion range of motion correctly predicted who would develop chronic instability only about 69 percent of the time, with 64 percent sensitivity and 72 percent specificity.¹⁹ In other words, even when you stack multiple clinical tests together, predicting the future of an acutely sprained ankle remains difficult. Factors like rehabilitation adherence, neuromuscular control, and activity level all influence outcomes in ways a single physical exam cannot capture.

Tracking Healing With Ultrasound-Guided Drawer Testing

A more recent use of the anterior drawer concept is combining it with ultrasound to track how a torn ATFL heals over time. Instead of relying on feel, the examiner performs the drawer maneuver while an ultrasound probe images the gap between the talus and fibula. A study of patients with severe (grade III) lateral ankle sprains found that the measured gap during the drawer test was about 3.0 mm at baseline, stayed similar at one week (about 2.7 mm), then dropped significantly to about 1.0 mm by week three.²⁰ By week five, the gap was close to the unaffected side (roughly 1.3 mm versus 1.2 mm). This kind of serial monitoring could help clinicians decide when it is safe to return to sport, though the approach is still mostly used in research settings and specialized clinics rather than in routine care.

When the Test Does Not Apply Cleanly

Several situations can make the anterior drawer test misleading or hard to interpret. Patients with naturally hypermobile joints may have bilateral laxity that looks like a positive test even when no injury has occurred. This is why the uninjured ankle should always be tested for comparison. People with significant swelling, a recent fracture, or an open wound around the ankle may not tolerate the test, and the swelling itself can restrict movement enough to produce a false negative.

One biomechanical study offers a nuance worth noting: under strictly forward-backward loading without any weight on the joint, no single ligament dominated the restraining force.²¹ The ATFL’s dominance becomes clearest when the ankle is plantarflexed and when some rotational component is present, as tends to happen naturally during a manual test. But this means that a very carefully isolated, perfectly straight anterior pull in a neutral position could understate the ATFL’s contribution and reduce the test’s sensitivity. It is one more reason why technique and foot position matter.

Injuries to the calcaneofibular ligament (the ligament just behind the ATFL) or the deltoid ligament on the inner ankle can also affect how much the talus shifts forward, potentially confusing the picture. And in patients with chronic instability who have adapted their movement patterns over years, the test may be positive without the patient experiencing any symptoms of giving way. Mechanical laxity and functional instability do not always go hand in hand.

What Happens After a Positive Test

A positive anterior drawer test alone does not dictate treatment. Most isolated ATFL injuries, even complete tears, are managed with functional rehabilitation: a period of protection with a brace or walking boot, followed by progressive exercises to restore range of motion, strength, and balance. Imaging is typically reserved for cases where the injury does not improve as expected, where the clinical picture is complicated by possible fracture, or where surgery is being considered for chronic instability that has not responded to rehabilitation.

If you are told your anterior drawer test is positive after a sprained ankle, the practical meaning is that you likely have some degree of ATFL damage, but the grade of injury (stretch versus partial tear versus complete rupture) usually cannot be determined by the manual test alone. The test tells the clinician that the ligament is compromised and guides the initial management plan. If symptoms persist beyond the expected healing window, or if the ankle keeps giving way despite rehabilitation, that is when advanced imaging or surgical consultation typically enters the picture.