Excessive Forward Lean
Overactive
(Gastrocnemius, Hip Flexors)
Gastrocnemius - accelerates plantar flexion and externally rotates tibia.
Rectus Femoris (Hip Flexors) - accelerates knee extension and hip flexion.
Psoas (Hip Flexors) - accelerates hip flexion and external rotation, extends and rotates lumbar spine.
Underactive
(Gluteus Maximus, Erector Spinae)
Gluteus Maximus - accelerates hip extension and external rotation.
Iliocostalis: Lumborum Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Iliocostalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Longissimus: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Spinalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Low Back Arches
Overactive
(Latissimus Dorsi, Erector Spinae)
Latissimus Dorsi - shoulder extension, adduction, and internal rotation.
Iliocostalis: Lumborum Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Iliocostalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Longissimus: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Spinalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Underactive
(Hamstrings, Core)
Biceps Femoris-Long Head (Hamstrings) - accelerates knee flexion, hip extension, and tibial external rotation.
Biceps Femoris-Short Head (Hamstrings) - accelerates knee flexion and tibial external rotation.
Semimembranosus (Hamstrings) - accelerates knee flexion, hip extension, and tibial internal rotation.
Semitendinosus (Hamstrings) - accelerates knee flexion, hip extension, and tibial internal rotation.
Transverse Abdominis (Core) - increases intra-abdominal pressure. Supports the abdominal viscera.
Multifidus (Core) - spinal extension and contralateral rotation.
Transversospinalis: Thoracis Division (Core) - produces spinal extension and lateral flexion; extension and contralateral rotation of the head.
Internal Oblique (Core) - spinal flexion (bilateral), lateral flexion, and ipsilateral rotation.
Diaphragm (Core) - pulls the central tendon inferiorly, increasing the volume in the thoracic cavity.
Low Back Rounds
Overactive
(Hamstrings, Adductors)
Biceps Femoris-Long Head (Hamstrings) - accelerates knee flexion, hip extension, and tibial external rotation.
Biceps Femoris-Short Head (Hamstrings) - accelerates knee flexion and tibial external rotation.
Semimembranosus (Hamstrings) - accelerates knee flexion, hip extension, and tibial internal rotation.
Semitendinosus (Hamstrings) - accelerates knee flexion, hip extension, and tibial internal rotation.
Adductor Longus (Adductors) - accelerates hip adduction, flexion, and internal rotation.
Adductor Magnus-Anterior Fibers (Adductors) - accelerates hip adduction, flexion, and internal rotation.
Adductor Magnus, Posterior Fibers (Adductors) - accelerates hip adduction, extension, and external rotation.
Adductor Brevis (Adductors) - accelerates hip adduction, flexion, and internal rotation.
Gracilis (Adductors) - accelerates hip adduction, flexion, and internal rotation.
Pectineus (Adductors) - accelerates hip adduction, flexion, and internal rotation.
Underactive
(Gluteus Maximus, Erector Spinae)
Gluteus Maximus - accelerates hip extension and external rotation.
Iliocostalis: Lumborum Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Iliocostalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Longissimus: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Spinalis: Thoracis Division (Erector Spinae) - spinal extension, rotation, and lateral flexion.
Arms Fall Forward / Elbows Flex
Overactive
(Lats, Pecs)
Latissimus Dorsi - shoulder extension, adduction, and internal rotation.
Pectoralis Major (Pecs) - shoulder flexion (clavicular fibers), horizontal adduction, and internal rotation.
Pectoralis Minor (Pecs) - protracts the scapula.
Underactive
(Traps, Rhomboids)
Middle Trapezius (Traps) - scapular retraction.
Lower Trapezius (Traps) - scapular depression.
Rhomboids - produces scapular retraction and downward rotation.
