When an older adult comes to physiotherapy with knee pain, poor balance, difficulty walking or trouble getting out of a chair, it can be tempting to focus on the obvious problem: the knee hurts, so assess the knee; the legs feel weak, so test strength; balance is poor, so practise standing exercises.
These things matter, but they are only part of the picture. Movement depends on several systems working together — including joint movement, strength, sensation, pain, confidence, reaction time and the ability to respond when something unexpected happens.
That is why our physiotherapy assessments focus on how the whole movement system is working, rather than measuring only one painful joint or weak muscle.
Key points
- We begin with the real-life task the person needs or wants to perform.
- We identify which physical, sensory and behavioural factors may be limiting that task.
- We test whether changing a suspected limitation actually improves the movement.
- The findings guide what should be trained next.
Movement is a whole-body problem
Consider getting out of a chair. To stand successfully, a person needs enough movement through the ankles, knees and hips; sufficient leg strength and power; awareness of their body position; the ability to shift weight forward at the right time; and enough balance to generate force without losing control.
If one part of the system is not working well, another part may compensate:
- limited ankle movement may lead to greater trunk lean or heavy use of the arms;
- knee pain may shift more weight onto the opposite leg; and
- reduced sensation through the feet may increase reliance on vision.
These compensations are not necessarily wrong. They are often the body's way of finding another solution. The important question is whether those solutions are still working well enough.
We call this Sensorimotor Reserve
Sensorimotor Reserve is the movement capacity a person has available beyond what they need for the task in front of them.
Someone with good strength, sensation, flexible movement options, fast reactions and good balance may tolerate small problems without losing function. As several changes accumulate, however, that reserve may narrow.
An older adult might have slightly reduced ankle movement, some loss of sensation under the feet, lower leg strength, slower reactions, knee pain and reduced confidence after a previous fall. None of these factors alone necessarily explains the difficulty. Together, they may leave very little spare capacity when the person needs to respond quickly.
That reduced reserve may not appear while the person stands quietly in a treatment room. It may become obvious when stepping off a kerb, turning quickly, walking on uneven ground or recovering after a trip.
This changes what we assess
Our assessment begins with an important question:
What movement is actually difficult for this person?
That might be walking, standing from a chair, climbing stairs, turning, getting into bed, stepping, reaching, getting off the floor or recovering balance.
We observe how the person performs the task, including:
- how quickly they move and whether they hesitate;
- whether they use their arms or external support;
- whether one side is doing more work;
- where movement is lost;
- how pain affects the task; and
- what happens as the task becomes more difficult.
Only then do we work backwards to determine what may be contributing.
Range of motion is not just a number
Recording how many degrees a joint can move remains useful, but the more meaningful clinical question is:
Does this person have enough movement for the task they are trying to perform?
Limited ankle movement may be relatively unimportant for someone with excellent strength, balance and reaction time. The same restriction may matter greatly for someone who already has reduced strength and sensation and therefore has fewer alternatives available.
Strength is also more than a number
A muscle may test weak because it has lost capacity. Pain, swelling around a joint and altered sensory information can also influence how effectively the nervous system activates that muscle.
This is why our clinicians look at how strength is expressed during movement, not simply whether a muscle receives a particular score. For some people the priority is building muscular capacity. For others, existing capacity may be difficult to access because movement is painful or the joint is not moving comfortably. Often both are present.
Balance testing should find the threshold
Standing still for 30 seconds tells us something about balance, but not everything. Everyday balance becomes harder when the feet are closer together, the surface or lighting changes, the head moves, attention is divided, the person reaches, a quick step is required or an unexpected disturbance occurs.
Our clinicians may therefore alter the task gradually to understand where balance begins to deteriorate. Two people may both appear stable during easy testing, yet one may lose stability quickly as the task becomes more demanding. That difference can be clinically important.
We also test whether a problem can be changed
One of the most useful parts of physiotherapy assessment is determining whether a suspected limitation actually contributes to the movement difficulty.
- Test the task: observe the chair rise, walk, step or other meaningful movement.
- Treat a suspected limitation: use a short, appropriate intervention — for example, to improve ankle movement.
- Retest the same task: look for a meaningful change in comfort, control, support or strategy.
If ankle movement improves but the chair rise is unchanged, the restriction may not be the main limitation. If the task becomes noticeably easier, that provides useful information about what may be influencing it.
This test–treat–retest approach helps keep treatment linked to function.
The assessment should lead directly to treatment
The purpose is not to make physiotherapy assessments longer or more complicated. It is to make them more meaningful.
Instead of collecting a list such as “weak legs, stiff ankle, poor balance”, we want to understand:
- What is this person trying to do?
- What is limiting them?
- Which limitations can we change?
- Does changing them improve the movement?
- What should be trained so the improvement becomes more durable?
Ageing rarely involves only one system. Effective rehabilitation therefore needs to consider how joints, muscles, sensation, balance, pain, confidence and movement work together.
That is why our assessment starts with the person and the movement they need — not simply the diagnosis written on the referral.