Frontal Plane about the anterioposterior axis
Though flexion and extension can occur in a variety of planes depending on the body's position, if you have a body in anatomical position, then all flexion and extension occurs on the sagittal plane.
During a sit-up, the primary joint movements that occur are hip flexion as the hips bend, lumbar spine flexion as the back rounds forward, and thoracic spine flexion as the upper body moves towards the knees. The shoulder movement might also involve slight flexion as the arms reach forward towards the knees.
Trunk flexion occurs in the sagittal plane of body motion. This movement involves bending the torso forward, bringing the chest toward the thighs. It primarily involves the muscles of the back and abdomen.
Simply stated, flexion is when the angle around a joint is decreased from it's normal position (from the anatomical position) in the SAGITTAL plane. The sagittal plane is an imaginary line that splits your body into left and right pieces. All flexion moves in this plane. Ex. Flexion of the bicep requires you to pull your forearm (decrease the angle) toward your head. That motion running along the side of your body is also in the sagittal plane
Shoulder circumduction is a multiplanar motion that occurs in the sagittal, frontal, and transverse planes. It involves a combination of flexion, extension, abduction, adduction, and internal and external rotation at the shoulder joint.
Though flexion and extension can occur in a variety of planes depending on the body's position, if you have a body in anatomical position, then all flexion and extension occurs on the sagittal plane.
Transverse plane
balance
balance
Vertebral Foraminal Entrapment on Hip Flexion and Knee Extension
During a sit-up, the primary joint movements that occur are hip flexion as the hips bend, lumbar spine flexion as the back rounds forward, and thoracic spine flexion as the upper body moves towards the knees. The shoulder movement might also involve slight flexion as the arms reach forward towards the knees.
Hip adduction occurs in the frontal plane of motion. This movement involves bringing the leg toward the midline of the body.
hip flexion and hip extention
Trunk flexion occurs in the sagittal plane of body motion. This movement involves bending the torso forward, bringing the chest toward the thighs. It primarily involves the muscles of the back and abdomen.
The prim mover for hip flexion is the Rectus femoris. This is a quadricep muscle that crosses the hip joint.
rectus femoris
Pectineus