Sense of movement, or muscle sense

The previous two senses, touch and the sense of life, observed the body's boundaries, the body's internal state and the space it takes up. The sense of movement, or of muscles, enables you to perceive your body's movements and posture. It is the third of the four bodily senses in Rudolf Steiner's scheme of twelve senses.

Perceiving movement and position

The body – limbs, eyes, mouth, tongue, forehead, chest – is never still. All these movements are perceived, and very accurately, too. You can perceive a 0.038 degree turn of the elbow. Beyond the movements themselves, you are also aware of the exact position of your limbs and all the other moving parts of your body. At any given moment, you know exactly where your arms and feet are.

This is essential information. Anyone who is going to execute a new movement has to know where the movement is to begin. You don't even have to think about this; the sense of movement is always present.

Its constant presence makes it easy to overlook. Speaking, chewing, blinking and breathing all involve small, finely coordinated movements that are perceived and adjusted continuously. A foot that has gone to sleep, or a jaw numbed after a visit to the dentist, suddenly shows how much depends on it. The limb is still there and can still be moved, but it feels strange and clumsy because the usual stream of information is missing.

The sense organs in muscles, tendons and joints

The muscle sense is situated in spindle-shaped receptors in the muscles, which measure the degree of tension in the muscle fibres. There are similar receptors in the tendons. The bending and stretching of the limbs is perceived by receptors in the joint tendons and in the surrounding tissue.

Physiology describes these organs in more detail. A muscle spindle consists of a few thin, specialised muscle fibres enclosed in a capsule, lying parallel to the ordinary muscle fibres. Sensory nerve endings are wound around them. When the muscle is stretched, the spindle is stretched too, and the nerve endings fire. The spindle has its own small motor nerve supply, so that its sensitivity can be adjusted while the muscle contracts. The receptors in the tendons, known as Golgi tendon organs, lie where muscle passes into tendon and register the force with which the muscle pulls.

The same organs take part in reflexes. When a doctor taps the tendon below the kneecap, the thigh muscle is briefly stretched, its spindles fire, and the muscle contracts: the knee-jerk reflex. Much of what the muscle sense perceives never reaches consciousness at all but is used directly to keep movements smooth and posture steady.

Physiology calls this whole field proprioception, a term introduced by the physiologist Charles Sherrington. In rare cases the sensory nerves that carry this information are damaged. The people concerned can still use their muscles, but they no longer know where their limbs are without looking. Every movement then has to be guided by the eyes, and in the dark they can hardly move at all. Such cases show how much the sense of movement normally does unnoticed.

Movement and the eyes

The sense of movement is primarily focused on perceiving the own body, but it is often also used to observe things around. In observing moving objects, the sense of movement works together with the sense of sight, so that you can see the type of movement taking place and estimate the speed of the moving object.

In order to determine an object's shape, the eyes follow the outline of the object and shift to and from details that attract attention. Painters use this roving habit of the eyes to guide the viewer through their painting along a chosen course. In this approach, the movements and shapes are observed by the movement sense in the eye muscles, but the eye itself only observes the colours. The page on the sense of sight describes the other side of this collaboration.

The eyes move in two ways. When they scan a still scene, they jump in quick steps from one point to the next; these jumps are called saccades. A smooth, gliding eye movement is only possible when the eyes follow something that itself moves, such as a bird in flight. Anyone can check this by trying to let the eyes glide slowly along the edge of a table: they will jump, not glide. Six small muscles move each eyeball, and their movements are perceived as precisely as those of the limbs.

Imitation and muscular imagery

You can also perceive the movement of a branch in a tree with the muscle sense, by imitating the movement with your arms. You could also imagine the movement, and imagine how your eyes or arms would likewise move. This is called sensorial fantasy or muscular imagery, and it can be applied whenever shapes and movements are to be observed and imitated.

Think about the gait of a horse, how a cow or a pig lies down, the motions of leaves, the arrangement of branches in different trees, and so on. A cow that lies down first goes down on its front knees and then lowers the hind part; when it gets up, the hind legs rise first. A horse does it the other way round and rises with the front legs first. Imitating both movements with the own body makes the difference felt, not only seen. The horse's walk, trot, canter and gallop each have their own rhythm, which can be followed in the same way; the pages on ungulates and odd-toed ungulates describe these animals further.

A pig lies down differently again. Pigs often rest flat on their side, with the legs stretched out, and in a group they like to lie pressed close against each other. A lying cow, by contrast, usually rests on its chest with the legs folded beneath it, ready to chew the cud. Such differences are easy to see, but they become meaningful only when they are felt in the own body.

Children learn a great deal through imitation long before they can explain what they are doing. They take over the way the adults around them walk, sit and gesture. In that sense, the sense of movement is also a way of taking in the world: the movement of another being is rebuilt, as it were, in the own body.

Movement in plants

Plants move too, but so slowly that the eye misses it. Shoots bend towards the light, roots grow downwards, and the tip of a climbing plant such as a bean or hop circles around until it finds a support to twine along. The leaves of clover and many beans fold up in the evening and open again in the morning. Time-lapse films make these movements visible, and suddenly the plant appears as active as an animal.

Without such films, the movement of a plant has to be read from its form. A branch shows the direction in which it grew; a curved trunk shows where the tree once had to find its way to the light. Following these lines with the eyes, or tracing them with the hand, is an exercise for the sense of movement. The finished form becomes a record of a movement, and the observer re-enacts that movement in a much shorter time.

Movement in speech

Speaking is one of the finest movements the body makes. The tongue, lips, jaw, soft palate and larynx work together in rapid, exactly timed patterns, and every sound has its own configuration. These movements, too, are perceived by the muscle sense, which is why a numbed tongue makes speech clumsy. Deaf children who learn to speak rely to a large extent on seeing and feeling these movements, since they cannot hear the result well or at all.

In anthroposophical literature on the twelve senses, the sense of movement is often paired with the sense of word, one of the senses directed at other people. The idea behind this pairing is that understanding speech involves an inner, unspoken following of the movements that produce it.

Movement and feeling

Movement and feeling are connected. This is evident in body language: the welcome indicated by open arms, the dismissal expressed by a throw-away wave of the hand, and so on. Joy tends to lift the body and widen its gestures, while sorrow makes it sink and draw in. The same connection works in the other direction. Walking upright with an open chest feels different from shuffling with a bent back.

For the phenomenological way of looking this is more than a curiosity. When the movement of an animal or plant is imitated, a feeling for its character arises at the same time. The heavy, rolling walk of a cow, the nervous scurrying of a mouse and the springy stride of a big cat express something of the nature of these animals. Describing that impression carefully, and checking it against the observable details, is part of the method.

The sense of movement among the bodily senses

In Steiner's scheme, touch, life, movement and balance form the group of senses directed at the own body. Touch perceives the boundary, the life sense the inner state, the sense of movement what the body does, and the sense of balance how the body stands in space. The four work together in every action: a person who walks across a room touches the floor, feels the effort, perceives the swing of the legs and keeps upright, all without paying attention to any of it.