Topic 5

Amyotrophic lateral sclerosis (ALS)

"Lou Gehrig's Disease" is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body. The progressive degeneration of the motor neurons in ALS eventually leads to their death. When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed. Early symptoms of ALS often include increasing muscle weakness, especially involving the arms and legs, speech, swallowing or breathing. When muscles no longer receive the messages from the motor neurons that they require to function, the muscles begin to atrophy.

Anatomical Terms of Motion

Flexion Extension Abduction Adduction Circumduction Rotation

Transverse Plane Movements Medial and Lateral Rotation

Transverse plane movements mostly involve rotation around the long axis of the body segment. When the head or trunk rotate from side to side, the movement is simply called left or right rotation. Rotation of an arm or a leg in the transverse plane is called medial rotation if the rotation is directed medially, or inward, and lateral rotation if the movement is directed laterally, or outward.

Frontal Plane Movements Lateral Flexion

Trunk and neck motions away from the anatomical position in the frontal plane are called lateral flexion and side bending. Return from a position of lateral flexion to anatomical position is called lateral extension.

Head & Neck Muscles

Usually grouped into three categories-facial muscles, chewing muscles, and neck muscles Facial Muscles Frontalis Orbicularis oculi Orbicularis oris Buccinator Zygomaticus

Rotation

Bone revolves around its own longitudinal axis

Hernia

A balloon-like section of the abdominal cavity lining that protrudes through a hole or weakened section of the muscle in the abdomen. Can be caused by heavy lifting or by any activity or medical problem that increases pressure inside the abdominal cavity.

Contusion

A bruise or bleeding within a muscle, resulting from impact. When an already injured muscle is repeatedly struck a more serious condition, called myositis ossificans, can develop. It involves the formation of a calcium mass-after about 6-7 wks the body will generally begin to absorb, but bony lesions can remain in the muscle.

Multiplanar Movements Pronation and Supination

A few movements of body segments do not fall within a single plane. Pronation at the subtalar joint (where the ankle bones meet) is a combination of eversion, abduction, and dorsiflexion. Supination at this joint includes inversion, adduction, and plantar flexion.

Muscle Functions Behavioral Properties

All muscle tissues have four behavioral characteristics in common: irritability, extensibility, elasticity, and contractility. Two of these-extensibility, the ability to be stretched, and elasticity, the ability to return to normal length after a stretch-are common not just to muscle, but to many types of biological tissues. The stretched muscles do not return to resting length immediately, but shorten over a period of time.

Who Gets Tendinitis?

Anyone can get tendinitis, but it is more common in adults, especially those over 40 years of age. As tendons age they tolerate less stress, are less elastic, and are easier to tear.

Cardiac Muscle

Cardiac Muscle: Muscles that form a network to make up the heart. Cardiac muscle cells are branched, cross-striated, and involuntary. Cardiac cells are arranged in an interconnected network of figure-eight or spiral shaped bundles that join together at structures called intercalated discs. This arrangement enables simultaneous contractions of neighboring cells to produce the heart beat.

Frontal Plane Movements Abduction and Adduction

Common movements in the frontal plant include abduction and adduction. Movements at the shoulder and hip that take the arm and leg away from the midline of the body are called abduction. Oppositely directed movements that bring the arm and leg closer to the midline of the body are called adduction.

Flexion

Decrease in angle between connecting bones

Delayed-Onset Muscle Soreness (DOMS)

Delayed onset muscle soreness (DOMS) describes a phenomenon of muscle pain, muscle soreness or muscle stiffness that occurs 1-2 days after exercise. This is a normal response to unusual exertion and is part of an adaptation process that leads to greater stamina and strength as the muscles recover This sort of muscle pain is not the same as the muscle pain or fatigue you experience during exercise. DOMS is also unlike the acute, sudden and sharp pain of an injury such as a muscle strain that occurs during activity and often causes swelling or bruising.

Naming Skeletal Muscles

Direction of muscle fibers: Some named in reference to an imaginary line, usually the midline of the body or the long axis of a limb bone Rectus= straight Oblique= slanted Relative size of the muscle: Terms such as maximuus, minimus and longus are often used in name Gluteus maximus Location of the muscle: Many muscles are named for bones with which they are associated Temporalis and frontalis Number of origins Biceps, triceps, and quadriceps: can assume that muscle has two, three, or four origins respectively. Location of the muscles origin and insertion: Occasionally muscles are named for their attachment points Sternocleidomastoid muscle Shape of the muscle: Some muscles have a distinct shape that helps with their identification Ex: Deltoid means triangular Action of the muscle Ex: flexor or extensor (flexes or extends a bone)

Circumduction

Distal or far end of a limb moves in a circle

Frontal Plane Movements Radial Deviation and Ulnar Deviation

Frontal plane movements of the hand at the wrist are called radial deviation and ulnar deviation. From the anatomical position, abduction of the hang toward the thumb is called radial deviation, and adduction of the hand toward the little finger is called ulnar deviation.

Extension

Increase in angle between connecting bones

Muscle Functions Tension and Types of Skeletal Muscle Contractions

It is the versatility of the arrangements of human muscles in agonist and antagonist pairs around joints that enables the different movements of the human body. These versatile arrangements also help to stabilize joints and maintain body posture.

Muscle Diseases (Myopathy)

Many different types, muscle fibers do not function normally for many different reasons resulting in weakening of muscles. Muscular Dystrophy (MD) a group of similar, inherited disorders, characterized by progressively worsening muscle weakening and loss of muscle tissue. Vary in severity, onset, groups of muscles affected, and rate of effect. No known cure; Goal is to control symptoms.

Duchenne Muscular Dystrophy

Most common and serious form of muscular dystrophy. Almost exclusively in males. Onset between 2 and 6, begins in extremities, usually only live to young adulthood. Disease progresses from extremities upward, finally affecting the head and the chest muscles.

Abduction

Movement of bone away from body midline

Adduction

Movement of bone toward midline

Multiplanar Movements Circumduction and Opposition

Moving a finger, arm, or leg in a rotational manner such that the end of the segment traces a circle is called circumduction. Touching you four fingers to the thumb is known as opposition.

Tetanus

Prolonged contraction of skeletal muscle fibers. Infection generally occurs through wound contamination and often involves a cut or deep puncture wound. As the infection progresses, muscle spasms develop in the jaw (thus the name lockjaw) and elsewhere in the body. Bacteria such as C. tetani and botulism interfere with ability to break down acetylcholine. Can lead to complete tetanus, and death

Strains

Muscle strain occurs when a muscle is stretched beyond its usual limits. Classified as Grade I, II, or III: Grade I (mild)-tightness in muscle day after injury Grade II (moderate)-strain produces pain caused by a partial tear, associated weakness and temporary loss of function. Grade III (severe)-involves tearing of muscle, loss of function, internal bleeding, and swelling. Hamstring strains are a problem for athletes because they are slow to heal and tend to recur. One-third of all hamstring strains will recur within the first year of returning to a sport or an activity. **The term strain (to muscles or tendons) and sprain (to a ligament at joint) are very similar. Remember that Tight muscles and Tendons gets sTrains.

Muscle Development

Newborns have only gross reflex muscle action because the nervous system must mature before the baby can control muscles. Motor control is acquired from head down, and proximal to distal.

Myasthenia gravis

Onset-adulthood Symptoms- drooping of eyelids, difficulty swallowing and talking, and generalized muscle weakness and fatigue. Disease involves a shortage of acetylcholine (ACH) receptors, blood contains antibodies to ACH receptors, suggesting it is an autoimmune disease. Death usually occurs as a result of the inability of the respiratory muscles to function, called respiratory failure.

What Are the Symptoms of Tendinitis?

Pain at the site of the tendon and surrounding area. Pain may gradually build up or be sudden and severe, especially if calcium deposits are present. Loss of motion in the shoulder, called "adhesive capsulitis" or frozen shoulder.

Sternocleidomastoid

Paired muscles (one of each side of the neck) are two-headed (origin at sternum and clavicle). The heads fuse before inserting into the mastoid process of the temporal bone. Action: Flexion of head. When both contract together, they flex your neck (action of bowing the head led some to call these "prayer" muscles). Rotation of head toward opposite side of contraction. If just one of them contracts, the head is rotated toward the opposite side

Platysma

Platysma-A single sheet like muscle that covers the anterolateral (front and sides) neck. Originates from the connective tissue covering of the chest muscles and inserts into the area around the mouth. Action: Pulls the corners of the mouth down (inferiorly), producing a downward sag of the mouth AND opens mouth widely.

Functions of the Muscular System

Provides movement in conjunction with the skeletal system Despite the different properties of the three types of muscle, certain behavioral characteristics are common to all muscle tissue. In the case of skeletal muscles, there are also certain functional roles that muscles can play in contributing to different movements of the body.

Treatment Tips for Shin Splints

Shin splints often heal on their own. You may also need X-rays or bone scans to look for fractures. Rest your body. It needs time to heal. Ice your shin to ease pain and swelling. Do it for 20-30 minutes every 3 to 4 hours for 2 to 3 days, or until the pain is gone. Anti-inflammatory painkillers. Arch supports for your shoes. Range-of-motion exercises Neoprene sleeve to support and warm your leg. Physical therapy to strengthen the muscles in your shins. Rare cases need surgery, such as if you have a severe stress fracture that caused your shin splints.

Skeletal Muscle

Skeletal Muscle: Attaches to bones and are largely responsible for body movement. Also known as striated muscle (due to prominent cross-stripes-or striations) and voluntary muscle . This is a majority of the muscle tissue in your body. An individual skeletal muscle cell is referred to as a muscle fiber because of its thread-like shape. Muscle fibers include many nuclei and vary in length and diameter. Some fibers run the entire length of a muscle, others are shorter. Skeletal muscle is highly organized. The cell membrane of muscle fiber is called the sarcolemma. Over the sarcolemma of each fiber is a fine, protective sheath of connective tissue called an endomysium. Groups of muscle fibers are bundled together by strong fibrous membrane called a perimysium into a unit known as a fascicle. All of the fascicles of a muscle are enclosed by a thick, tough connective tissue called an epimysium. The epimysium connects at both ends of the muscle with either a tendon or with a flat, sheetlike aponeurosis.

Tendinitis

Tendinitis (also called tendonitis) is an inflammation or irritation of a tendon, a thick cord that attaches bone to muscle.

Smooth Muscle

Smooth Muscle: Small, spindle-shaped, nonstriated, involuntary muscle tissue found in the walls of internal organs (stomach, intestines, urinary bladder, respiratory pathways) and the blood vessels. Also known as visceral muscle. The coordinated, alternate contracting and relaxing of smooth muscles changes the size and shape of the organ. During digestion, food is propelled by a wave of symmetrical squeezing of the walls of the digestive tract in a process called peristalsis. Controlled by the autonomic nervous system. Unlike skeletal muscle, smooth muscle can sustain contraction for long periods of time without becoming fatigued.

Where Does Tendinitis Occur?

Tendinitis can occur in almost any area of the body where a tendon connects a bone to a muscle. The most common places are: Base of the thumb, Elbow, Shoulder, Hip, Knee, Achilles tendon Overuse or doing too much too soon when the tendons are not used to a movement or to the task taken on. Tendinitis is common in "weekend warriors," people that play and exercise hard only on weekends. Occasionally an infection can cause tendinitis, especially infection from a cat or dog bite to the hand or a finger.

What Causes Tendinitis?

Tendinitis is most often caused by repetitive, minor impact on the affected area, or from a sudden more serious injury. There are many activities that can cause tendinitis, including: Gardening, Carpentry, Painting, Tennis, Golf, Throwing and pitching, Incorrect posture at work or home or poor stretching or conditioning before exercise or playing sports also increases a person's risk.

What is the Achilles tendon?

The Achilles tendon connects the calf muscle to the heel bone. It is the biggest tendon in the human body and allows you to rise up on your toes and push off while walking or running.

Muscular Dystrophy

The muscles enlarge due to fat and connective tissue deposit, but the muscle fibers degenerate and atrophy. The more severe types begin in childhood and some types can lead to a shortened life; others cause little disability. Symptoms: intellectual disability, delayed development of motor skills, frequent falling, drooling, and drooping of the eyelids. Some forms also affect the heart muscle, resulting in an irregular heart beat.

Sagittal Plane Movements

The primary sagittal plane (forward/backward) movements are flexion, extension, and hyperextension.

Directional Motions

The sagittal plane is in line with forward and backward motions; The frontal (coronal) plane is in line with sideways movement; and Rotational movements occur in the transverse plane.

Transverse Plane Movements Pronation and Supination

The special terms used for rotation of the forearm are pronation for medial (palm down) rotation and supination for lateral (palm up) rotation.

Trunk Muscles

The trunk muscles serves as a protective sheath for the organs of the thoracic and abdominal cavities. They provide stability for the vertebral column and are also responsible for maintaining upright posture. Collectively, trunk muscles enable flexion, extension, hyperextension, lateral flexion, and rotation of the head and trunk.

Shin Splints

They can be caused by: Irritated and swollen muscles, often from overuse Stress fractures , which are tiny breaks in the lower leg bones. Pronation or ''flat feet" -- when the impact of a step makes your foot's arch collapse Shin splints are very common. Runners might get them after ramping up their workout intensity, or changing the surface they run on -- like shifting from a dirt path to asphalt. Shin splints are also common in dancers.

Muscle Functions Tension and Types of Skeletal Muscle Contractions

When a skeletal muscle develops tension, one of three actions can happen: the muscle can shorten, remain the same length, or actually lengthen. When the biceps muscle develops tension and shortens, your hand moves up toward your shoulder. This is called a concentric, or shortening, contraction of the biceps. In this case, the biceps are performing a role of agonist, or prime mover, and the opposing muscle group, the triceps, are playing the role of antagonist. The antagonist muscles may be completely relaxed or may develop a slight amount of tension, depending on the requirements of the movement.

Muscle Functions Production of Heat

Working muscles generate heat. Even when we are not exercising (working) the muscles, typically comprising at least 40% of body mass, generate heat, and this heat helps maintain normal body temperature. Muscles require energy in the form of ATP to function. Recall that ATP is generated within muscle cells. The ATP is then released to provide energy when the muscle is stimulated, generating heat in the process.