Quads And Squats

We saw a few patients who tore their Anterior Cruciate ligament (ACL) in our clinic this past week. I have written many articles on the ACL before. Once you've torn your ACL, it usually takes 9 to 12 months before you can return to your sport, not to mention the financial cost. 

I came across an interesting article summarizing the evidence of the relationship between muscle forces acting on the ACL. This is important since muscles around the knee can increase and decrease the strain and mechanical loads on the ACL. This presents opportunities for preventive intenventions. 

Subsequently, our staff had interesting discussions regarding that article (referenced at the end of this post). The article demonstrated the forces acting on the knee joint and what can cause injuries there, specifically, what can hurt the ACL. 

The article reviewed muscle and and ACL loads during knee bending as well as weight bearing tasks like walking, lunging, landing, jumping and sidestep cutting.

Ready for the results? The quadriceps (thigh muscles) and gastrocnemius (calf muscles) increases load on the ACL due to anterior shearing forces at the tibial (shin bone). This is especially so when the knee is straightened.

The hamstrings and soleus (deeper calf muscles) helps to unload the ACL by generating posterior tibial shearing forces. For the hamstrings to 'protect' your ACL, your knee has to be bent at least 20 to 30 degrees.

R gluteus medius

The gluteus medius muscle was demonstated to consistently prevent the knee from collapsing inwards (knee valgus movement) and thus unloading the ACL, better than any other muscle.

Surprised? 

Patients who have been been told to strengthen their quadriceps (especially after ACL reconstruction) were really surprised when we told them. Make sure you focus on your hamstrings and soleus muscles instead.

The muscle to rule them all is of course the gluteus medius. Our patients will now understand why we always ensure their gluteus medius muscle is strong to prevent knee pain, Achilles tendon and of course ACL injuries.

Now you know.

Reference

Maniar N, Cole MH, Bryant AL et al (2022). Muscle Force Contributions To Anterior Cruciate Ligament Loading Sports Med. DOI: 10.1007/s40279-022-016743

My Patient Was Told He "Just" Tore His Lateral Meniscus

Maybe it's not so obvious from just the picture above. But when I looked at my patient's legs, they were the first clue I received that perhaps there was something more than meets the eye.

He had gone on a skiing holiday in Whistler in March earlier this year and suffered a fall. After being brought to the physiotherapy clinic on site, they just gave him a knee brace and told him that he tore his lateral meniscus and that it will recover in a month or two. He actually felt fine after a few days of resting and thought he recovered fully after returning to New York where he's studying.

Two months later, when he tried to play tennis once, his right knee "gave way" and he had a very sharp pain for a few seconds. That actually subsided quite quickly too. Similarly on another occasion when he had a kick around game of football with his friends, his knee collapsed again.

He then mentioned that he wasn't confident about running, playing sport with his knee since even it seems to him that he'd recovered.

From what he told me, I immediately suspected he'd tore his Anterior Cruciate Ligament (ACL). Not wanting to "scare" him at first, I didn't say anything to my patient I went through all the ligament and joint testing thoroughly.

After checking his patellofemoral and tibia femoral joints, I did the Lachman's test, Reverse Pivot Shift test and the Anterior Drawer Test for the knee and they were all positive. (I seldom get a positive result for the Anterior Drawer Test but for him there was pain and a big difference in laxity compared to his other leg).

My patient was very shocked when I told him that he'd torn his ACL based on my assessment findings. He wasn't very convinced at first until I explained to him what I found based on his history, the positive orthopedic tests (and the fact that the physiotherapist in Whistler didn't actually examine him). Later he added that no wonder his knee never felt quite right after the skiing trip and now he knew the reason for it.

From my patient

He later went to see his general practitioner doctor and got a referral for a MRI scan and he later messaged me the result as you can see in the picture above.

After some consideration, he decided to do his ACL reconstruction yesterday in Singapore instead doing it elsewhere. Here's the picture he sent me upon discharge from hospital today.

Picture from my patient

It's not the the first time I have a patient who tore his ACL but the previous doctor/ medical practitioner/ physiotherapist they went to first missed it.

Please make sure whoever you see for your knee pain assesses your knee thoroughly.

Popliteus Is The Problem, Not Baker's Cyst

Back of L leg

I had a patient who came to our clinic this past week complaining of pain in the back of her knee. She looked at her symptoms online and thought she had a Baker's cyst. One look at it and I told her not a chance of it being a Baker's cyst.

After examining her knee carefully, I told her it was her popliteus muscle bothering her.

Here's some background information about my patient. She was about 13 months post ACL (anterior cruciate ligament) surgery, back to weight training, running and training two to three times a week for netball.

Now, as far as I remember, every single patient who've undergone an ACL reconstruction I've treated have had a problem with their popliteus muscle at some point or other.

The popliteus muscle is triangular in shape sitting at the back of the knee. It starts on the lateral femoral condyle (posterior, outer part) of the femur (thigh bone) and the lateral meniscus. It then runs down and across the back of the knee joint to finish on the posteromedial (inner) part of the tibial (shin bone).

R popliteus

The muscle limits excessive internal and external tibial rotation. It helps straighten your knee from full extension by rotating the tibial internally. It also "pulls" the lateral meniscus out of the way during knee bending to prevent too much compressive forces from the femur of the tibial so you don't tear your lateral meniscus.

The poplitues muscle is very seldom the main cause of the problem. There is usually a problem with other stabilizing strutcures in that posterior lateral corner of the knee. It is often hurt because of compensating mechanisms related to that. Such has hip rotator weakness that transmits excessive forces towards the knee. Also, hamstring weakness with hip, knee pivoting movements, which are extremely common in netball.

Consider that most ACL reconstructions for patients now are done usually using the hamstring grafts so the hamstring is consistently weaker thus causing the injury/ strain to the popilteus muscle.

Treating the poplitues muscle for my patient was the easy part. I got her pain free at the end of the session. Ensuring the pain does not come back is trickier.

She needed to address the weakness in her hip stabilizers and hamstrings to prevent the problem from coming back. And that will take some effort on her part.

How Effective Is Your Knee Brace?

Assortment of soft knee braces from the Holland Village Guardian

How many of you have seen runners run past with a knee sleeve/ brace on? That's what I always look out for! But that's me and that's what I always do, watching people move and see if there's anything wrong or different.

I've also seen so many of my patients walk in to our clinic with a self prescribed over the counter soft neoprene knee sleeve/ brace. Often, they are asked by the doctors they see to wear a brace.

Often prescribed by doctors

I always ask the patients why they have the sleeve/ brace on. Some will say the brace helps with their pain or it makes their knee feel less wobbly. They usually reply that they feel a little more secure with the sleeve / brace. Most, however are not sure if the sleeve/ brace works.

Let me explain what the differences are. Braces that are stiff and rigid are usually made from plastic, aluminium or carbon fibre. They usually restrict joint movement by physically pressing against the bones of the knee to provide firm external support.

My patient in his rigid knee brace 

While the rigid knee brace can help restrict or limit movement, there is a definite downside  to using them. Have a look at my patient who had a tibial plateau fracture and a partially torn anterior cruciate ligament (ACL).

Check out the rigid brace

See the difference in thigh girth?

Since knee movement is often limited and restricted, the load is often transmitted to the ankle, hip and lower back. Often I end up treating them for the back pain too.

The softer neoprene type sleeves usually will not be able to provide the same mechanical support as they are much softer and do not have any rigid structural support. Neoprene sleeves generally help the wearer by increasing proprioception (or joint position sense) much like the high cut shoes basketball players wear to give themselves more awareness of their ankles to prevent ankle sprains. It is believed that improved proprioception around a knee joint can help stability by improving balance.

However, a 2012 published study of people with knee arthritis found no significant improvements in balance with the use of a neoprene knee sleeve.

There is also very little evidence that knee supports worn prophylactically on healthy knees protect active people against knee injuries.

Granted, knee supports/ braces are usually less expensive or as invasive against knee operations to treat injuries or even arthritis so so people will try them before resorting to surgery.

Some specialized knee supports may help to take pressure off the knee joint while walking and especially during exercise. My patient (in the picture below) intends to use her brace when she goes back to wake boarding and skiing after her injury. Of course I added that proper rehabilitation is important too. Such braces may also be able to help patients with knee arthritis remain active and put off surgery at least for a while.

All ready for action

As explained above, rigid knee braces (but not sleeves) may help after some knee injuries. They are often prescribed by doctors after a patient suffers a torn medial or lateral collateral ligament (LCL). MCL's and LCL's tends to heal fairly well without surgery provided there is no further strain/ injury to the knee for the first 6-8 weeks after the initial injury.

Bracing can be effective when you know what injury you have and the structures involved as a brace can be matched effectively to your needs.

My MCL taping- "Much better than any brace" says my patient

I always prefer to tape compared to using a brace though. As I always say to my patients, I can customize the taping according to their needs and it always fits better than any brace they buy.

So don't just go and buy a sleeve/ brace.


Reference

Collins AT, Blackburn JT et al (2012). The Assessment Of Postural Control With Stochastic Resonance Electrical Stimulation And A Neoprene Knee Sleeve In The Osteoarthritic Knee. Arch Phys Med Rehab. 93(7): 1123.1128. DOI: 10.1016/j.apmr.2011.12.006.

*Big thank you's to all my patients who allowed me to take pictures or sent me pictures.

Running Injuries? Blame Your Genes?

Chromosome by Hey Paul Studios from Flickr

All right, it's finally been proven, some people are more prone to injury than others. So says a newly published article from the British Journal of Sports Medicine.

The researchers found evidence from family and genetic studies that DNA sequence variants (together with non-genetic factors) can increase your risk for tendon and ligament injuries. This is for both exercise-associated and occupational-associated acute and chronic injuries to tendons and ligaments.

Although research at this stage is still preliminary, there have been specific gene variants found (COL5A1 gene) that are less likely (58 percent less) to cause Achilles tendinopathy (degenerative change in the tendon).

A different gene (COL1A1) is associated with ACL (anterior cruciate ligament) and Achilles tendon ruptures (September et al, 2009).

In fact, several other genes have been associated with injuries ranging from carpal tunnel to tennis elbow.

The common link among these genes is that they affect collagen fibrils structure. Collagen fibrils are the basic structural building block for tendons, ligaments and other connective tissue including fascia. In simple terms, some Achilles tendons are built better than others.

So what do you do with this information then? Athletes and coaches beware, especially when there are now many genetic tests marketed for self testing promising to reveal potential injury susceptibilities.

The researchers reported that such tests should be requested by an appropriately qualified healthcare professional since results need to be interpreted together with certain clinical indicators and other lifestyle factors.

Personally I'm fairly sceptical about such over the counter/ online genetic tests that you can purchase to do a self test on whether you're more prone to injury.

Will knowing that really change your training habits? As a previously compulsive competitive athlete, I trained as hard as I could handle and more without getting injured. Knowing I'm say, 10-20 percent more likely to get a tendon injury will not alter my day to day training. On the contrary, because I've been training hard for so long (previously), I know what injuries I'm prone to because I've already had them previously.

Hmmm, maybe from now I'll ask my patients whether they have a family history of tendon or ligament injuries instead. (Standard practice for Physiotherapists is asking patients if they have any family history of hypertension, heart diseases and cancer etc).


Reference

Collins M, September AV and Posthumus M (2015). Biological Variation In Musculoskeletal Injuries: Current Knowledge, Future Research And Practical Limitations. BJSM. DOI: 10.1136/bjsports-2015-095180.

September AV, Cook J et al (2009). Variants Within The COL5A1 Gene Are Associated With Achilles Tendinopathy In Two Populations. BJSM. 43: 357-365. DOI: 10.1136/bjsm.2008.048793.