Difficulty with alignment of the knee joints is very common and hopefully a few 'pointers' will help you improve your Taiji practice, and reduce the risk of injuries. Yes ... moving slowly can bring injuries too if you move incorrectly; especially to the knee joints.
caveat: I am not a podiatrist, or any kind of medical professional, so the views and opinions expressed here are personal and do not constitute medical advice. The reader is advised to use their own judgement to take professional medical advice where necessary.
The proper alignment of the knee joint is to be central above the foot, approximately along its centreline, such that the ankle joint is level when viewed from the front or rear.
When standing, as the
knee joint is moved forwards, the ankle joint also flexes. The track of the knee joint, when viewed from above, will be a very slight inward curve, not an absolutely straight line.
You should also observe that the flexion of the ankle joint is actually three dimensional, and accounts for (or is taken account by) the curvature of knee trajectory.
A common problem I see with many people I meet, not only Taiji students, is that the knee joints are slightly collapsed inwards; causing the foot to be unevenly weighted on the floor and the knee joint itself to be slightly twisted during forward movement. The immediate result is reduced biomechanical efficiency, and the longer term impact is likely to be injuries to the knee, ankle and hip joints, as well as knock-on effects in the lower back.
The knee joints are more vulnerable to damage when there is weight in the leg, and doubly so when moving.
Again to emphasise, I am not a medical professional, but there seem to be a few causes and I will attempt to list the ones (I think) I know about:
1. Congenital. We are all probably born with a misalignment to a greater or lesser degree.
2. Excess inward rotation of the femur (thigh bone), often characterised by a muscle imbalance (strength, recruitment or flexibility) around the hip joints.
3. Fallen arches of the feet. This could be congenital, or could be due to muscular atrophy in the ankle caused by too much reliance on shoe insoles. i.e. our feet get lazy and the shoe insoles become a 'crutch'.
Addressing the problem
There is no guaranteed fix, even more so for genuinely congenital issues but, in my own limited experience, many alignment problems can be reduced or alleviated by paying attention in a couple of areas, and of course regular practice.
If you have fallen arches, for whatever reason, you may find that after a period of training your knee may feel 'hot' or the muscles on the outside of your thigh may get tight and tired. Wearing flat soled shoes and custom-made orthotic insoles may help to support your arch, to bring the ankle into a level position. This may help to alleviate the knee pain and muscle soreness, as well as reduce your chances of injury and long term damage (osteo-arthritis?), but it will not undo the underlying cause of the problem, and so if you do nothing else you will be reliant upon the insoles. The intermittent use of insoles during practice, combined with exercises (below) might in some cases lead to a reduced reliance on orthotics over time.
1. Loosen, stretch and strengthen the muscles around the hip joints. The primary aim is to enable the femur (thigh bone) to point in the right direction without straining. Consult your instructor, physiotherapist or other exercise professional for specific advice.
2. Train a "new" knee alignment. Stand in a parallel stance, with the feet shoulder width apart and the outer edges of the soles pointing straight ahead, and then visualise a gentle inward turning intention around the shins and calves, and a gentle outward turning intention around the thigh and knee joint. This will begin to establish a balanced muscular structure that will aid in maintaining proper knee alignment.
3. Strengthen the ankle. Press your big toe gently into the floor to level the ankle joint, while keeping the ball of the foot in full contact. Repeat several times each session and then several times a week to build strength and also new habit.
When training the "new" knee alignment in your Taiji, begin in stationary postures and get "good" at managing your adjustments there first, before progressing to adjustment when shifting weight or stepping. You will need to pay continued attention to your hip alignment, such that the femur is pointing to the right place. The knee joint will be wherever the femur points to. I know that sounds obvious, but it is very important to keep it in mind when correcting the knees. If the hips are not true, the femur points in the wrong direction, so the knees are misplaced, and thus the ankle is supinated/pronated, forcing the weight onto one edge of the foot. The muscles in the calf and thigh will then be tense and any attempt at movement will be painful, trying to move against resisting muscles and not in sympathy with the 'proper' angle of movement for the knee joint.
Correcting the knees when moving requires careful attention. A subtle point that is not commonly noticed, is that when the knee joint moves forward/backward along the line of the foot, the trajectory (when viewed from above) is actually a subtle inward curve, not a straight line. Move and turn slowly so that you have time to continually adjust and correct the hips/feet to keep the knees in proper station.
The body will take time to accept the realignments that you train into it. The nervous system needs to learn a new habit and the tissues will need time to adapt, so you will need to be patient; as if you were filling a bucket with water, one droplet at a time.
When you feel the muscles in your legs getting tight, keep your feet in place but straighten your legs for a few moments to let go of the tension, then return to your posture or movement.
When you get too tired to perform the movements or corrections properly, it is best to stop and allow time for recovery. Your understanding will evolve over time, and you will need to
revisit the above many times and re-evaluate what you can take from it ; and how you apply occupational and biomechanical principles.
I sincerely hope this will inspire you to investigate ways to correct problems you have with your knee alignment, and to seek professional medical advice where necessary.
Comment from some of my Taiji colleagues will be welcome here, and especially those who are qualified to offer medical opinion or guidance?
Paul Fretter, Norwich UK.