Body Mechanics and Posture Flashcards
Rectus Abdominis
Origin: Pubic Symphysis
Insertion: costal cartilages of ribs 5,6,7 and xiphoid process
Tightness of lower abdominals causes pelvis to do: Posterior Pelvic Tilt (PPT)
Weakness of the lower abdominals causes pelvis to do: Anterior Pelvic Tilt (APT)
If Unilateral is tight?: Leg Length Discrepancy (LLD)
Internal Oblique
Origin: Anterior Iliac Crest
Insertion Ribs 9-12
Action: rotation to the same side
External Oblique
Origin: Ribs 5-12
Insertion: Linea alba, pubis, anterior iliac crest
Action: rotation to the opposite side
Quadriceps Femoris Group
Origin: anterior inferior iliac spine
Insertion: Tibial Tuberosity
Action: Hip Flexion
Tightness: APT
Weakness: PPT
Unilateral Tight: LLD
Hamstring
Origin: Ischial Tuberosity
Insertion: Tibia
Action: Hip Extension
Tightness: PPT
Weakness: APT
Unilateral: LLD
Back Extensors
Origin: Posterior Pelvis
Insertion: Spine and Ribs
Action: Thoracic and Lumbar Extension
Tightness: PPT
Weakness: APT
Unilateral: LLD
Quadratus Lumborum
Origin: Iliac Crest
Insertion: Ribs
Action: Lateral Flexion - Pelvis: Hip Raise
Left/Right Tightness: pull pelvis left/right upward tilt
Left/Right Weakness: left/right downward tilt - pelvis shifts
Curves of the Spine
Kyphosis: Thoracic Spine
Lordosis: Cervical and Lumbar Spine
Rationale for Lumbar Lordosis Posture
- Reduces mechanical stress to the lumbar ligaments and intervertebral disc (IVD)
- Compression forces the IVD are directed anteriorly rather than posteriorly
- Lumbar spine stability is increased due to the approximation of the vertebral facets
- Function of the lumbopelvic force couple is maximized
- Muscles are positioned to function more effectively at the anterior and posterior lower trunk and hip and thigh extensor muscles
Annulus Fibrosus
Tough circular exterior of the IVD that surrounds the soft inner core, the nucleus pulposus. This outer portion is composed of a ring of ligament fibers that encases the inner core of the disc and securely connects the spinal vertebrae and below the disc
Nucleus Pulposus
Jelly-like substance in the middle of the spinal disc
Intervertebral Disc
Helps to maintain a healthy back but can put pressure on spinal cord/nerves
Function to distribute hydraulic pressure in all directions within each disc under compressive loads
- Left side bending causes the disc to displace: right side
- Right side bending causes the disc to displace: left side
- Trunk Extension (increase in lordosis) causes the disc to displace: anterior (front)
- Trunk Flexion (reverse or decrease lordosis) causes the disc to displace: posterior (back)
- Right rotation causes the disc to displace: Posterior Lateral (Right)
- Left Rotation causes the disc to displace: Posterior Lateral (Right)
- Which of the above motions would be the worst? Trunk Flexion with Rotation
Maintenance of a Healthy Back
- Appropriate Strength
- Appropriate Flexibility
- Proper Nutrition-Hydration
- Rest
- Good Posture
- Use of proper body mechanics
Causes of Stress to the spine is multifactorial
- Faulty posture or positioning
- Overall Stress
- Inability to relax or staying in a prolonged posture
- Poor Flexibility
- Improper lift, push, pull, reach, or carry
- Physical Condition
- Sustained trunk flexion and/or rotation
- Maneuvering too large of an object
- Repetitive, sustained micro-trauma to structures
- Episode of trauma that culminates in one specific or final event due too many of the above causing this “final straw”
Structures that can be injured in the back
- Nerves
- Discs
- Spinal Cord
- Ligaments
- Tendons
- Muscles
- Bony Defect
Body Mechanics
Use of one’s own body to produce motion that is safe, energy conserving, efficient, and controlled
Valsalva Phenomenon or Maneuver
- Occurs when an individual holds their breath and air is trapped in the thorax increasing intrathoracic pressure
- Could cause severe damage such as a stroke - CVA (cerebral vascular accident)
How does gravity affect body mechanics?
Increase amount of force needed to exert thus it is better to push or pull over lifting an object
How does friction affect body mechanics?
Creates increase needed force thus adding wheels would decrease the force required
Where is the location where the majority of the mass of the bod or object is concentrated?
Center of Gravity (COG) or Center of Mass (COM)
Adult human location of COG or COM
Sacral Level 2 (SL2)
Is it harder to maintain one’s balance and perform good body mechanics when one is standing or squatting?
Standing - it is harder when legs are straight
EX: roller skating, knees bent
How can placing the objects COM closest to your COM improve body mechanics?
EX: raising bed higher or sitting on a stool to match height of patient. By using my COM it helps me move another COM
Define BOS
Base of Support: area an object rests and provides support for the object
Define AP Stance
Anterior-Posterior Stance: most stable, front to back lateral feet
Define Medial-Lateral Stance
Less stable (feet shoulder width apart and even)
What is a device that can increase one’s BOS?
Walker, Wheelchair, Crutches
Define VGL
Vertical Gravity Line: imaginary line that passes through an objects COG
What happens if VGL is not within BOS?
LOB (loss of balance) - shifting weight
Why should you position yourself as close to the object as possible?
- Short lever arm and decreases torque on the anatomical structures
- Allows for one COM to move another COM
Define LE
Lower Extremity
Why should you avoid simultaneous trunk flexion and rotation?
Pushes the disc towards the spinal cord and can cause herniated disc
What should you do prior to lifting?
Stretch, Walk, Motion
Steps for lifting
- Follow body mechanics
- Maintain neutral spine by isometric abdominal contraction in slight PPT position
- Exhale on Exertion
- Do not lift and twist or lift with jerky motions
- Avoid repetitive and sustained lifting
- Do orthotic devices such as lumbar support help?
- only when the lift is needed, loosen throughout the day - weakens muscles
Steps for pushing and pulling
- Flex knees and face object squarely
- Use arms and legs to push/pull
- Use proper body mechanics
- Apply force/to surface that the object is being moved
- Minimize friction when possible
- Clear the path
Steps for Reaching
- Move the object close to your COM
- Raise the COM if the object is overhead - get a step stool
Steps for carrying objects
- Balance the load
- Centralize the weight of the object close to your COM
- EX: Backpack - even straps, put backpack on table then put on each shoulder
What does Plumb Line do?
Assess Posture
Example of Plumb Line Demonstration
- Stand with the string in front of the lateral malleolus
- Slightly anterior to the lateral malleolus
