1. Biomechanics of the Spine & Hip
Movements of Spine
Flexion, Rotation, Extension, Abd, Add.
Hip Movements
Elevation, Anterior & Posterior Tilt, Flexion, Extension, Abd, Add, Hyperext, Hyperflex

2. Spinal Deviations
Lordosis
Kyphosis
Scoliosis

3. Forces Acting On The Spine
Forces Acting On The Spine Include:
Body Weight
Tension In The Spinal Ligaments
Tension In The Surrounding Muscles
Intraabdominal Pressure
The Major Form Of Loading On The Spine Is:
Axial

4. Upright Position Spinal Compression When Standing Upright
Resulting From:
Body Weight + Weight Held by Arms and Hands
When Standing Upright
Total Body Center of Gravity Is Anterior to the Spinal Column.
Spine Is Placed Under Constant Forward Bending Moment.

5. Torque
Defined: The Rotary Effect of a Force About An Axis of Rotation, Measured as the Producer of the Force and the Perpendicular Distance Between the Force’s Line of Action And The Axis
To Maintain An Upright Position
Torque Is Counteracted by Tension in the Back Extensor Muscles.

6. Spinal Muscles Role In Lifting
Spinal Muscles Have Small Moment Arms With Respect To the Vertebral Joints.
Have To Generate Large Forces To Counteract the Torque Produced About the Spine by Body Weight and Objects Being Lifted.
Erector Spinae
Muscles

7. Why Lift With The Legs?
Back Muscles, With a Moment Arm of Approximately 6 cm, Must Counter The Torque Produced by the Weights of the Body Plus Any External Loads.

8. Question: How Much Torque Is Developed By The Erector Spinae Muscles With a Fm 6 cm?
1 lb. = Newtons
Segment Weight Moment Arm
Head 13 lbs. (58N) 25 cm
Trunk lbs. (328N) 10 cm
Arms 18.2 lbs. (81N) 20 cm
Box lbs. (111N) 40 cm
Torque at L5-S1=
(328N)(10cm) + (81N)(20cm) + (58N)(25cm) + (111N)(40cm)
= ?
10,790 Ncm
Force?
0 = (Fm)(6cm) - 10,790 In static position, sum
of the torques acting at any point is zero.
Fm = N or ( lbs.)

9. Problem for a 135 lb. Person Torque ? 10,285 Ncm
How much force must be developed by the erector spinae with a moment arm of 6 cm. From the L5-S1 joint center to maintain the body in a lifting position with segment moment arms as Specified?
Segment Weight Moment Arm
Head 50 N 22 cm.
Trunk 280 N 12 cm.
Arms 65 N 25 cm.
Box Lifted 100 N 42 cm.
Torque ?
10,285 Ncm
Fm = 1714 N or (393 lbs. Force)

10. What Does The Research Show?
% Load Compression On L3 During the Upright Standing, Lying Down, and Sitting.
Compression Increases More with Spinal Flexion, and Increases Still Further with a Slouched Sitting Position.

11. Common Injuries Of The Back
Low Back Pain
Soft Tissue Injuries
Acute Fractures
Stress Fractures
Disc Hernia ions
Whiplash Injuries

12. Low Back Pain
75%-80% of Americans Experience Low Back Pain Sometime During Life.
Second Only to the Common Cold In Causing Absence In The Workplace.
Mechanical Stress & Psychosocial.

13. BACK, SPINAL COLLUMN, NECK
VERTEBRAL COLLUMN
RIBS & STERNUM

14. SPINAL COLLUMN 7 CERVICAL VERTEBRAE 12 THORACIC 5 LUMBAR
1 SACRUM - FUSED
1 COXCYC - 2 FUSED

15. JOINTS OF THE VERTEBRAL COLLUMN
VERTEBRAL JOINTS
GLIDING JOINTS - SLIGHTLY MOVABLE
SEPARATED BY INTERVERTEBRAL DISKS

16. THORACIC COMPLEX - RIBS
12 SETS OF RIBS
ARTICULATE WITH THE THORACIC VERTEBRAE AND STERNUM
7 PAIRS OF TRUE RIBS - ATTACH DIRECTLY TO STERNUM
5 PAIRS OF FALSE RIBS
2 PAIRS OF FLOATING RIBS
3 PAIRS ATTACH TO STERNUM VIA COSTOCHONDRAL CARTLILAGE

17. STERNUM
MANUBRIUM
BODY
XIPHOID PROCESS

18. MUSCLES OF THE BACK, NECK & ABDOMEN
DEEP POSTERIORS
ABDOMINALS
VERTEBRALS
SUPERFICIAL NECK MUSCLES

19. DEEP POSTERIORS
MOVEMENT - ROTATION, EXTENSION OF SPINAL COLLUMN

20. ABDOMINALS TRANSVERSE ABDOMINUS - DEPRESSION OF ABDOMEN
RECTUS ABDOMINUS - SPINAL FEXION
INTERNAL / EXTERNAL OBLIQUES - ROTATION, LATERAL FLEXION (ABDUCTION - ADDUCTION)

21. MUSCLES OF THE THORAX
DIAPHRAM
INTERNAL INTERCOSTALS
EXTERNAL INTERCOSTALS

22. INJURIES TO LOWER SPINE, PELVIS, HIP - CAUSES
DISK DEGENERATION - Herniation or General Degeneration
JOINT DISFUNCTION - Sacroiliac
Usual Cause - Lack of Normal Movement - Often Disputed
STRETCHED OR STRAINED LIGAMENTS - ie: Supraspinous Ligaments
LACK OF STRENGTH
Hamstrings, Erector Spinae, Abdominals, Hip Flexors

23. PREVENTION OF INJURIES TO BACK
POSTURE - STANDING
HYPERLORDOSIS
KYPHOSIS
POSTURE - SITTING
CAUSING PAIN TO LUMBO/SACRAL AREA

24. PROPER SITTING TECHNIQUE - Should Not Be Done Over Long Periods Of Time
HIPS SHOULD BE FLEXED
LEGS SHOULD NOT BE EXTENDED
BACK SHOULD NOT BE OVERLY ARCHED

25. LIFTING WITH PROPER TECHNIQUE
BACK KEPT ERECT
KNEES BENT
WEIGHT CLOSE TO BODY

26. STRENGTHENING EXERCISES
MANY BACK PROBLEMS ARE CAUSED BY WEAK MUSCLES ABOUT THE HIP AND ABDOMINALS
WEAK MUSCLES PREDISPOSE BACK TO HYPERLORDOSIS
INCORRECT SIT-UPS MAY CAUSE HYPERLORDOSIS - CAUSED BY SHORTENED ILIOPSOAS
STRETCHING - HAMSTRINGS - ILIOPSOAS - QUADRICEPS

27. LUMBAR SPINE EVALUATIONS
STANDING EVALUATION
FLEX FORWARD - PALPATING SPINOUS PROCESSES & TRANVERSE PROCESSES
SITTING ALIGNMENT
PATELLULAR REFLEX - LUMBAR 4 INVOLVEMENT
ACHILLES REFLEX - SACRAL 1 INVOLVEMENT

28. LYING ON BACK
TEST ABDOMINALS - RECTUS ABDOMINUS , ILIOPSOAS (HIP FLEXORS)
(STATIC W/ STABILIZED THIGHS - HIP FLEX AT 45 DEGREES
STRAIGHT LEG RAISE
PAIN WHEN TESTING UNAFFECTED SIDE - POSSIBLE HERNIATED DISK
PAIN WHEN TESTING AFFECTED SIDE - POSSIBLE SCIATIC NERVE STRETCHED

29. LYING ON BACK (CONTINUED)
BOWSTRING SIGN
TO TEST FOR SCIATIC NERVE - USE PRESSURE TO POPLITEAL (BACK OF KNEE)
GAINSLENS SIGN
TO TEST SACRO-ILIAC LESSIONS (SWITCHBLADE LEGS WHILE ON SIDE)

30. OTHER PROBLEMS OCCURING WITH THE SPINE
SOFT TISSUE TRAUMA - CONTUSIONS
NERVE INFLAMATION OR COMPRESSIONS - FROM DISK PROTRUSIONS
FRACTURES TO THE SPINOUS OR TRANSVERSE PROCESSES
SPONDYLOLYSIS (FRACTURE TO INTERARTICULAR PROCESS
SPONDYLOLISTHESIS (FORWARD SLIPPAGE OF THE VERTEBRA

31. OTHER PROBLEMS OCCURING WITH THE SPINE (CONTINUED)
GROIN STRAINS
HIP POINTE.RS
HIP DISLOCATIONS

32. REHABILITATION OF BACK AND HIP INJURY
ICE MESSAGE
MOVEMENT TO REGAIN FLEXIBILITY & RANGE
STRENGTHENING EXERCISES
SIT UPS & CRUNCHES (WORK OBLIQUES AS WELL)
PELVIC TILTS - (FLATTENING OF BACK AGAINST FLOOR)
HIP LIFTS - (FROM LYING ON BACK POSITION)
BACK EXTENTIONS - TO 90 DEGREES
PSOAS & HAMSTRING STRETCH - (KNEES TO CHEST)