There are three planes of motion that scientists use to describe movement of the joints of the body. The three planes are the saggital plane, horizontal or transverse plane and frontal plane. The frontal plane can be visualized by standing with your back to a wall. Movements that can be executed with the arms, legs, and back touching the wall at all times are frontal plane movements.
Frontal Plane Movements
The joint actions that occur in the frontal plane are abduction, or movement away from the midline of the body; adduction, or movement toward the midline of the body; lateral spinal flexion, or bending to the side; and reduction of the spine, or movement from lateral flexion back to neutral. Some joints are structured to allow for movement in one, two or all three planes. Those that move in the frontal plane are the shoulder, hip and intervertebral joints.
Shoulder Movements in the Frontal Plane
Abduction of the shoulder occurs when you lift your arms from your sides until your hands touch over your head. Adduction is the same movement in the opposite direction. Exercises that challenge the muscles responsible for abduction of the shoulder are lateral raise, upright row and overhead or military press. The shoulder adductors are responsible for shoulder movement during the lat pulldown and straight arm side pulldown. Jumping jacks are a dynamic exercise in which both abduction and adduction of the shoulder occur.
Hip Movements in the Frontal Plane
The hip joint is the same structure as the shoulder joint, so the movement capabilities of the shoulder and hip are identical. Abduction of the hip occurs when the leg is lifted to the side, and adduction occurs when the legs come back together. Side-lying leg lifts work the hip abductors when the top leg is lifted and work the adductors when the bottom leg is lifted. Seated hip abductor and adductor exercise machines are also commonly found in gyms. As with the shoulder, jumping jacks work the hip abductors and adductors dynamically.
Spinal Movements in the Frontal Plane
Although the structure of the intervertebral joints is different from the hip and shoulder, the movements possible at the joints are the same. At the intervertebral joints, lateral movements are called right or left lateral flexion, depending on the direction of the side bend. Movement back to neutral standing is called reduction. Exercises in which these movement occur are side bends and side planks. During dynamic motion, lateral spinal flexion often occurs in concert with other spinal motions.