This page can get rather technical, but it is an attempt to provide some of the terms used by all health professions to describe movements.  These definitions only begin to make sense when the orientation of the motion is understood.  It is the my intention to return to this page for updates and clarifications to improve clarity but also as input is received from the visitors to the page.  There are several sources for anatomical terminology, this one is based from Kendall and Kendall, Manual Muscle Testing.

Anterior describes a relative position towards the front of the body, your nose is anterior to your eye, your eye is anterior to your ear.

Distal is the opposite of proximal.  Distal describes a relative position on the extremities that is further from the insertion of the extremity into the torso;  the wrist is distal to the shoulder no matter the position of the arm.

Inferior (or Caudad which is Latin for tail) describes a relative position on the torso and head.  Inferior describes a position away from the head (towards the tail), it does not mean below.  So if one is standing, laying, or flexed at the waist in space the waist is inferior to chin.

Lateral describes a relative position away from the midline; when your arms are resting at your sides your hand is lateral to your navel.

Medial describes a relative position toward the midline, and is the opposite of lateral.  So, in the example above the navel is medial to the hand.

Posterior describes a relative position towards the back of the body, your ear is posterior to your jaw bone.

Proximal describes a relative position on the extremities that is closer to the insertion of the extremity into the torso;  the elbow is proximal to the hand no matter the position of the arm - at the side or reaching forward or bent at the elbow putting a pretzel into ones mouth.  The knee is always proximal to the foot.

Superior describes a relative position on the torso and head.  Superior describes a position toward the head, it does not mean above.  So if one is standing, laying, or flexed at the waist in out space the head is superior to that navel.


These are the common terms used to describe where something is on and in the body.  If it seems overly complicated think about the last time you tried to describe where an itch was on your back.  If you used the terms above to the scratcher, and the scratcher understood the terms, you can zero in on that itch in short order.  Add a few bony landmarks and that itch is scratched pronto.  The same holds true when health professional are describing areas on the body to each other when the subject is absent, when they cannot point to the area in front of them and say "there."
 
Planes

The three basic planes of reference are derived from the dimensions of space, and are at right angles to each other.   A sagittal plane is vertical and extends from front to back. It may also be called an anterior-posterior or front-back plane.  The midsagittal plane divides the body into right and left halves.

   
Axes

 Axes are lines, real or imaginary, about which movement takes place. Related to the planes of reference are three basic types of axes at right angles to each other.

 

 A sagittal axis lies in the sagittal plane and extends horizontally from front to back. The movements of abduction and adduction take place about this axis in a coronal plane.

 A coronal axis lies in the coronal plane and extends hortizontally from side to side. The movements of flexion and extension take place about this axis in a sagittal plane.

 A longitudinal axis is vertical extending in a top-bottom direction, and permits medial and lateral rotation movements.

 The exception to these general definitions occur with respect to movements of the scapula, clavicle, and thumb.

Definitons of Joint Movements

Joints are of three types: Fibrous of immovable, cartilaginous or slightly moveable, and synovial or freely moveable. The following definitions refer to snyovial joints.

Flexion and extension

Flexion and extension are movements in the sagittal plane. Flexion is movement in the anterior direction for joints of the head, neck trunk, upper extremity and hip. As in a nod of the head to mean "yes", bending the head forward is flexion, bending the head back is extension.  Flexion of the knee is a posterior direction which brings the foot toward the buttock. Extension is movement in a direction opposite flexion.

Abduction and adduction

Abduction and adduction are movements in the coronal plane. Abduction is movement away from and adduction is movement toward the midsagittal plane of the body for all parts of the extremities except the thumb, fingers, and toes. For the fingers, abduction and adduction are movements away from and toward the axial (center) line which extends through the third digit. For the toes the axial line extends through the second digit.

Lateral Flexion

Lateral flexion is a term used to denote lateral movements of the head, neck and trunk in a coronal plane. Bringing ones ear toward ones shoulder is lateral flexion of the head and neck.  Lateral flexion of the trunk is often used in gait to compensate for weak hip muscles.

Rotation

Rotation refers to movement about a longitudinal axis for most of the body.   In the extremities the anterior (front) surface of the extremity is used as a reference area. Rotation of the anterior surface toward the midsagittal (center) plane of the body is medial rotation, away from the midsagittal plane is lateral rotation.

Tilt

Tilt is a term used in describing certain movements of the pelvis. 

   

In a lateral pelvic tilt the pelvis is not level from side to side, but one side of the pelvis is higher that the other. In standing, a lateral tilt is associated with lateral flexion of the lumbar spine and adduction and abduction of the hip joints. For example, in a lateral tilt of the pelvis in which the right side is higher than the left, the lumbar spine is laterally flexed toward the right resulting in a curve convex to the left. The right hip joint is in adduction, and the left is in abduction.

Circumduction

When flexion, extension, abduction, and adduction are combined and in succession produce a circular movement of the distal end of a part, the movement that results is called circumduction.

Hip Joint
     
    Flexion and extension are movements about a coronal axis. Flexion is movement in an anterior direction. The movement may be one of moving the thigh toward the fixed trunk as when one is laying down on one's back and raising the leg up in the air; or the movement may be one of bringing the trunk towards the fixed thighs as in bending forward from standing position to touch the toes. Extension is movement in a posterior direction. The movement may be one of bringing the thigh posteriorly as in leg-raising backward; or one of bringing the trunk posteriorly as in returning from a standing forward-bent position.
   
    Abduction and adduction are movements about a sagittal axis. Abduction is movement away from the midsagittal plane in a lateral direction. In a supine position the movement may be one of moving the thight laterally on a fixed trunk or moving the trunk so that the pelvis tilts laterally (downward) toward the flexed thigh. Adduction is movement of the thigh toward the midsagittal plane in a medial direction. In s supine position, the movement may be one of moving the thigh medially on a fixed trunk so that the pelvis tilts laterally (upward) away from a fixed thigh. (For abduction and adduction of the hip joints accompanying lateral pelvic tilt).
    The range of abduction from zero is apporximately 45 degrees, of adduction, 10 degrees, making the total range about 55 degrees.
    Lateral and medial rotation are movements about a longitudinal axis. With the anterior surface of the thigh and the midsagittal plane as referneces, medial rotation refers to turning the thigh inward and lateral rotation to turning the thigh outward. Rotation may also result from movement of the trunk ono the femur. For example, when standing on the right leg, counter-clockwise rotation of the pelvis will result in lateral rotation of the hip joint.

Knee joint
    
    Flexion and extension are movements about a coronal axis. Flexion is movement in a posterior direction, approximating the posterior surfaces of the leg and thigh. Extension is movement in an anterior direction to a position of straight alignment of the thigh and leg. From the position of zero extension the range of flexion is approximately 140 degrees. The hip joint should be flexed when measuring full knee joint flexion to avoid restriction of motion by the Rectus femoris; and should not be fully flexed when measuring knee joint extension to avoid restriction by the Hamsting muscles.
    Hyperextension is an abnormal or unnatural movement beyond the zero position of extension. For the sake of stability in standing, the knee normally is expected to be in a position of a very few degrees extension beyond zero. If extended beyond these few degrees, the knee is said to be hyperextended.
    Lateral and medial rotation are movements about a longitudinal axis. Rotation of the anterior surface of the leg toward the midsagittal plane is lateral rotation.
    The extended knee is esentially locked, preventing any rotation . Rotation occurs with flexion, combining movement between the tibia and the menisci as well as movement between the tibia and the femur.
    With the thigh fixed, the rotation that accompanies flexion is described as medial rotation of the tibia on the femur. With the leg fixed, the movement is one lateral rotation of the femur on the tibia.
    Moving in the direction of the extension the reverse occurs; with the thigh fixed, lateral rotation of the tibia on the femur; with the leg fixed, medial rotation of the femur on the tibia.

The ankle joint is formed by the articulation of the tibia and fibula with the talus.The axis about which motion takes place extends obliquely from the postero-anteromedial position of the tibial malleolus.
Flexion and extension are the two movements that occur about the oblique axis. Flexion is movement in which the foot moves in a caudal and posterior direction. Extension is movement in which the foot moves in an anterior and cranial direction.
Confusion has arisen about the terminology of these two ankle joint movements. This is due in part to the fact that the developmental pattern of the upper extremity differs from that of the lower extremity. At an early stage, the limbs of the embryo are directed ventrally, the flexor surfaces medially, and the great toes and thumbs cranially. With further development the limbs rotate 90 degrees at their girdle articulation so that the thumbs turn laterally and the flexor surfaces of the upper extremities vetrally, while the great toes turn medially and the flexor surfaces of the lower extremities dorsally. As a result of this 90 degree rotation of the limbs in opposite directions, movement which apporximates the hand and the anterior surface of the forearm is termed flexion since it is performed by flexor muscles, and movements which approximates the foot and anterior surface of the leg is termed extension since it is performed by extensor muscles.
Another apparent discrepancy occurs because decreasing an angle is frequently associated with flexion while increasing it is associated with extension. Bringing the foot upward to "bend the ankle" seems to connote flexion, while pointing theh foot
downward to "straighten the ankle" connotes extension. To avoid confusion, there has been rather widespread acceptance of the terms dorsiflexion for extension and plantar flexion for flexion. This text will adhere to the use of these generally accepted terms. With the knee flexed, the ankle joint can be dorsiflexed about 20 degrees. With the knee extended, the Gastrocnemius may limit the range of motion about 15 degrees. The range of motion in plantar flexion is approximately 45 degrees.

Deformities of the foot and ankle
    In the following list, foot deformities are defined in terms of the positions of the involved joints. In severe deformities the position of the joint is beyond the normal range of joing motion.
Talipes valgus: Foot everted and accompanied by flattening of the longitudinal arch.
Talipes varus: Foot inverted and accompanied by and increase in the height of the longitudinal arch.
Talipes equinus: Ankle joint plantar flexed.
Talipes equinovalgus: Ankle joint plantar flexed and foot everted.
Talipes equinovarus: Ankle joint plantar flexed and foot inverted. (Club foot).
Talipes calcaneus: Ankle joint dorsiflexed.
Talipes calcanerovalgus: Ankle joint dorsiflexed and foot everted.
Talipes calcaneovarus: Ankle joint dorsiflexed and foot inverted.
Talipes cavus: Ankle joint dorsiflexed, forefoot plantar flexed, resulting in a high longitudinal arch. With the change in position of the calcaneus, the posterior prominence of the heel tends to be obliterated, and weight-bearing on the calcaneus shifts posteriorly.