What is postural stability?
Maintaining center of mass within the limits of the base of support
Relies on passive (bones/ligaments) and active (muscles/neuromuscular control) components.
What are the two types of postural stability?
- Static; maintains steadiness on a fixed, unmoving surface
- Dynamic; integration of sensorimotor information to establish equilibrium between destabilizing and stabilizing forces
What sensory systems contribute to postural control?
- Visual
- Vestibular
- Somatosensory or proprioceptive
- Motor systems
What is the role of the pelvis in postural stability?
Strong ring structure and joints offering good form closure (passive)
Provides a stable base for the trunk.
How does the thoracic cage assist in stability?
Assists in stabilizing against excessive movement
What is the role of the lumbar spine in postural stability?
Large vertebral bodies, relies on muscles and fascia for dynamic support
What contributes to the stability of the cervical spine?
Stability via muscles and connective tissues
What is postural sway?
Natural continuous movement to maintain balance during upright posture
Which muscles alternate to control postural sway during quiet standing?
- Paraspinal muscles
- Abdominal muscles
What is the primary function of the global muscles in lumbar spine stability?
Achieve active or dynamic stability through muscle contraction
What are the local muscles involved in lumbar spine stability?
- Transverse Abdominis (TA)
- Multifidus
- Diaphragm
- Pelvic diaphragm
What is the lumbopelvic rhythm?
Pelvis and lumbar spine move in the same direction
What occurs during trunk flexion?
Lumbar vertebrae flex -> anterior pelvic tilt -> hip flexion
Describe the differences between standing and sitting posture.
- Standing: Lumbar spine lordotic, pelvis neutral/ant tilt, hip joint ext
- Sitting: Lumbar spine flexion, pelvis tilts posteriorly, hip joint flexion
What activates to initiate trunk flexion in the sit-to-stand movement?
Abdominal muscles
What muscle actions are involved in the downward acceleration phase of sit-to-stand?
- Eccentric of trunk extensors
- Eccentric of quadriceps
How does the sit-to-stand movement differ for the elderly?
- Quicker movements via momentum
- Exaggerated trunk flex prior to lift off
- Delayed trunk extension
- Dominant vertical rise
What is the myofascial connection of the thoracolumbar fascia (TLF)?
- Retinaculum for back muscles
- Attachment for anterior abdominal muscles
- Provides attachment for limb muscles
What stabilizing tension is provided by the TLF?
Tension via surrounding muscles, mainly Transverse Abdominis (TA)
What is the role of the abdominal aponeurosis?
Supports the anterior abdominal wall and stabilizes the lumbar vertebral column
What defines core stability?
Ability to achieve and sustain control of the trunk region at rest during precise movement
What is the role of intra-abdominal pressure in core stability?
Increases via core muscle activation when increased core stability is required
List the muscles involved in dynamic stabilization of the vertebral column.
- Abdominal muscles anteriorly
- Paraspinal and gluteals posteriorly
- Diaphragm superiorly
- Pelvic floor inferiorly
- Hip lateral rotators
- Extensors laterally
True or False: Better core stability and dynamic postural control are important for accuracy in sports.
True
