Locomotor disability restricts the movement of limbs (legs and arms), limiting an individual’s ability to move from one place to another. This disability is typically associated with muscles, joints, and bones, and can cause difficulty in activities such as picking up objects, walking, and holding items.

Disorders Related to Movement and Locomotion

Below is a brief discussion of some disorders related to movement and locomotion:

Myasthenia Gravis

The disorder is characterized by quick exhaustion and weakness of any of the muscles under voluntary control. It is caused by mistakes in the transmission of nerve impulses to the muscles. This occurs when the normal communication between the muscles and the nerves is disrupted, at the neuromuscular junction - the location where the nerve cells connect with the muscles they control.

In this chronic autoimmune disorder, the antibodies destruct the communication between the muscles and nerves, leading to weakness of the skeletal muscles. This causes the gradual wasting away of the muscles and eventually leading to immobility. In the later stages, even the jaw muscles do not function, making it impossible for the person to eat. This disorder mainly affects the voluntary muscles of the body, particularly those which govern the mouth, eyes, limbs and throat.

Treatment can help to alleviate symptoms and signs such as double vision, weakness of leg or arm muscles, drooping eyelids, difficulty swallowing, chewing, speaking and breathing. Although this condition can affect people of all ages, it is more commonly seen in young women and men over the age of 60.

Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is a group of inherited diseases that cause progressive muscle weakness and muscle mass loss. Mutations in the genes involved in the production of proteins important for forming healthy muscles lead to the lack of the protein dystrophin, which is essential for normal muscle function. Without this protein, individuals can experience difficulty with swallowing, walking, and muscle coordination.

Muscular Dystrophy is caused by gene mutations which affect the production of muscle proteins. These mutations can be either inherited (autosomal recessive, X-linked recessive, or autosomal dominant) or occur spontaneously during early development. Additionally, some genes are responsible for producing proteins which protect the muscle fibers, and when one of these genes is defective, Muscular Dystrophy can occur at any age, although diagnosis is usually made in childhood. There are several varieties of Muscular Dystrophy, each of which is caused by a distinct genetic mutation. Most of these mutations are inherited.

Tetany

It is a disorder characterized by elevated neuronal excitability, usually associated with hypocalcemia. It is marked by the contraction of the distal muscles in the hands and feet, accompanied by a tingling sensation around the mouth and in the extremities. This involuntary muscle contraction can be caused by disorders that increase the frequency of action potentials in the nerves or muscle cells that innervate them.

The general cause of tetany is a calcium deficiency (hypocalcemia). Excess phosphate could also stimulate spasms. Underfunctioning of the parathyroid glands, low levels of carbon dioxide due to changes in the albumin binding calcium, and low levels of magnesium are all possible causes of tetany. Hyperventilation is a common cause of low carbon dioxide levels. There are also other causes which could trigger tetany.

Arthritis

In simple words, arthritis is the inflammation of the joints. This can be inflammation of one joint or multiple joints, and there are several types of arthritis with varying causes and treatments. Generally, it is characterized by tenderness and swelling of one or more joints, accompanied by stiffness and joint pain which usually worsens with age. The two most common forms of arthritis are osteoarthritis and rheumatoid arthritis.

Osteoarthritis causes the breakdown of cartilage, a slippery, hard tissue that covers the ends of bones where joints are formed. In contrast, Rheumatoid Arthritis is a condition in which the body’s immune system targets the joints, starting with the lining of the joints.

Osteoarthritis is a condition characterized by wear and tear damage to the cartilage of joints. The cartilage serves as a cushion between the ends of the bones, allowing for smooth joint movement. However, if the damage is severe enough, the bones can rub against each other, resulting in limited movement and pain. This type of damage can occur over a period of years, or it can be accelerated by an infection or a joint injury. It can also affect the entire joint, leading to changes in the bone structure and the breakdown of the connective tissue that attaches muscles to bones and holds the joints together. Additionally, it can cause inflammation of the joint lining.

The main goal of treatments for arthritis is to reduce symptoms and improve quality of life, depending on the type of arthritis.

Osteoporosis

Bone is a living tissue which is replaced and broken when the creation of new bones is not in sync with the loss of the old bone. This condition, known as Osteoporosis, affects bones and is derived from Latin meaning “porous bones”. In a healthy bone, the interior is composed of several tiny spaces similar to a honeycomb. However, Osteoporosis increases the size of these spaces, causing bones to become less dense and lose strength. Additionally, the exterior of the bone becomes thinner and weaker.

People with osteoporosis are at a heightened risk of suffering from broken bones or fractures when engaging in everyday activities. Osteoporosis causes bones to become brittle and weak, and even slight falls or pressure can lead to fractures. These fractures are usually found in the spine, wrist, or hip. Eating a nutritious diet and engaging in weight-bearing exercises may help to prevent bone loss or strengthen existing weak bones.

This condition, caused by a deficiency of calcium, softens bones. Vitamin D is necessary for the absorption of calcium, and women are particularly prone to this condition post menopause, as the female hormone estrogen mobilizes calcium and passes it to the bones. When there is a lack of estrogen, bones become brittle and prone to cracking and breaking.

Gout

Gout is a common form of arthritis that causes swelling, intense pain, and stiffness in the joints, typically affecting the big toe. It is caused by an excess of uric acid in the bloodstream, which is a product of the metabolism of proteins. Gout attacks can come on quickly and recur at regular intervals, and can eventually cause damage to the tissues in the areas of inflammation and extreme pain.

Signs and symptoms of gout typically manifest due to the formation of uric acid crystals in the joints. These gout attacks often occur without warning, particularly during the night, and are usually treated with specific medications.