The relationship of the pelvis to the reference line is largely determined by the relationship of the pelvis to hip joints. Because the reference line from the side view represents the plane that passes slightly posteriorly At the axes of the hip joints, the pelvis will cross at the acetabulum. However, these benchmarks are it is not enough to establish the position of the pelvis, because the pelvis can lean forward or backward on the trees through the hip joints. Therefore, it is necessary to define the neutral position of the pelvis in the standard posture. The neutral position used as standard in this text is that in which the anterior-superior iliac spines are in the same horizontal plane and in which the anterior-superior iliac spines and the pubic symphysis are in the same vertical plane. From the point of view of the action of the muscles attached to the anterior iliac spines and of the pubic symphysis, the opposing muscle groups have the same mechanical advantage in a straight line of traction. The rectus abdominis, with its insertion into the pubis, extends upward to the stem, and the rectus femoris, the sartorius and the tensor fascia lata, with their insertions into the anterior iliac spines, extend towards the low to the thigh. Due to the structural variations of the pelvis, it is impractical to describe a neutral position based on a specific anterior point and a specific posterior point that lie in the same horizontal plane. Superior anterior iliac However, the dorsal spines and the posterior superior iliac spines are approximately in the same plane. In the neutral position of the pelvis, there is a normal front curve in the lower back. In the anterior inclination of the pelvis there is a lordosis. In the posterior tilt of the pelvis, there is a flat back. Without detracting from the correct positions of the foot that establish the support base, it can be said that the position of the pelvis is the key to good or poor postural alignment. Muscles that maintain good pelvic alignment, both anteroposterior and lateral, are of the utmost importance in maintaining good overall alignment. The imbalance between the opposing muscles in the standing position changes the alignment of the pelvis and negatively affects the posture of the parts of the body both above and below.


The standard reference line of the side view through the lower ends passes slightly behind the center. of the hip joint and slightly anterior to the axis of the knee joint and represents a stable position of these joints.

If the center of the supporting joint coincides with the line of gravity, the joint has the same tendency to flex and extend. However, this centered joint position is not stable to bear the weight. The slightest force exerted in any direction will cause it to move off-center unless stabilized by constant muscular effort. If the body has to exert muscular effort to maintain a stable position, energy is unnecessarily wasted. If the hip and knee joint were to move freely in both extension and flexion, there would be no stability and constant effort would be required to resist movement in both directions. A stable off-center position for a joint depends on limiting movement of the joint in one direction. For the hip and knee, the extension is limited. Ligamentous structures, strong muscles and tendons are the restraining forces that prevent hyperextension. Stability in standing position is achieved by this normal limitation of joint movement. Exercises or manipulations that tend to hyperextend the knee or hip joint or that over-stretch muscles, such as the hamstrings, should be carefully examined. The normal holding influence of the ligaments and muscles helps to maintain good postural alignment with minimal muscular effort. When muscles and ligaments do not offer adequate support, the joints exceed their normal range and posture becomes defective with respect to the knee and hip hyperextension positions.


The standard reference line passes slightly in front of the lateral malleolus and approximately through the vertex of the arch, indicated laterally by the calcaneocuboid joint. Normally, the shoulders flex the ankle with the knee. extended is about 10 °. This means standing barefoot with your feet in a slightly outward position as well With straight knees, the lower leg cannot swing forward on the foot more than 10 °. Forward deviation of the body (ankle dorsiflexion) is controlled by the restrictive tension of strong back muscles and ligaments. However, this support element is materially altered with variations in heel height that position the ankle in varying degrees of plantar flexion, and is significantly impaired if the knees are flexed.


In the standard position, the foot position is where the heels are about 3 inches apart and the front of the feet are separated so that the angle of the toe is approximately 8 ° to 10 ° from midline on each side, for a total of 20 ° or less. This foot position refers only to the static and barefoot position. Both the elevation of the heels and the movement affect the position of the feet. In establishing a standard foot position, and determining where, if anything, the toe out should occur, it is necessary to consider the foot in relation to the rest of the lower limb. Toe position cannot occur in the knee, because there is no rotation in extension.

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