stretching

Examples of stretching in the following topics:

• Benefits of Stretching

  • Stretching is a form of physical exercise, where specific skeletal muscles are stretched, improving elasticity and muscle tone.
  • Stretching can strengthen muscles, and in turn strong muscles are important to stretching safely and effectively.
  • Stretching can be dangerous when performed incorrectly.
  • It is also suggested that one stretching exercise may not be enough to prevent all types of injury, and therefore, multiple stretching exercises should be used to gain the full effects of stretching.
  • Over-stretching or stretching to a point where pain is felt may be inappropriate and detrimental.

• Muscle Tone

  • Muscle tone is a measure of a muscle's resistance to stretching while in a passive resting state.
  • Spindles can also trigger impulses to the cerebral cortex providing information about the degree of stretch within the muscle.
  • If tone decreases and the muscle stretches the spindles trigger an impulse resulting in the contraction of the muscle.
  • With this contraction the spindle is no longer stretched and so stops triggering further contraction.
  • A similar system is found in the tendons attaching muscle to bone where distinct stretch receptors termed golgi tendon organs assess the level of stretch within the tendon.

• Hypotonia and Hypertonia

  • Hypertonia is the reduced ability of muscles to stretch due to increased muscle tension; hypotonia, due to chronic reduced muscle tension.
  • Hypertonia is a reduction in the ability of a muscle to stretch due to increased muscle tension; it is caused by lesions to upper motor neurons.
  • Dystonic hypertonia is the resistance to passive stretching in muscles, and the return of limbs to fixed positions after contraction.
  • The disruption of input from stretch receptors leads to decreased muscle innervation sensitivity, causing hypotonia.
  • Hypotonia is thought to be associated with the disruption of afferent input from stretch receptors and/or lack of the cerebellum's facilitatory efferent influence on the fusimotor system (the system that innervates intrafusal muscle fibers thereby controlling muscle spindle sensitivity ).

• Spinal Reflexes

  • Spinal reflexes include the stretch reflex, the Golgi tendon reflex, the crossed extensor reflex, and the withdrawal reflex.
  • The stretch reflex (myotatic reflex) is a muscle contraction in response to stretching within the muscle.
  • When a muscle lengthens, the muscle spindle is stretched and its nerve activity increases.
  • Although the tendon reflex is less sensitive than the stretch reflex, it can override the stretch reflex when tension is great, making you drop a very heavy weight, for example.
  • Like the stretch reflex, the tendon reflex is ipsilateral.

• Running Injuries

  • Stretching is often recommended as a requirement to avoid running injuries, and it is almost uniformly performed by competitive runners of any level.
  • Recent medical literature, however, finds mixed effects of stretching prior to running.
  • Another, however, has demonstrated that stretching prior to running increases injuries, while stretching afterwards actually decreases them.
  • Recent studies have also shown that stretching will reduce the amount of strength the muscle can produce during that training session.
  • Evaluate the methods (hydrotherapy, running surface, stretching, and technique) used to prevent running injuries

• Proprioceptor Regulation of Breathing

  • These stretch receptors are mechanoreceptors, which are a type of sensory receptor that specifically detects mechanical pressure, distortion, and stretch, and are found in many parts of the human body, especially the lungs, stomach, and skin.
  • During stretch receptor activation, the inhibitory signal that travels through the vagus nerve is also sent the sinus-atrial node of the heart.
  • The heart rate returns to normal during expiration when the stretch receptors are deactivated.
  • It is initiated either by stimulation of stretch receptors or stimulation of proprioceptors activated by lung deflation.
  • The vagus nerve is the neural pathway for stretch receptor regulation of breathing.

• Pulled Hamstring and Charley Horse

  • A strained hamstring, also known as a pulled hamstring, is defined as an excessive stretch or tear of muscle fibers and related tissue.
  • Straining of the hamstring , also known as a pulled hamstring, muscle pull, or Charley Horse is defined as an excessive stretch or tear of muscle fibers and associated tissues.
  • Grade 1 - A sensation of a cramp or tightness and a slight feeling of pain when the muscles are stretched or contracted.
  • It is confirmed by pain during stretch and contraction of the muscle.

• Injuries to Nerves Emerging from the Brachial Plexus

  • In most cases, the nerve roots are stretched or torn from their origin, since the meningeal covering of a nerve root is thinner than the sheath enclosing the nerve.
  • Although injuries can occur at any time, many brachial plexus injuries happen during birth: the baby's shoulders may become impacted during the birth process causing the brachial plexus nerves to stretch or tear.
  • The excessive stretch results in incomplete sensory and motor function of the injured nerve.
  • The severity of nerve injuries may vary from a mild stretch to the nerve root tearing away from the spinal cord (avulsion).
  • The brachial plexus may be injured by falls from a height on to the side of the head and shoulder, whereby the nerves of the plexus are violently stretched.

• Reflexes and Diagnosis

  • The stretch reflexes (often called deep tendon reflexes, though not to be confused with Golgi tendon reflexes) provide information on the integrity of the central nervous system and peripheral nervous system.

• Gastric Phase

  • Ingested food stimulates gastric activity in two ways: by stretching the stomach and by raising the pH of its contents.
  • Stretch activates two reflexes: a short reflex mediated through the myenteric nerve plexus and a long reflex mediated through the vagus nerves and brainstem.
  • The stomach stretches and churns while enzymes break down proteins.