biology

Motor disorder

Motor disorder is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Motor disorder rather than just read about it. In short: Motor disorders are disorders of the nervous system that cause abnormal and involuntary movements. They can result from damage to the motor system.

Key takeaways

Motor disorder belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Motor disorder to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Motor disorder from memory before moving on to harder problems.

Reference excerpt

Motor disorders are disorders of the nervous system that cause abnormal and involuntary movements. They can result from damage to the motor system. Motor disorders are distinct from movement disorders. Motor disorders are defined in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) – published in 2013 to replace the fourth text revision (DSM-IV-TR) – as a new sub-category of neurodevelopmental disorders. The DSM-5 motor disorders include developmental coordination disorder (dyspraxia), stereotypic movement disorder, and tic disorders including Tourette syndrome.

Signs and symptoms Motor disorders are malfunctions of the nervous system that cause involuntary or uncontrollable movements or actions of the body. These disorders can cause lack of intended movement or an excess of involuntary movement. Symptoms of motor disorders include tremors, jerks, twitches, spasms, contractions, or gait problems. Tremor is the uncontrollable shaking of an arm or a leg. Twitches or jerks of body parts may occur due to a startling sound or unexpected, sudden pain. Spasms and contractions are temporary abnormal resting positions of hands or feet. Spasms are temporary while contractions could be permanent. Gait problems are problems with the way one walks or runs. This can mean an unsteady pace or dragging of the feet along with other possible irregularities. Through the process of several healthcare professionals can help in diagnosing motor disorders. Neurological examinations can be made to identify motor disorders. This can be done through MRI or CT or electromyography, which are tests done to evaluate the function of muscles and nerves.

Causes Pathological changes of certain areas of the brain are the main causes of most motor disorders. Causes of motor disorders by genetic mutation usually affect the cerebrum. The way humans move requires many parts of the brain to work together to perform a complex process. The brain must send signals to the muscles instructing them to perform a certain action. There are constant signals being sent to and from the brain and the muscles that regulate the details of the movement such as speed and direction, so when a certain part of the brain malfunctions, the signals can be incorrect or uncontrollable causing involuntary or uncontrollable actions or movements.

Risk factors The irregularity of body movements, such as tremors and jerking movements in the hands, arms, legs, and the head, including the face, can cause issues with coordination and balance. Issues with coordination and balance may cause stability problems that can lead to falls and injuries. Movement disorders can cause a decrease in pace within the body which can be exhausting and much harder for individuals to get by in their daily living.

References

Worked examples

Example 1 — a first encounter with Motor disorder

Start with the simplest possible case. Write down what Motor disorder claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Motor disorder before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Motor disorder ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Motor disorder

In research: Motor disorder appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Motor disorder in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Motor disorder is common in secondary-school and first-year university syllabi. It links to neighbouring topics Extrapyramidal and movement disorders, Neurodevelopmental disorders, Neurological disorders, so understanding it makes those chapters shorter.
In everyday life: Look for Motor disorder outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Motor disorder in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Motor disorder means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Motor disorder out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Motor disorder in simple terms?

Motor disorders are disorders of the nervous system that cause abnormal and involuntary movements. They can result from damage to the motor system.

Why does Motor disorder matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Motor disorder?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Motor disorder.