When the patient comes home from hospital, the first hurdle is often the stairs. Which leg should take the first step going up? And which leg goes first going down? This is not a minor matter. With the wrong order, the newly replaced knee has to take extra load, and the patient can easily lose balance.
In one sentence:going up, the "good leg" that was not operated on steps up first. Going down, the "bad leg" that was operated on goes down first. Physiotherapists often put it as "up with the good, down with the bad". In the early period, hold the handrail and start with one step at a time. The knee usually needs to bend to about 90 to 100 degrees for this movement (for the sequence see the NHS rehabilitation guidance).
How going up and going down stairs differ in what they ask of the knee
Going up and going down are not simply opposite directions. For a joint after knee replacement, the mechanical demands are quite different. Going up, the stronger good leg pushes the whole body up from the higher step, and the operated leg basically just follows. Going down is the opposite. The leg that steps down first has to keep bending the knee while the front thigh muscle slowly lowers the whole body, which is eccentric control (the muscle working while it lengthens). Measurements showed that about six months after a knee replacement, the peak moment, power and sagittal plane range of movement of the operated knee on stairs were still clearly lower than on the other side (Pozzi 2015). Another follow-up study found that stairs remain one of the most common residual functional problems after a knee replacement, and improve gradually as rehabilitation progresses (Unver 2014). The principle of the sequence is therefore very clear: whichever step needs force is given to the stronger side.
The order for going up stairs
The key to going up is "use the good leg for the effort and avoid forcing the operated leg". The order is as follows (in the early period it is suggested to hold the handrail with one hand and a crutch or walking stick with the other).
- Good leg up first—The good leg that was not operated on steps up to the higher step first and pushes the body up.
- Operated leg follows—Then bring the operated leg up to the same step. This leg just follows and does not have to take weight to push the whole body up.
- Crutch or stick last—Finally move the walking aid to the same step. Stand steady on each step first, and never hurry or skip steps.
The order for going down stairs
Going down stairs is often what patients fear most, because the operated leg has to bear weight eccentrically. The sequence is the reverse of going up.
- Crutch or stick down first—First place the walking aid on the lower step, to give support in front.
- Operated leg follows down—Keep the operated leg slightly bent and step down slowly to the lower step, so that the body's centre of gravity shifts slowly under control.
- Good leg down last—The stronger good leg stays on the higher step and steps down last, controlling how fast the whole body descends from above.
Why is going down so tiring and so frightening? The burden of eccentric control falls on the front thigh muscle of the operated leg, whose strength has not yet caught up with the other side in the short term. Research shows that going-down speed and ability are directly related to the quadriceps strength of the operated leg. Patients who rated their ability to rise from a chair better early after surgery had stronger knee extensors and went down stairs faster (Nyland 2007), which can serve as a simple indicator of readiness for going downstairs. To rebuild this strength in a planned way, see the training framework on recovering quadriceps strength after knee replacement.
The knee flexion angle needed for stairs
Even with the correct sequence, the knee must bend far enough to manage it. A measurement study using a flexible electrogoniometer found that level walking generally needs less than 90 degrees of flexion, while going up and down stairs and sitting down and standing up need about 90 to 120 degrees. The study also suggested setting the rehabilitation flexion target at about 110 degrees, which is enough for most daily activities (Rowe 2000). Until the flexion angle reaches this, do not force alternating legs.
| Level walking | Level walking generally needs less than 90 degrees of flexion. Being able to walk on the flat therefore does not mean the patient can already manage stairs (Rowe 2000). |
| Going up and down stairs / sitting and standing | Stairs need about 90 to 120 degrees of flexion, which asks clearly more of the joint than walking on the flat. If the angle is not enough, the joint feels stuck when going up or down, and it is hard to lift the leg or step down. |
| Rehabilitation target | Research suggests that flexion of about 110 degrees is already enough for most daily activities, and the patient does not have to push to the extreme angle to count as having reached the target (Rowe 2000). |
For the overall pattern of recovering flexion and how it is measured, compare with the page on the knee flexion needed for daily function. Movements such as squatting and kneeling ask for even more angle and are a separate topic. For details, see what to do if you cannot kneel or squat after knee replacement.
Moving from one step at a time to alternating legs
In the early recovery period, do not rush. The safest way to start is "one step at a time (step-to)". For each step up or down, both feet first meet on the same step and the patient stands steady before going on to the next. As quadriceps strength and confidence return gradually, the patient moves slowly to the alternating pattern of "one leg per step" (reciprocal, with one foot on each step and continuous movement without stopping). This transition timetable rests mainly on clinical consensus and estimates from several sources. Reaching smooth, natural alternating stairs often takes several months, and a switch should never be forced just because the patient has reached a certain week after surgery.
Early stage: one step at a time (step-to)
- On each step, both feet meet on the same step and stand steady before going up or down to the next
- Keep the order of "good leg up, bad leg down" throughout
- One hand on the handrail and the other with a crutch gives the steadiest double support
Advanced stage: alternating (one leg per step)
- One foot on each step, going up and down continuously without stopping on every step
- Only switch to this pattern once the quadriceps is strong enough, the flexion angle has been reached and the patient feels confident
- It should be assessed by the physiotherapist from joint angle and muscle strength, and not decided by the number of days since surgery alone
Stair climbing can itself serve as a rehabilitation exercise (progressive loading and control practice) and not just as an assessment measure. However, high-quality research evidence for it as a stand-alone intervention is still limited, and clinically it is mostly done together with other exercises (Gavin 2017). General rehabilitation guidelines after surgery also include stairs in a step-by-step framework for rebuilding function (Mistry 2016). To see when the patient can move on from managing stairs to other daily activities such as driving and returning to work, return to the overview on criteria for returning to daily life and sport after knee replacement.
Coping with steep tenement stairs and narrow public housing stairs in Hong Kong
The actual stairs in Hong Kong homes are often harder to deal with than the standard practice stairs in a clinic. Before going home from hospital, it is best to prepare for each of the following.
- Most tenement buildings have no lift, and the stairs are narrow and steep, with high, deep steps, and the handrail may be on one side only or even loose. In the first few weeks after surgery, it is best to have a family member with the patient when using the stairs, to use the "one step at a time" method, and to slow down especially when going down
- Public or subsidised housing flats may have a threshold step at the door or stairs between levels, and narrow corners often leave no room for crutches. It is suggested to plan the route in advance as "one hand on the wall and one hand on the handrail"
- Before discharge, count how many steps there are from the front door to the bedroom and which stretch has a handrail. If some steps on the way have no handrail, consider sleeping in the living room for the time being or changing the route at home, to avoid going down the stairs to the toilet in the dark at night
- While the joint angle or muscle strength is not yet enough, never force alternating legs, or hurry and skip steps because of time pressure
To check the registration of a home visit physiotherapist, visit the website of the Physiotherapists Board (https://www.smp-council.org.hk/pt/). For patients who had surgery in a public hospital orthopaedic department, referral to community rehabilitation after surgery is generally arranged through the orthopaedic department of the original hospital or the Hospital Authority (https://www.ha.org.hk).
When to ask a physiotherapist for help with stairs
If the patient is stuck at the stairs, for example not daring to go down, feeling the operated leg is too weak to support the body, or unsure whether the joint angle is enough to switch to alternating steps, professional assessment should be sought. On a home assessment, the physiotherapist teaches the sequence on the patient's own real stairs and not on the standard steps of a clinic. Step height, depth and handrail position differ on every staircase in tenement and public housing buildings, and practising in the real living environment is the way to move safely to managing independently. The therapist also measures the knee flexion angle and thigh strength on the spot, to judge whether the day's session should continue with "one step at a time" or can begin to try alternating steps, and whether a crutch or stick is still needed, so that a fall does not follow from forcing a switch just because enough days have passed. The move from step-to to alternating steps depends on angle, strength and confidence, and not on which week after surgery the patient has reached. This is clinical consensus and needs checking at each visit. The home physiotherapy provided by Nova Health's registered physiotherapistsadjusts the pace of training and the aids according to the patient's knee condition at the time and the actual stairs at home. Official guidance gives the basic principles of sequence (good leg up, bad leg down, use the handrail), and the fine-tuning in practice depends on assessment at each visit.