This past August, my husband James fell from a ladder and twisted his left knee. He felt immediate pain and heard a “pop.” He has had two surgeries for a torn meniscus on the right knee in the past two years, and other knee surgeries dating back to 2005. His orthopedic surgeon got him in quickly for an appointment. An MRI (magnetic resonance imaging) showed a torn ACL.

Normally, a tear of that severity would result in surgery, but as a survivor of bone marrow cancer, he is not a good candidate for that. The surgeon feels that an ACL graft would not “take” on him. Instead, he ordered a brace and exercise; it is a “do what you can” situation. He has pain from it, and his walking is sometimes unstable, but he lives with it.

Although the ligament is a dense and strong structure, ACL injury is common, accounting for half of all knee injuries. In the U.S., about 200,000 people are diagnosed with a torn ACL annually. Also referred to as ACL sprains, ACL tears are very common among athletes. There are many studies ranging from those playing childhood sports to professional athletes. For example, in a 2016 study on torn ACL and ACL surgery states that there is no well-defined documentation of incidence in the general population.

Anatomy and function

The anterior cruciate ligament (ACL) is a band of thick connective tissue between the femur and the tibia, composed mainly of collagen bundles and a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. It is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the lateral and medial inferior genicular artery.

Like all ligaments, it has few blood vessels. A synovial fold where the terminal branches of the middle and inferior arteries form a network surrounds both the anterior and posterior cruciate ligaments (PCL), while parts of the ligaments themselves are wholly avascular. The ACL is an important structure in the knee joint, as the ligament basically functions as a piece of elastic, resisting anterior movement of the tibia relative to the femur and rotational loads. It serves to prevent hyperextension of the knee. But like any piece of elastic, it can only stretch so far.

The history of ACL goes back to the Smith Papyrus, an ancient Egyptian document dating to 1600 B.C., but it was believed to be a copy of a document created in 3000 B.C.

Hippocrates (460-370 B.C.) mentioned ligaments in relation to the subluxation of the knee. Galen (130-200 A.D.), the Greek physician and surgeon of the Roman Empire, was the first to describe the ligaments as genu cruciata and state their purpose as preventing abnormal knee motion. The first surgery to repair an ACL was reported in 1900, two years after it was performed.

What are ACL tear symptoms?

Unlike a repetitive motion injury or chronic condition with gradual onset and waxing and waning of symptoms, ACL tear symptoms have immediate onset, as it is an abrupt injury. There is usually a “popping” sound that may be loud enough to be heard by anyone near the injured person, the sensation that something has torn, with swelling soon to follow.

Pain and instability of the knee are a given, although the severity of those may vary depending on whether the tear is partial or complete. The leg may buckle when the injured person tries to stand on it, especially immediately following the injury.

What causes an ACL tear?

As previously stated, there is not much research into ACL tears on the general population, but there has been a lot of research conducted on athletes and some on military populations. Two different mechanisms of injury have been identified: contact tears and non-contact tears, with non-contact tears being more prevalent.

Forty percent of injuries are attributed to non-contact mechanisms involving pivoting, cutting, or jumping. While sports injuries are the most common, they are not the only cause of ACL tears.

Falling off a ladder, missing a stair step, or other type of fall or accident can result in a torn ACL. While the ACL is most often torn by a twisting motion, the PCL is most often torn by an impact, such as a car accident or a tackle on the football field.

Risk factors of an ACL tear

Risk factors of an ACL tear are numerous and complex. Females are three times more likely than males to suffer an ACL injury, and hormones may be a factor. Relaxin, a peptide hormone similar to insulin, has been shown to interfere with the structural integrity of the ACL in women.

An older study on females with ACL tears found that women who had previously had ankle injuries were more predisposed to have injury to the ACL.Youth is a risk factor, peaking at 16 to 18 years. Early and frequent participation in sports is a risk factor; the incidence of ACL tears in children has increased as participation in competitive youth sports has increased.

Another study specific to children and adolescents revealed that risk factors for ACL injury include higher body mass index, subtalar joint overpronation, generalized ligamentous laxity, and decreased neuromuscular control of knee motion.

Genetics may also be a risk factor. A  2016 systematic review of 17 studies concluded that two of the studies observed a familial predisposition to ACL tears, and recommended that more research needed to be done in this area.

A 2009 study concluded the gene encoding for the α1 chain of type I collagen (COL1A1) is associated with cruciate ligament ruptures and shoulder dislocations.

Anatomic differences in bone morphology have also been determined to be a factor; specifically, increased lateral posterior tibial slope (PTS), the posterior inclination of the tibia plateau relative to the longitudinal axis of the tibia, is associated with risk of ACL injury.

Diagnosis of an ACL tear

The gold standard for diagnosing an ACL tear is an MRI, but that is typically done after a focused health history and physical examination raises enough suspicion to warrant the test. Before ordering an MRI, the physical examination would include inspection, palpation, testing of mobility, strength, and stability. The unaffected knee would be examined and tested for a baseline comparison. The MRI will confirm whether the tear is complete or partial. Complete tears are more common than partial tears.

Lachman Test

The Lachman test is considered a reliable test for preliminary diagnosis of an ACL tear, often used on the field by sports medicine doctors when an athlete is hurt, and anytime a patient’s complaint is commensurate with torn ACL symptoms.


The Lachman test is performed with the injured person supine. The knee is passively moved to about 20 to 30 degrees flexion and the leg externally rotated slightly. The examiner places one hand behind the tibia and the other on the patient’s thigh, with the examiner’s thumb on the tibial tuberosity. On pulling the tibia anteriorly, an intact ACL should prevent forward translational movement of the tibia on the femur (“firm end-feel”).

Other tests include the anterior drawer test, the pivot shift test, and numerous lesser known tests. A systematic review concluded that due to decreased sensitivity of Lachman and pivot shift tests for partial rupture cases, and for awake patients, that there are suspicions regarding the accuracy of all tests, and that further research needs to be done. This is probably the reason the MRI is considered the gold standard for confirming the diagnosis.


Torn ACL treatment

One attempt at a critical literature review regarding surgery vs. more conservative treatment for ACL tears states the following:

“Unfortunately, results of most studies cannot be compared because of the following reasons not exhaustively cited: studied populations differed with respect to age, sex, professional and sports activity level, lesions associated with ACL rupture, patient recruitment methods, time from injury to treatment and different therapeutic modalities. Furthermore, various methods were used to evaluate the clinical and radiological results and there was no consensus of their interpretation.

Another systematic review concludes:

“The current literature is insufficient to base clinical decision-making with respect to treatment opinions for people following ACL rupture. Whilst based on a poor evidence, the current evidence would indicate that people following ACL rupture should receive non-operative interventions before surgical intervention is considered.”

ACL repair surgery involves grafts, creating tunnels in the bone to anchor the graft, and hardware. Grafts may come from the injured person’s own patellar tendon, hamstring tendon (autograft), or a cadaver tendon (allograft). There is evidence that an increasing number of patients end up having a second surgery to revise the first.

Surgery for a partial ACL tear sometimes differs from a full tear repair in that the intact bundle of fibers may be used to attach the graft, but in many cases, the surgeon will use the same technique used for a full tear, in order to avoid causing harm to the intact section and because it is a less technically different surgery.

A 2020 study acknowledges that there are controversies when choosing treatment, and states that there are no evidence-based reasons to indicate surgery alone for anyone who tears an ACL. There is also controversy over whether surgery should take place immediately following the injury, or whether there should be physical rehabilitation prior to having surgery.

It is a given that neuromuscular rehabilitation is going to be part of the treatment, whether surgery takes place or not. As is the case mentioned at the beginning of this article, not everyone who tears their ACL is a candidate for reconstruction.

Research shows that among those who do undergo surgery, the function of the knee is unlikely to return to normal pre-surgery function. Not all athletes are able to return to competitive level sports following ACL repair, and are more at risk for subsequent injury.

The appropriateness of surgical intervention may depend on the age of the injured person, other existing health issues, and activity levels prior to the injury. There are also instances where ACL injuries spontaneously heal without intervention.

For athletes in particular, consensus criteria for evaluating successful outcomes following ACL injury include no re-injury or recurrent giving way, no joint effusion, quadriceps strength symmetry, restored activity level and function, and returning to preinjury sports. A systematic review of the literature showed that the average necessary time for physical therapy rehabilitation following ACL surgery is 9 to 12 months.

For those who do not undergo surgery, interventions may include physical therapy, assigned active exercises to be done at home, bracing, and cryotherapy. A Swedish study based on self-reporting from those who had undergone surgery and those who chose non-surgical interventions concluded that patients who chose ACL reconstruction reported superior outcomes for knee symptoms and function, and in knee‐specific and health‐related quality of life, compared to patients who chose non‐surgical treatment.

Please note that the treatments mentioned are not a substitute for professional advice or medical care. You should always consult a physician or other qualified medical professional for both a diagnosis and prescribed treatment.

ACL tear prevention

Without exception, research studies show that people who have already suffered a torn ACL are more likely to have another one than those who have never had one. Those who have had a torn ACL are also more at risk for developing long-term osteoarthritis than those who have not. This applies across all populations, but young athletes have developed osteoarthritis as early as ten years after injury.

Tear prevention is not a guarantee that it will not happen, but it can lower the odds by as much as 50%, according to a study compiling information gathered over two decades.

The study concluded that screening for injury risk for young athletes should be developed, so those at higher risk can be identified, and more appropriate neuromuscular training protocols instituted.

Another review of existing studies concluded that neuromuscular and proprioceptive training appears to decrease the incidence of ACL tears, but stated that there is no evidence for one set of exercises being better than another.

It seems especially important, as children play competitive sports, to implement training exercises that will strengthen the legs and knee on the whole at an early age, which will hopefully be a habit kept throughout their competitive years.

Massage therapy for ACL tears

There is a common denominator among those who have a torn ACL: it’s painful. It is interesting, yet sad, to note that a search for “massage + torn ACL” on PubMed had zero results. A Google search turned up dozens of blog posts, massage technique videos, and advertisements from orthopedic doctors, chiropractors, and massage therapists, but there is no peer-reviewed research.

While the term “orthopedic massage” may be a popular one, it is truly about assessment (again, not diagnosis) more than about any specific massage modality. Assessment, as it applies to massage, is the observation and evaluation of the quality or ability of something, such as whether the client can walk or perform other motions without pain, how the client self-reports their pain level and how pain is interfering in the daily functions, and using active or passive movements to ascertain if the client has full or restricted range of motion.

An assessment can help us to make an informed decision about whether or not to proceed with the massage, and how and what techniques to apply. Diagnosis is the identification of an illness, injury, or condition, and is legally only permitted to licensed physicians and certain other healthcare professionals, such as a nurse practitioner.

Continuing education classes in orthopedic massage usually include examples of orthopedic tests, such as the Lachman test. Performing orthopedic assessments to determine range of motion, for example, are not out of scope of practice, but diagnosing anyone based on any test is out of scope. In the event a client who has not been to the doctor describes their injury, and your assessment causes you to suspect that they have a torn ACL, send them packing to the doctor for a diagnosis.

If you have been practicing massage for any length of time, you have probably experienced someone calling and saying “I just now hurt my so-and-so, can you get me in right now?” Those are usually the people you should decline to schedule until they have seen a physician.

In addition to the intake interview, including a gait analysis can help you see if they are having trouble walking. Palpation will reveal any soreness and particularly tender spots.

Work gently, warming the area before going any deeper. While the work may be focused on the knee, remember that pain in the knee, or a knee that has been unstable (or still is, if no surgery has been performed) may be causing a person to walk differently than normal, limping, favoring the injured side, and could result in pain elsewhere in the body.

At a minimum, most people are stressed out by being injured, and that may be especially true of a college athlete who may be worried about their football scholarship or a competitive athlete who is sidelined. There is nothing wrong with giving a good relaxation massage to go along with the knee work.

Especially for those like my husband, who aren’t candidates for surgery, massage can be a useful addition to treatment. It is best to clear any massage with the patient’s doctor (with their permission), if they are under a physician’s care, and it is vital if their doctor is recommending or has recently performed surgery for the injury.

As with any traumatic injury, you shouldn’t be applying deep tissue massage to a brand-new injury that still exhibits swelling or to someone who has just undergone surgery.

I had the great advantage of being present when my husband was examined by his orthopedic doctor and being able to discuss massage directly with him while the injury was still new. He was in favor of massage to aid in pain relief and didn’t try to give me specific instructions on how to do it.

For those who don’t have that advantage, get as much information as possible during the intake process, such as how recent the injury is, what they were doing when it happened, and what other treatment they are receiving, such as physical therapy, bracing, or self-directed exercises at home.

Remember the obligation to first do no harm.

Feature photo by Patrick Case via Pixabay.

Laura Allen
Laura Allen, LMT
Website | + posts

Laura Allen is President of Sales & Marketing of CryoDerm. A graduate of Shaw University and The Whole You School of Massage Therapy, Allen has been a licensed massage therapist since 1999 and an Approved Provider of Continuing Education under the NCBTMB since 2000. She has taught classes all over the U.S., Canada, and Europe.

She is the author of The Educated Heart, Cultural Crossroads of Healthcare and Healing, and numerous other books. Allen resides in North Carolina with her husband, James Clayton, and their two rescue dogs.