Knee pain - compensatory mechanism

Patients suffering from knee pain (secondary to osteoarthritis or any other pathologies) have difficulty in getting up from lower surfaces like a sofa or the floor. Some of the patients present to the clinics with knee pain and usually also present to the clinics with pain from multiple joints, that can be attributed to the knee. How? Will try to explain my reasoning for the same. 

Those presenting with symptoms of knee pain vary from pain only on provocation  (sitting cross-legged, squatting or negotiating stairs), to severe pain with difficulty in walking or standing. All of these patients require to sit and here is the root of the problem for involvement of other joints and for the knee to remain painful. These patients, commonly females, would indulge in floor sitting irrespective of the fact whether they are able to undertake them or not or they will sit on elevated surfaces which are of inappropriate height and firmness.

The elevated surfaces for sitting (usually sofas), by design, are generally low in height and the softness of the material makes it more lower once a heavy patient sits on it (heavy patients face a greater difficulty). If the sitting surface is broad the patient has difficulty in sitting properly in an upright posture and slouches. This is primary the case for the housewives or the retired population or those leading a sedentary lifestyle. 

When such a patient wants to rise after sitting, he or she usually would do so from the depth of the sitting surface which requires to exert pressure on the upper limbs, buttocks, spine and the feet to raise himself or herself. This mechanism is adopted so as to safeguard the painful knee. This reduces the load on the painful knee and exerts extra load on the other joints. More heavy the patient , more the load on the knee and the other joints. While rising from floor sitting, patients suffering from symptomatic knee will try to exert their full body weight on the upper limbs, smaller joints of the feet and back, assuming a four pedal stance, putting the joints of the two upper limbs under tremendous stress and potential injury.

This repetitive stress on all the joints produces damage to the already ageing tissues of this joints. These joints have already had their share of wear and tear secondary to their primary role in the routine life. The additional insult to protect the knee joint makes them prone to more wear and thus the pathologies in them. The joints which take the brunt of this repetitive stress are usually the shoulder, elbow, fingers, wrist, low back and small joints of the feet. Such patients, with long standing symptomatic or subtle osteoarthritis of the knee, develop polyarthralgia which can become the presenting complaint. These conditions develop due to the fact that multiple lower limb and upper limb joints are being used while rising from sitting and also while undertaking other knee provocative activities (stair climbing, kneeling, squatting, sitting cross-legged). The joints are called for action to compensate for the lack of action at the painful knee.

The common presentations for which knee can be seen as a culprit are

• progressive pain and stiffness at the shoulder with restricted activity or an acute attack with loss of movement
• pain at the elbow, non dominant extremity in particular
• pain and swelling at the wrists, small joints of hand. The thumb gets primarily involved with pain along its entire course or locking.
• tingling numbness both hands
• chronic and acute on chronic episodes of low back pain 
• pain in the buttocks, anterior thighs, heel, back of the heel, forefoot
• pain and swelling at the ankle, more on the medial aspect
• any other pain in the lower limb which is more while getting up after sitting and which reduces once the patient starts to walk.

Sitting cross-legged:
The compensation is also done to complete a seemingly innocent activity like sitting cross-legged. Due to the painful knee, the user will not be able to completely flex the knee and thus exert extra external rotation and abduction pressure at the hip (to complete the posture), making them vulnerable to pain. The patient with a painful knee evolves a compensatory gait at the hip such that the thighs are feeling nearer to the center of the body, which weakens the hip abductors and external rotators (muscles responsible for moving the hip out) and tightens the internal rotators and adductors at the hip (muscles responsible for moving the hip inwards). This leads to reduced freedom of movement at the hip required to sit cross-legged which puts extra pressure on the painful knee and thus it becomes a vicious cycle. 

Thus knee should always be examined for signs of involvement (more patello-femoral) in patients who usually present with complaints suggestive of repetitive stress in the upper limb joints or lower limb joints, 

Knee pain - difficulties faced by patient

These difficulties (symptoms) of knee in the initial stages are due to the involvement of the knee cap (patellofemoral) joint. The knee cap joint is where the knee related problem begins (3rd-4th decade of life) which then extends to the tibio-femoral joint (classical knee joint) in due course (2-4 decades). All patients with tibio-femoral joint will have symptoms of the patello-femoral joint and in addition will have varying degree of difficulty in walking.

What are the difficulties experienced by the patient that are typically attributed to the knee cap joint?
  

• Need to straighten (extend) of the knee: this is one of the earliest symptoms for the patient to experience. This happens when the patient is sitting cross-legged and after some time he or she feels the need to straighten the same to feel better. The patient may experience discomfort, pain, stiffness or sometimes numbness while sitting with leg crossed and will find relief on straightening the same. With this symptom once the patient tries to rise after prolonged sitting he or she may experience an initial hesitancy to walk which would completely disappear after some steps and once he or she starts walking they will have no pain or discomfort. This symptom is so subtle that they usually attribute to increasing age or weight. In the younger population if it is a regular feature then it can be a presenting complaint.
• Pain while sitting: This is an unnerving symptom classically attributed to knee. This usually happens when the person encounters situation where he or she are sitting for prolonged duration which may be the case while sitting at work, driving (especially when there is too much traffic and if the clutch needs to be repeatedly used), watching movies, or sitting in yoga asanas (sukhasan, vrajrasan). They will be having varying degree of pain ranging from dull ache to throbbing type which will make them limp for a few steps and once walking the symptom will subside completely.
• Pain/Discomfort while rising after prolonged sitting (chair, travel, movie, floor): This is a very characteristic feature of pain originating from knee. The patient can complain of knee as a source of pain and it can be a compensatory overload of any other body part (commonly heel and buttock) who have similar history. Knee is the only joint, rather the knee cap (patellofemoral joint), which characteristically will have maximum symptoms following rest and once the person is active, the symptoms will reduce and sometimes the patient will even forget about the same. For pain originating from any other joint in the lower limb (tibio-femoral, hip, ankle, feet), the pain has to increase on walking due to the mechanical overload happening. Only pain originating from the patello-femoral joint will reduce or be absent once the person is walking briskly or running. This pain becomes so discomforting that patients overload the other body parts (wrists, shoulders, feet, heel, buttock) and make them vulnerable to injury and pain.
• Pain while negotiating stairs/slopes: This is also one of the earliest features evident especially in young. They usually go for a picnic where they need to indulge in a trek or slopes and the problem becomes evident. Otherwise it remains subtle as stair negotiation has reduced drastically in the affluent class. It is still prevalent in homes of super affluent (duplex flats) and those homes where there is a need to negotiate stairs more frequently. The stairs in question are influenced by the height of the patient and height of the stair. The higher the mismatch between the user and the step height more the difficulty. On the other hand, even a simple step can be difficult to negotiate in a person with advanced problem in the knee. Such patients have difficulty in climbing in a bus, train, crossing the dividers on the road, climbing the footpath and require to take some support and they always prefer to load the less painful knee.

Any one suffering from any one of the above mentioned difficulties must accept that they are having an issue with their knee. They cannot attribute it to age, weight, menopause, deficiencies, rheumatism. The patient with the classical rheumatoid arthritis will have more severe form of the problem, will always have associated swelling and the handicap will be more pronounced. If identified early, treated appropriately with the taping treatment (along with soft tissue stretching) and the weight kept under control, then there are fair chances of keeping the problem under reasonable control.

Knee pain - Types of Presentation

There are a host of complaints that patients come which can be directly or indirectly related to the knee. They are so diverse that it becomes difficult for the patient to get convinced that their knee is the offending organ. Some of them have never experienced any pain in the knee and have modified their lifestyle in such a way that the knee never gives them the trouble. But on deep probing they will all have symptoms which are characteristic of knee involvement. In modifying their lifestyle they will knowingly or unknowingly overload various other body segments and injure them. The lifestyle gets modified by slowing down in their activities, avoiding activities which they know are discomforting, learn from their pains and do the right things based on their experience.

A case history:

55 year old female comes with history of pain in the inner aspect of her both thighs since a month. She has no history of trauma, injury or slip. She has history of sitting cross-legged on the bed and working on the laptop. Another significant history was that she had changed her car and moved to a lower height car and it turned out that her pains started immediately after the change in car. Her past history revealed that she is having difficulty in sitting for prolonged duration and hence have stopped going for a movie. She has a very tough time while travelling by air on long journeys. Her walk has slowed down dramatically but she is managing her life as her executive job provides her with all the luxuries. On examination she had definite findings suggestive of knee involvement with pain on touch in her inner thighs. Her muscles around the buttock, thigh and leg were all tight. An innocuous stretching of all the muscles and offloading of her patella made her feel light and relatively pain free. She was advised to go back to the tall car, stop sitting cross-legged, take frequent breaks while sitting and encouraged to walk. On the next visit she was completely relieved of her inner thigh pain, she was convinced that knee is the reason and her knee was addressed with soft tissue stretches, patella mobilization and patella taping.

The point is that the patient managed her lifestyle with all the handicaps for 8-10 years and the day her compensation failed or got overloaded she sought opinion. It were her symptoms that led to the thought process of knee being the culprit.

Some people will come when their knee related compensation mechanism fails. This means that they are aware about their knee giving them trouble but they are somehow managing by under using that knee and overusing other body part (s), either of the same leg or of the opposite leg. These body part (s) being virgin on their own have a good tolerance capacity to bear the over load. Until and unless that compensatory body part is functioning within their functional zone the person is managing his or her daily life, albeit in a compromised manner. The day the compensating body parts start failing the patient visits the doctor in a distress situation. The compensating body part needs to be addressed as need be but if the eyes are kept open and a proper analysis (history and examination) undertaken then the culprit will be identified and that would be the knee. The compensatory part (s) can be the heel, calf, buttock, thigh, other knee, shoulders, or elbow & wrists.

There is a big group of patients who will approach the doctor for the specific knee related symptoms. Most patients will present only when their knee becomes non-functional in some form of the other (difficulty in walking, limp, inability to sit for long). They would be suffering from the symptoms since few months to years but as they are managing with them and it is not interfering with their mobility and independence they are not alarmed.

We will see the specific symptoms in detail in next post.

Knee pain - Introduction

Knee pain!!! One of the commonest and under-treated symptom amongst the Indians which has long term ramifications (we will explore them in subsequent posts). It is found more prevalent in women especially after the age of 30 years. The knee pain in young and the middle aged are seen to be two different entities based on the the primary joint involved, viz; the knee cap joint (patellofemoral : knee cap in front & the thigh bone below) is seen as the culprit for pain in young and the main joint (tibio-femoral) between the thigh & leg bones in the middle-aged and above.

They are seen to be exclusively independent which I feel is not the case. I am convinced that the patellofemoral pain is the beginning of the entire journey of knee related problems culminating in the potential progressive deterioration and producing corresponding handicap and disability. Thus, the knee pain in young gradually extends to the knee pain in middle-aged & elderly and it can take anywhere between 10-30 years for it to reach a stage necessitating surgery, depending on the weight, age, and if it is due to diagnosed Rheumatoid Arthritis (RA), a little earlier as well.

The incidence and prevalence is increasing by the day and even younger people (male and female alike) are experiencing this problem. There are various theories subscribed to this increased frequency which in my opinion are at best associated factors and not causative. Why associated?

• Weight: All patients with knee pain are not necessarily over-weight and all obese/overweight patients don't experience knee related symptoms of the same severity. 
• Vitamin D3 : It is seen that patients with knee pain may have Vit. D3 deficiency but all people with Vitamin D3 deficiency don't have knee pain.
• Aging: Very subjective as all people of the same age, sex, weight, height don't experience the same type of problems
• Rheumatism: It is usually inferred that if more than one joint is paining and if the ESR (blood test to identify chronic problem) is high beyond its range, then the patient is labelled to be suffering from rheumatism (sero-negative RA), even in the scenario where the rheumatoid specific tests are negative.
• Weakening of bones: just because the patient is a women, attributing all unexplained pains to weak bones is an unacceptable excuse.

Are the above mentioned factors irrelevant? NO. I am not sure about the others but weight and age have an influence on the progress of the problem. The more the weight and the age at onset of the problem, more the chances of progression. 

So, what is the cause for knee pain? How does it progress? Is it only about the  Most importantly how to we treat? Role of taping? We will dwell into the various aspects in the forthcoming posts.