Knee Pain in Skiers
Skiing is a sport that is particularly stressful on the knees, and is indeed the region that is responsible for the majority of season ending injuries and up to a third of all injuries in skiers (Owens et al. 2018). If we take a look at the biomechanics of the sport, it is no wonder that we have so many injuries occurring at the knee. The knee itself is a complicated structure that works mostly as a hinge joint, like the one you would have in a door to allow it to open and close. However, the knee is also able to rotate a few degrees when it is totally straight and when it is bent. Our knee is supposed to be able to rely on the relatively mobile ankle and hip joint for motion other than bending forwards and backwards, but in skiing we do two things that force more force to be taken at the knee:
Firstly, we basically immobilize the ankle in a boot, this motion has to be taken up at the knee, hip, and low back. This is also why it is so awkward to walk up and down stairs with your ski boots on.
Second, we increase the lever forces acting on the knee by increasing the length of our feet by 5-6x. Our feet were not really designed to be 6 feet long. Longer levers are more capable of getting caught and generating large amounts of force. Archimedes once said “give me a lever long enough with a fulcrum to place on it and I will move the world.” If Archimedes was a skier, he would probably say something more along the lines of give me a long enough ski with an immovable ankle and I can destroy your knees.
So we have a few biomechanical reasons behind why skiers are more susceptible to knee pain, but there are definitely other factors and injuries that can result in knee pain while skiing. Biomechanics aside, the injuries that we’ll be talking about in this article include: Extremity pain of spinal source, mechanical sources of knee pain from loss of range of motion, muscle imbalance, Ligament injury, meniscus injury, Muscle injuries, Bone stress injuries, and failed rehab after surgery.
Extremity Pain of Spinal Source:
This is simply a fancy way of saying knee pain that originates from your back. There are multiple conditions in which we can have leg pain that comes from the low back such as a disc herniation and radiculopathy, the so called “sciatica” (which is a weak diagnosis at best, read this article for more info as to why sciatica is a poorly used term and not very helpful), and others. What research is now finding out is that we can have pain in our extremities such as our knees, shoulders, ankles, and even wrists and fingers without having the neck or back pain to go with it. In a fairly landmark paper, Rosedale and colleagues found that spinal sources of extremity pain were as high as 43% in total and 25% of knee pain patients. To be clear, just because you have knee pain this DOES NOT mean that it is always coming from your back. In order to actually tell if your knee pain is coming from your back an evaluation has to be performed. In this evaluation, we see if moving your back in certain directions affects the pain and function in your knee. If a chiropractor, physical therapist, Medical doctor, trainer, Swamy, fortune teller etc.. Tell you your knee pain is coming from your back without doing an evaluation, they are guessing. Which is fun in go fish, but not in management of knee pain.
Mechanical Issue from lack of motion
Mechanical issues in the knee can be quite prevalent and when found, can be treated quickly and effectively with specific exercises (i.e. not the random stuff you find on YouTube or instagram, but speaking of shameless instagram plugs please go and follow us @summitchiroandrehab on both instagram and YouTube). In order to perform a proper assessment of the knee, we have to look at your personal range of motion, and how it compares to what it should be for an individual with your personal history; taking into account prior injury, surgery, connective tissue laxity etc… Then we can perform a movement assessment to see if specific movements have an effect on your pain and the function of your knee. If we can establish a specific motion or movements that decreases your pain and also improves your function in tests that were previously painful ( a deep squat or lunge for example) then we know what specific things we need to do to treat you as effectively and efficiently as possible.
Muscle imbalance?
What a tricky term that is CONSTANTLY being thrown around in the rehabilitation setting. I personally do not like the term, and do not like using the idea of muscle imbalance in the office because I do not personally have the option of recording muscle activity on each patient that I see. I do really like increasing patients movement options, as well as adding strength in areas like the hip that have been shown to increase stability and capacity in the knee itself (Mucha et al. 2017; Fredericson et al. 2000; Willy et al. 2019).
Ligament injuries:
A tough topic here because some ligament injuries can (and should) be treated conservatively and without surgery, while some will likely need surgery to repair important structures that provide the knee with some crucial aspects of stability. The four major ligaments of the knee that provide really important stability for skiers are the Anterior cruciate ligament (ACL), Posterior Cruciate ligament (PCL), Medial collateral ligament (MCL) and the Lateral Collateral ligament (LCL). One of the most important things that we do in our office regarding knee pain is a thorough assessment and evaluation if you are a good candidate for our care. Complete tears of one of these ligaments compromises the structural integrity of the knee and leads to significant laxity, which can then lead to damage in other areas and tissues of the knee, which can predispose you to arthritis and joint damage. Luckily, orthopedic tests as well as thorough history taking (both of which can be performed by trained sports chiropractors) can be effective in figuring out if a referral to a surgeon or for imaging is necessary. Complete tears of the ACL and other ligaments are the best candidates for surgery, but minor tears and sprains of ligaments like the MCL and LCL are very effectively managed with non surgical means. The best way to manage these is through a combination of manual techniques and guided rehabilitation which can be performed by sports chiropractors and physical therapists.
Meniscus injury:
This one can be tricky and there have been a lot of recent developments in the literature regarding how meniscus tears are managed. There have been really interesting trials that compare the effectiveness of surgery with placebo surgery. To do this they literally put people under anesthesia and then perform incisions, but do not actually take out the damaged piece of meniscus. They they compared the effectiveness of the surgery after both of the groups completed physical therapy, and found them to be EQUALLY EFFECTIVE (van de Graaf et al. 2018). Obviously there are specific types of tears (bucket handle tears) that do need to be surgically corrected, and some people’s knees just don’t respond to conservative treatment. Unfortunately, even the most experienced practitioners cannot predict who is going to benefit from surgery, and who is going to benefit from rehab and time (Bloembergen et al. 2020). The best and most cost effective way for people to manage their meniscus injury is to start with 3-6 weeks of conservative therapy, and then if that doesn’t work move on to getting the opinion of an ortho.
Here is a testimonial from a patient one year after treatment at our clinic for knee pain while skiing that likely had meniscus involvement
Muscle Injury:
There are many muscles that come down and connect to the knee joint including but not limited to the quadriceps, hamstrings, popliteus, and the gastrocnemius. Muscles have the potential to be strained and partially torn. In these events people usually feel a pop or a ripping sensation in the belly or bulky part of the muscle, followed by bruising and then pain with activating the muscle.
If the muscle is not completely torn, then it can be managed conservatively. (If completely torn the muscle rolls up into one side of the extremity like a window shade).
Rehabbing these injuries properly is important, and it can also be sped up with various manual therapies like acupuncture, massage, and cold laser. Rehab itself consists of gradually loading the muscle that was damaged.
Patellofemoral pain syndrome:
This is an interesting pain manifestation behind the kneecap which causes pain while squatting, going up stairs, and can even present after sitting for long periods of time. We used to think that the patella was tracking incorrectly along the condyles of the knee and that these “tracking issues” led to abnormal wear and tear and then pain the back of the kneecap. Unfortunately, tracking the patella is easier said than done, and when we do track it, it seems as though all tracking manners are present even in people without pain in their patella. A few things that were found to be very helpful include some manual therapies along with active exercises. These HAVE to be done together because performing one of these alone is not superior to doing both. The manual therapies that can be helpful to the recovering knee include soft tissue therapies like pin and stretch of the muscles surrounding the knee, as well as acupuncture. The rehabilitation of this injury has also changed significantly in the past 5 years. We once thought that we needed to target the tracking issue of the knee and support it with tape in controlled ranges of motion. However, this has been found to be less effective than a graded loading program to the extensors and stabilizers of the knee. Ironically many of the major stabilizers of the knee are located up in the hip. The muscles in the outside and back of the hips are major players of knee stability, and can be easily strengthened with specific exercises that do not even require a resistance band or tape ((Willy et al. 2019; Winters et al. 2020)
Knee Arthritis:
Previously thought of as a solely structural and “wear and tear” type issue, we now know that many factors go into making an arthritic knee painful (also here we are going to be talking about osteoarthritis, and not the various other forms of arthritides that can affect the knee joint). These factors range from overall inflammation, to simple muscle weakness. A large study of over 46,000 people found that weakness in the knee extensors (quads) was a risk factor for the development of knee osteoarthritis (Øiestad et al. 2021). This is definitely one of the cases in which preventative measures for knee arthritis really include resistance training of the knee. In the treatment of knee arthritis itself, contrary to what some may believe, movement can be exceedingly beneficial whether that be walking, squatting, lunging, or running. Long term management with over the counter anti inflammatories and injections are potentially dangerous in that they may decrease what cartilage is left in an unhappy knee (Perry et al. 2021; Singh et al. 2021; Orchard 2020). Some things that may be beneficial include supplementation with collagen peptides and also movement assessments to look for a direction of preference (Zdzieblik et al. 2017; Rosedale et al. 2014).
Bone stress injury:
This is one of the sneaky underlying conditions that can contribute to knee pain for a long period of time. Bone stress injury is not something that is caused by a trauma, but builds over time, kind of like a stress fracture. The best way to treat these injuries is to rest and allow the bone building cells (osteoblasts for you physiology nerds out there) to build up and strengthen the area that is injured. If loading and activities outpace the bone building cells activity, then you will experience prolonged and worsening of symptoms. It is important to stress nutrition and energy availability (eating amounts that are appropriate for your activity levels) in order to create the best environment possible for the bone building cells to repair the damaged area of bone as quickly as possible.
Failed Rehab:
There are a lot of factors that go into post surgical rehabilitation of the knee. Many of these factors can complicate rehabilitation, delaying recovery, or leading to an outcome that does not match with your goals. Sometimes there are also other overarching issues that can contribute to poor outcomes (some of which were discussed earlier in this article). So having someone that can take all of these variables into account can be very helpful in improving an unfavorable outcome. Some of the biggest issues that I see are loading and capacity issues. For instance it is one thing to rehabilitate someone back to “normal,” which in the United States is a largely sedentary lifestyle, but another thing entirely to get ready again for an activity like skiing. For the most part. In order to have the connective tissues ready for skiing, we have to really be sure that they can take the loads associated with skiing, while not exacerbating pain or injury.
Another circumstance that can exacerbate knee pain is if you stop rehabilitating and strengthening the knee after surgery. We have to remember that once we put in the work to get the knee back to feeling strong and healthy after surgery, the work is not done. Strengthening exercise for the knee is like watering a plant, if you do not continually water a beautiful plant, then that beautiful plant will shrivel and die. Our muscles work in a similar way, except resistance training and exercise are the water… (ok our muscles need real water too but that’s not the point here). If you are struggling with a post op knee issue, then a second opinion can be helpful and useful.
This patient of ours had a history of multiple necessary orthopedic surgeries after a ski racing crash. She then had a setback which exacerbated her symptoms in her hip. After following her treatment plan and doing her at home exercises she is back to doing the things that she loves in the outdoors.
References:
Øiestad, Britt Elin, Carsten B. Juhl, Adam G. Culvenor, Bjørnar Berg, and Jonas Bloch Thorlund. 2021. “Knee Extensor Muscle Weakness Is a Risk Factor for the Development of Knee Osteoarthritis: An Updated Systematic Review and Meta-Analysis Including 46 819 Men and Women.” British Journal of Sports Medicine, December. https://doi.org/10.1136/bjsports-2021-104861.