Back Mechanics Review

True or False: Ligaments change position slowly during prolonged trunk flexion

True

True or False: Ligaments change shape during prolonged sitting

True

True or False: Muscles can cause back injury and pain

True

True or False: Muscles cause compression on the vertebra

True

True or False: Sit ups can cause disc herniation

True

True or False: Sitting causes disc herniation

True

True or False: The bird dog is a safe exercise for the back

True

Good Lifting Posture

Good lifting posture includes hip flexion with a neutral trunk or hip flexion, knee flexion, and ankle dorsiflexion with a neutral trunk

Is flexibility in the trunk high or low in those with back pain?

HIGH

Why is athletes sitting on the bench bad for the back?

Athletes who sit on the bench have back problems because after warming up they are sitting with poor posture for prolong periods until they are told to play and are relatively tall sitting in small chairs causing them to flex their trunk to compensate

How much load and how many repetitions are typically needed to cause back pain and injury?

A submax or low load and many repetitions over a period of time

Why are the instructions to lift with the legs not enough information?

Because no matter if you are bent over or have your chest up you are constantly lifting with your legs. People need to focus more on keeping their trunk in a neutral position.

3 Sources of Back Pain

Facet pain, lesions of annulus, and the sacroiliac joint

True or False: Back extension is always safe for the back

False

True or False: Back muscles improve their ability to produce rotary force during trunk flexion

False

True or False: Bending over at the hips without a change in knee or trunk motion is always bad lifting technique

False

True or False: Hip flexion with trunk flexion is the best method of lifting

False

True or False: The leg press is always a safe exercise for the back

False

Which causes more back pain, low back strength or low muscular endurance?

Low muscular endurance

What type of job reduces the risk of back pain?

Moderate activity

Which position reduces back injury, neutral vertebra or trunk flexion?

Neutral vertebra

What type of jobs cause disc herniation?

Sedentary jobs

What happens to the rotary force in the back muscles during trunk flexion?

Since the angle of the muscle has decreased during trunk flexion the muscle force has become more parallel (thus stabilizing) creating very little rotary force and movement ability in the back muscles

How long does it take for the disc to return to normal shape after an hour of sitting?

The disc takes about an hour for it to return to its normal shape after an hour of sitting

Describe what mechanical change happens to the disc during trunk flexion?

The discs become compressed unevenly resulting in one to move forward or anteriorly shear while the other posteriorly bulges out on the other side potentially causing an injury

What happens to the force arm of the muscle during trunk flexion?

The force arm is directed towards the stabilizing force

What supports the back during trunk flexion?

The posterior muscles support the back (here we want our back muscles to pull perpendicular with a rotary force)

What happens to the amount of trunk stabilization during trunk flexion?

There is TOO MUCH trunk stabilization during trunk flexion resulting in an uneven amount of compression on the discs

Can smoking increase the risk of back pain?

Yes, smoking can increase the risk of back pain by causing you to have trouble breathing or by coughing repeatedly

Can a sneeze or cough cause back injury?

Yes, sneezing or coughing while bent over can cause a back injury due to the core not being stabilized and the back being under stress

Who does sleeping tends to cause more back pain in, the young or the elderly?

Young