1. To quickly search this FAQ page use Ctrl-F (PC) or Cmd-F (Mac)  and then type in the keywords in the Find box.
2.  If you use "Search this site", it will search all pages on this website which may not be what you want.

Anatomical References

Medial - Closer to the midline of a person
Lateral - Away from the midline of a person
For example the medial aspect of the knee is the part of the knee that is closest to the other knee.

Proximal - Closer to the point of reference such as closer to the referenced surgeon or patient.
Distal - Away from the point of reference such as closer to the referenced surgeon or patient.

Adduction - the rotation of a limb toward the midline or axis of the body
Abduction - the rotation of a limb away from the midline or axis of the body

Body Planes
Saggital, Coronal and Transverse


Tendons are composed mostly of closely packed parallel arrays of collagen fibers connect muscle to bone.  Its structure is capable of resisting great tension.  When the muscle contracts, it creates tension in the tendon and cause the bone to rotate around the nearby joint.


Ligaments have similar structure to tendons except that it connects one bone to another bone and usually span across a joint.

Food and Drug Administration (FDA)

The Federal government agency that has regulatory authority over the manufacture, distribution, and labeling of drugs, medical devices, and foods.


Institutional Review Board (IRB)

A committee designated by an institution, such as a hospital, to review and approve research projects; e.g. clinical studies in that institution.

Investigational Device Exemption (IDE)

A FDA regulatory status which permits the human use of an unapproved medical device for the purpose of collecting clinical data under strictly controlled conditions.

These devices fall somewhere between research and ordinary clinical practice. They do not undergo the same stringent requirements that investigational devices do in order to commercially market them, yet they may be recognized as the “approved” standard, and in some cases, preferred medical device.

 Premarket Notification [510(k)]

A regulatory method for gaining clearance from the FDA to market a device. The FDA is petitioned by a company to determine if a particular medical device is “substantially equivalent” to a device which was commercially available prior to May, 28, 1976. This method usually applies to Class I or II medical devices.

 Premarket Approval (PMA) 

A regulatory method for gaining a marketing clearance from the FDA for a Class III medical device. A company submits information to the FDA that documents the safety and effectiveness of the device.


Anatomical References

Proximal  Nearest the center of the body.

Anterior – The front portion of the body. It is often used to indicate the position of one structure relative to another.

Posterior – Located behind a structure, such as relating to the back side of the human body.

 Distal – Situated away from the center of the body.


A simple sac or cavity with smooth walls and containing a clear, slightly sticky fluid interposed between two moving surfaces of the body to reduce friction. Subcutaneous bursae are found where the skin stretches around the greater curvature of a joint, as in the elbow or knee, and considerable chafing may occur; they may be single or multiple sacs. These bursae may enlarge as a result of continuous excessive irritation, as in housemaid's knee or miner's elbow.

Synovial bursae are small closed sacs of fibrous tissue continuous with the joint cavity of a diarthrosis. They are lined with a complex membrane that secretes a clear lubricating fluid, serving to reduce friction between the opposing surfaces of the articulation.

Bursae may exist in the form of elongated sheaths surrounding tendons or ligaments, where these moving bands are in contact with another structure, such as a bone, muscle, or another tendon or ligament. Tendon sheaths are especially common where tendons bend around the ends of two bones at an articulation.