1. sharp
   muscular
2. temporary

Although back pain is usually muscular in nature, the cause can also be related to the bones of the spine.

1. 23
   33
2. 43

There are 33 bones in the spine; 24 vertebrae, 5 sacral vertebrae fused together and 4 coccyx vertebrae fused together. The spine extends from the neck to the pelvis and includes four regions know as the cervical, thoracic, lumbar and sacral regions.

1. calcium and phosphate
   calcium and magnesium
2. sodium and phosphate

Bones primarily get their strength from calcium and phosphate.

1. exercise
   inactivity
2. dairy foods

Inactivity can cause the bones to become brittle. It is important to do weight-bearing activity in order to keep your bones strong.

1. an onion
   an orange
2. a pomegranate

The intervertebral disks are made from tough rings of cartilage, a fibrous elastic material. If you cut a disc horizontally it would resemble an onion. In the center of the disk there is a thick, jellylike fluid which acts as a shock absorber for the spine.

1. The disk pops out from between the vertebrae.
   Fluid has begun to leak through the disk rings.
2. The rings have completely torn and fluid has leaked.

A slipped disk refers to the leaking of fluid from the center of the intervertebral disk through some of the cartilage rings. When the rings tear to the point that there are only a few rings left intact it is called a bulging disk. When all the rings have torn completely and fluid leaks out it is called a ruptured or herniated disk. Bulging and herniated disks can press on the spinal cord and on the surrounding nerves causing back pain.

1. 0.5
   0.7
2. 0.9

About 70 percent of an intervertebral disk is made up of water when you are 20 years old. As you age, the disks slowly lose water and may dry out, forcing the spinal bones closer together. This may lead to pinching of nerves that run in between the vertebrae and can also cause the bones to rub against each other and wear out.

1. to hold the spine together
   to prevent nerve pinching
2. to allow for safe movement

Ligaments are bands of connective tissue that are somewhat elastic. Their main function in the spine is to allow for safe movement. They do this by being elastic enough to allow movement but their elasticity is limited enough that they will become taught and limit the movement of the spine within a safe range.

1. shortened muscles
   small muscles
2. lengthened muscles

Muscles contract and shorten when you move and lengthen and relax back into resting position. If muscles become fatigued they cannot relax properly and become tight. This may hold bones in the spine closer together causing pain, in addition to limiting your flexibility.

1. the brain
   the spinal cord
2. the nerve roots

The nervous system begins in the brain. It branches out through the spinal cord through nerve roots which branch into smaller nerves that innervate the peripheries of the body.

1. chemical
   mechanical
2. electrical

Tiny electrical signals pass along the nervous system, transferring messages from the brain to the body and vice versa via the spinal cord.

1. standing
   lying
2. sitting

Lying down with the back's curve naturally aligned is the most comfortable position for the back.

1. 30 degrees
   45 degrees
2. 60 degrees

You should limit your forward bending to about 30 degrees.

1. exercise
   rest
2. stretch

Resting gives your back a chance to heal. Lie down on a firm surface and place pillows under your knees to relax the spine and under your neck for comfort. Remember that too much rest can be harmful to your back. After a couple of days' rest, start exercising slowly to help keep your muscles and bones strong.

1. Apply ice to the area.
   Rest your back.
2. Exercise your back muscles.

Immediately after an injury occurs, blood rushes to the area to aid healing. However, this causes inflammation in the area and can add to the pain. Applying ice constricts the blood vessels and reduces inflammation.

1. 12 hours
   24 hours
2. 48 hours

It is recommended to avoid applying heat to your back, including hot showers, heat pads or lotions that create heat, for at least 48 hours after the injury has occurred. This reduces swelling and inflammation. Instead, use ice or cold compresses once an hour for 48 hours post injury for no more than 15 minutes at a time.

1. massage
   stretching
2. both of the above

Both stretching and a light massage help to relax muscles, opening blood vessels which bring nutrients to the muscles and remove waste from the muscles. It is a good idea to alternate the application of heat or cold with stretching.

1. unloading groceries
   resting
2. watching TV

Avoid stressful and strenuous activities for your back including heavy lifting, twisting, bending and turning.

1. Sit on soft couches.
   Take analgesia.
2. Lift heavy objects.

Over-the-counter analgesia can be an effective way to reduce back pain. But always make sure you check with your doctor which medications are safe for you to take. Couches may look comfortable, but they are unsupportive for your spine and promote poor posture, causing more damage to your back.

1. immediately after injuring yourself
   after a few days with no improvement
2. when pain is easing

Generally you should wait two or three days before seeing a doctor. However, if after a few days there is no improvement you should see a doctor. If you lose bowel or bladder control or experience numbness, tingling, or other similar sensations that run down an arm or leg or around the chest, inform your doctor.