The vast majority of us take walking for granted. Walking is actually a complex task that involves a large amount of synergy within the human body. For all of our stroke clients, the intricacy of walking becomes more difficult, and requires a much more conscious effort. For some, it is a minor limp, for others it is the inability to take a step without a frame or assistance from another person. Whatever your walking level is post stroke, here are some ways we can help you get back to a more normal gait pattern.
This article helps you understand walking in 3 ways:
1. The essential components of walking
- Heel Strike – the heel lands to start the loading response
- Foot Flat – the foot accepts the body weight and the knee and hip bend slightly
- Mid-Stance – the full body weight is taken up and the body rises up while the other leg swings
- Heel-Off – other leg lands while the weight transitions off
- Toe-Off – push off the ankle and foot happens and stance finishes
- Mid-Swing – the limbs swings in the air, preparing itself for the next heel strike
Each of these components require a certain amount of range at the ankle, knee and hip joints, which are specific to each phase of the walking cycle.
2. What changes after an acquired brain injury
- Stroke and brain injured survivors have decreased joint ranges at the ankle, knee and hip. The decreased amplitude is associated with decreased velocity.
- There is abnormal coactivation of leg muscles, which limits synergy as well as the limb’s capacity to absorb and store energy.
- Stroke patients also have a low level of power generated by the ankle (which would affect push-off). They have increased tension in the Achilles tendon due to mechanical changes in the muscle fibres themselves.
- This results in:
- decreased walking speed
- short and/or uneven step and stride lengths
- increased stride width
- dependence on support through the hands.
3. How do we treat these changes
The exercises we prescribe are trying to replicate the specific actions of each muscle, as this ensures a carryover effect that will begin to normalise walking.
In my experience, the most effective way to generate muscle force and learn how to synergise movement is to load the affected leg (i.e. stand on it). Loading the affected leg emphasises the extensor muscles of hip, knee, and ankle, since these muscles provide basic support, balance and propulsive functions.
- This begins with symmetrical weight bearing.
- Then we would progress to taking steps with the unaffected foot, maintaining the load on the affected leg. Stepping can be done sideways, forwards, backwards, as well as up and down.
- If the client is unable to support their own knee or ankle (due to poor muscle activity), devices such as calico splints, taping, and ankle-foot orthoses will help to stabilise knee and ankle joints respectively.
- Sometimes it is ideal to use a treadmill belt, particularly in clients who have difficulty un-learning their concentration used to step, which results in very short, awkward stepping. The treadmill also allows us to facilitate the stepping pattern through manual guidance, and alter the speed appropriately to achieve the best coordinated pattern. It also allows us to grade the slope, which challenges different muscles selectively, over many hundreds of repetitions in one treatment session.
- While repetition important, the key is variety
However, the capacity to walk in a community setting requires the ability to walk at speeds that enable an individual to cross the street in the time allotted by pedestrian lights, to step on and off a moving walkway, in and out of automatic doors, walk around furniture, under and over objects and negotiate kerbs.
It requires that we change the way we stride, at any moments’ notice, in both space and time. This is called motor redundancy and our nervous system selects the most appropriate output, in response to oncoming change. We then use a combination of predictive and reactive strategies to then allow us to move through the street successfully. And because they happen so quickly, we can easily take walking for granted.
Resources: Carr, J., Shepherd, R. (2003). Stroke Rehabilitation: Guidelines for Exercise and Training to Optimize Motor Skill, First edition. Forssberg, H. (1982). Spinal locomotion functions and descending control. In Brain Stem Control of Spinal Mechanisms. Elsevier Biomedical Press, New York. Hill, K., Ellis, P., Bernhardt, J., et al. (1997). Balance and mobility outcomes for stroke patients: a comprehensive audit. Australian Journal of Physiotherapy, 43, 173-180.
Physiopedia. Gait Training in Stroke
Physiopedia. Gait image
Author: Jason Tendler