Muscular Units for Transfer of Force & Postural Distortions

Flashcards covering muscular units for force transfer, their components, and common postural distortions with their definitions as described in the lecture notes.

Musculoskeletal inefficiencies

Problems in joint segments that impair force transfer during movement and exercise.

Kinetic chain

The linked body segments employed for a specific action, across which forces are transferred.

Trunk efficiency

Critical for effective energy transfer from lower to upper and upper to lower body segments.

Inner unit

A collective group of local spinal and pelvic stabilizers that support the spine/pelvis.

Outer units (myofascial sling systems)

Global stabilizers that work reactively to control body segments and provide functional force closure.

Inner unit muscles

Includes transverse abdominis, diaphragm, posterior internal oblique, pelvic floor, and multifidus.

Outer units function

Global systems that stabilize the spine/pelvis during movements involving the extremities, working with the inner unit to transfer force.

Transverse abdominis (TVA)

Helps maintain proper intra-abdominal pressure and enhances the rigidity of the thoracolumbar fascia to brace the lumbo-pelvic region.

Multifidus

Contracts with the TVA to prevent undesirable changes in spinal segment positioning, creating 'hoop tension'.

Diaphragm

Serves as both a respiratory muscle and a local stabilizer via top-down support, capable of both simultaneously.

Pelvic floor

Stabilizes the front and back by acting on the pelvis, potentially initiating and capturing force within the inner unit.

Posterior oblique sling system

Includes the latissimus dorsi, gluteus maximus, and thoracolumbar fascia, forming a 'force transfer bridge' between the lumbar spine and pelvic girdle.

Anterior oblique sling system

Opposes the posterior oblique system via the combined function of the obliques, adductors, and abdominal fascia, creating anterior sling cross-stabilization.

Deep longitudinal sling system

Includes the erector spinae, thoracolumbar fascia, multifidus, and sacrotuberous ligament, connecting multiple joint segments for sprinting mechanics.

Lateral sling system

Includes the hip abductors, quadratus lumborum, and thigh adductors, providing frontal plane stability and aiding bipedal and climbing motions.

Postural or muscular imbalances

Impaired joint function and coordination between the inner and outer unit, leading to an increased risk for injury.

Reciprocal inhibition

Neuromuscular regulation of agonist-antagonist contraction patterns to reduce resistance during opposing joint actions, allowing fluid movement.

Forward head posture and/or rounded shoulders

Common postural distortions arising from muscular imbalances or chronically repeated actions/postures.

Winged scapulae

A lifted and outwardly-rotated scapular position that appears to protrude posteriorly away from the ribcage, causing shoulder dysfunction.

Upper cross syndrome

An upper body postural distortion with a forward head, raised/rounded shoulders, and an exaggerated thoracic curvature.

Kyphosis

Excessive convex curvature of the thoracic spine, presenting as a bowed or rounded back.

Lordosis

Excessive concavity or inward curvature of the lumbar spine, often part of lower cross syndrome.

Lower cross syndrome

A lower body distortion characterized by an undesirable anterior tilt of the pelvis with lordosis due to severe muscular imbalance in the lumbo-pelvic region.

Plumb line

A tool used to observe static variations in anatomical positions caused by postural distortions.

Muscle overactivity

A state where postural muscles tend to become immobile, and phasic muscles tend to weaken.

Upper body/extremity distortions

Clinically diagnosed musculoskeletal problems including forward chin, kyphotic exaggeration, upper cross syndrome, and Dowager’s hump.

Lumbo-pelvic-hip distortions

Clinically diagnosed musculoskeletal problems including lower cross syndrome and fixed pelvic tilting.

Lower/distal-extremity distortions

Clinically diagnosed musculoskeletal problems including knee rotation and ankle pronation/supination issues.

Fixed lateral pelvic tilting

A hip elevation on one side of the pelvis while the opposing side is depressed, creating problems with locomotion and stability.

Tibial-femoral dysfunction

Distortions seen at the knee and ankle joints, such as ankle over-pronation/supination, varus knees, and valgus knees.