Motion,the process of movement, is described using specificanatomical terms.Motion includes movement oforgans,joints,limbs,and specific sections of the body. The terminology used describes this motion according to its direction relative to theanatomical positionof the body parts involved.Anatomistsand others use a unified set of terms to describe most of the movements, although other, more specialized terms are necessary for describing unique movements such as those of the hands, feet, and eyes.
In general, motion is classified according to theanatomical planeit occurs in.Flexionandextensionare examples ofangularmotions, in which two axes of a joint are brought closer together or moved further apart.Rotationalmotion may occur at other joints, for example theshoulder,and are described asinternalorexternal.Other terms, such aselevationanddepression,describe movement above or below the horizontal plane. Many anatomical terms derive fromLatinterms with the same meaning.
Classification
editMotions are classified after theanatomical planesthey occur in,[1]although movement is more often than not a combination of different motions occurring simultaneously in several planes.[2]Motions can be split into categories relating to the nature of the joints involved:
- Glidingmotions occur between flat surfaces, such as in theintervertebral discsor between thecarpal bonesof thewrist,and themetacarpal bonesof thehand.[1]
- Angularmotions occur oversynovial jointsand causes them to either increase or decrease angles between bones.[1]
- Rotationalmotions move a structure in arotationalmotion along a longitudinal axis, such as turning the head to look to either side.[3]
Apart from this motions can also be divided into:
- Linearmotions (ortranslatorymotions), which move in a line between two points.Rectilinearmotion is motion in a straight line between two points, whereascurvilinearmotion is motion following a curved path.[2]
- Angularmotions (orrotarymotions) occur when an object is around another object increasing or decreasing the angle. The different parts of the object do not move the same distance. Examples include a movement of the knee, where the lower leg changes angle compared to the femur, or movements of the ankle.[2]
The study of movement in the human body is known askinesiology.[4]A categoric list of movements and themusclesinvolved can be found atlist of movements of the human body.
Abnormal motion
edit
The prefixhyper-is sometimes added to describe movement beyond the normal limits, such as inhypermobility,hyperflexionorhyperextension.Therange of motiondescribes the total range of motion that a joint is able to do.[5]For example, if a part of the body such as a joint is overstretched or "bent backwards" because of exaggerated extension motion, then it can be described ashyperextended.Hyperextension increases the stress on theligamentsof a joint, and is not always because of a voluntary movement. It may be a result of accidents, falls, or other causes of trauma. It may also be used in surgery, such as in temporarily dislocating joints for surgical procedures.[6]Or it may be used as apain compliancemethod to force a person to take a certain action, such as allowing a police officer to take him into custody.
General motion
editThese are general terms that can be used to describe most movements the body makes. Most terms have a clear opposite, and so are treated in pairs.[7]
Flexion and extension
edit
Flexion and extensionare movements that affect the angle between two parts of the body. These terms come from theLatinwords with the same meaning.[a]
Flexionis a bending movement thatdecreasesthe angle between a segment and its proximal segment.[9]For example, bending theelbow,or clenching a hand into a fist, are examples of flexion. When a person is sitting down, the knees are flexed. When a joint can move forward and backward, such as the neck and trunk, flexion is movement in the anterior direction.[10]When the chin is against the chest, the neck is flexed, and the trunk is flexed when a person leans forward.[10]Flexion of the shoulder or hip is movement of the arm or leg forward.[11]
Extensionis the opposite of flexion, a straightening movement thatincreasesthe angle between body parts.[12]For example, when standing up, the knees are extended. When a joint can move forward and backward, such as the neck and trunk, extension is movement in the posterior direction.[10]Extension of the hip or shoulder moves the arm or leg backward.[11]Even for other upper extremity joints – elbow and wrist, backward movement results in extension. The knee, ankle, and wrist are exceptions, where the distal end has to move in the anterior direction for it to be called extension.[13][page needed]
For thetoes,flexion is curling them downward whereas extension is uncurling them or raising them.[14]
Abduction and adduction
edit
Abduction is the motion of a structure away from the midline while adduction is motion towards the center of the body.[15]The center of the body is defined as themidsagittalorlongitudinalplane.[3]These terms come fromLatinwords with similar meanings,ab-being the Latin prefix indicating'away',ad-indicating'toward',andduceremeaning'to draw or pull'.[b]
Abductionis a motion that pulls a structure or partaway fromthe midline of the body, carried out by one or moreabductormuscles. In the case of fingers and toes, it is spreading the digits apart, away from the centerline of the hand or foot.[15]For example, raising the arms up, such as whentightrope-walking, is an example of abduction at theshoulder.[11]When the legs are splayed at the hip, such as when doing astar jumpor doing asplit,the legs are abducted at the hip.[3]
Adductionis a motion that pulls a structure or parttowardsthe midline of the body, or towards the midline of a limb, carried out by one or moreadductormuscles. In the case of fingers and toes, it is bringing the digits together, towards the centerline of the hand or foot. Dropping the arms to the sides, and bringing the knees together, are examples of adduction.[15]
Adduction of thewristis also known asulnar deviationwhich moves the hand towards theulnar styloid(or, towards thelittle finger). Abduction of the wrist is also calledradial deviationwhich moves the hand moving towards theradial styloid(or, towards thethumb).[15][17]
Elevation and depression
editElevation and depressionare movements above and below the horizontal. The words derive from the Latin terms with similar meanings.[c]
Elevationis movement in a superior direction.[19]For example, shrugging is an example of elevation of the scapula.[20]
Depressionis movement in an inferior direction, the opposite of elevation.[21]
Rotation
edit
Rotation of body parts may be internal or external, that is, towards or away from the center of the body.[22]
Internal rotation(medial rotationorintorsion) is rotation towards the axis of the body,[22]carried out byinternal rotators.
External rotation(lateral rotationorextorsion) is rotation away from the center of the body,[22]carried out byexternal rotators.
Internal and external rotators make up therotator cuff,a group of muscles that help to stabilize theshoulder joint.
-
Thelotus positionofyoga,demonstratingexternal rotationof the thigh at the hip. -
Rotating the arm away from the body isexternal rotation. -
Rotating the arm closer to the body isinternal rotation.
Other
edit- Anterogradeandretrogradeflow refer to movement of blood or other fluids in a normal (anterograde) or abnormal (retrograde) direction.[23]
- Circumductionis a conical movement of a body part, such as aball and socket jointor theeye.Circumduction is a combination of flexion, extension, adduction and abduction. Circumduction can be best performed at ball and socket joints, such as thehipandshoulder,but may also be performed by other parts of the body such as fingers, hands, feet, and head.[24]For example, circumduction occurs when spinning the arm when performing a serve intennisor bowling acricket ball.[25]
- Reductionis a motion returning a bone to its original state,[26]such as a shoulder reduction followingshoulder dislocation,or reduction of ahernia.
-
The swinging action made during atennis serveis an example ofcircumduction
Special motion
editHands and feet
editFlexion and extension of the foot
editDorsiflexionandplantar flexionrefer to extension or flexion of the foot at the ankle. These terms refer to flexion in direction of the "back" of the foot, which is the upper surface of the foot when standing, and flexion in direction of the sole of the foot. These terms are used to resolve confusion, as technicallyextensionof the joint is dorsiflexion, which could be considered counter-intuitive as the motion reduces the angle between the foot and the leg.[27]
Dorsiflexionis where the toes are brought closer to theshin.This decreases the angle between the dorsum of the foot and theleg.[28]For example, when walking on theheelsthe ankle is described as being in dorsiflexion.[27]Similarly, dorsiflexion helps in assuming a deepsquat position.[29]
Plantar flexion or plantarflexion is the movement which decreases the angle between the sole of the foot and the back of the leg; for example, the movement when depressing acar pedalor standing on tiptoes.[27]
-
Aballerina,demonstratingplantar flexionof the feet -
Dorsi and plantar flexion of the foot
Flexion and extension of the hand
editPalmarflexion and dorsiflexion refer to movement of the flexion (palmarflexion) or extension (dorsiflexion) of the hand at the wrist.[30]These terms refer to flexion between the hand and the body'sdorsalsurface, which inanatomical positionis considered the back of the arm; and flexion between the hand and the body'spalmarsurface, which in anatomical position is considered the anterior side of the arm.[31]The direction of terms are opposite to those in the foot because ofembryologicalrotation of the limbs in opposite directions.[10]
Palmarflexionis flexion of the wrist towards thepalmandventralside offorearm.[30]
Dorsiflexionishyperextensionof thewristjoint, towards thedorsalside of forearm.[30]
-
Praying HandsbyAlbrecht Dürer,demonstratingdorsiflexionof the hands.
Pronation and supination
editPronationandsupinationrefer generally to theprone(facing down) orsupine(facing up) positions. In the extremities, they are the rotation of the forearm or foot so that in thestandard anatomical positionthe palm or sole is facing anteriorly when in supination and posteriorly when in pronation.[32]As an example, when a person is typing on a computer keyboard, their hands are pronated; when washing their face, they are supinated.
Pronationat theforearmis a rotational movement where the hand and upper arm are turned so the thumbs point towards the body. When the forearm and hand are supinated, the thumbs point away from the body. Pronation of the foot is turning of the sole outwards, so that weight is borne on the medial part of the foot.[33]
Supinationof the forearm occurs when the forearm or palm are rotated outwards. Supination of the foot is turning of the sole of the foot inwards, shifting weight to the lateral edge.[34]
-
Supination and pronation of the foot -
Supination and pronation of the arm
Inversion and eversion
editInversion and eversion are movements that tilt the sole of the foot away from (eversion) or towards (inversion) the midline of the body.[35]
Eversionis the movement of thesole of the footaway from themedian plane.[36] Inversionis the movement of thesoletowards themedian plane.For example, inversion describes the motion when anankle is twisted.[28]
-
Example showing inversion and eversion of the foot -
Eversion of the right foot -
Inversion of the right foot
Eyes
editUnique terminology is also used to describe the eye. For example:
- Aversionis an eye movement involving botheyesmoving synchronously and symmetrically in the same direction.[37]
- Torsionis eye movement that affects the vertical axis of the eye,[38]such as the movement made when looking in to the nose.
Jaw and teeth
edit- Occlusionis motion of themandibulatowards themaxillamaking contact between the teeth.[39]
- Protrusionandretrusionare sometimes used to describe the anterior (protrusion) and posterior (retrusion) movement of the jaw.[40]
-
Examples showing protrusion and retrusion. -
Elevation and depression of the jaw.
Other
editOther terms include:
- Nutationandcounternutation[d]are movement of thesacrumdefined by the rotation of thepromontorydownwards and anteriorly, as with lumbar extension (nutation); or upwards and posteriorly, as with lumbar flexion (counternutation).[42]
- Oppositionis the movement that involves grasping of the thumb and fingers.[43]
- Protractionandretractionis an anterior (protraction) or posterior (retraction) movement,[44]such as of the arm at the shoulders, although these terms have been criticised as non-specific.[45]
- Reciprocal motionis alternating motions in opposing directions.[46]
- Repositionis restoring an object to its natural condition.[47]
-
Nutation at left, counternutation at right -
An example ofopposition -
Example ofoppositionof the thumb and index finger
See also
editNotes
editReferences
edit- ^abcMarieb 2010,p. 212.
- ^abcLippert 2011,pp. 6–7.
- ^abcKendall 2005,p. 57.
- ^Lippert 2011,pp. 1–7.
- ^Kendall 2005,p. G-4.
- ^Seeley 1998,p. 229.
- ^"Anatomy & Physiology".Openstax college at Connexions.Archivedfrom the original on June 29, 2014.RetrievedNovember 16,2013.
- ^OED 1989,"flexion", "extension".
- ^OED 1989,"flexion".
- ^abcdKendall 2005,p. 56.
- ^abcCook 2012,pp. 180–193.
- ^OED 1989,"extension".
- ^Kendall 2005.
- ^Platzer 2004,p. 258.
- ^abcdSwartz 2010,pp. 590–591.
- ^OED 1989,"adduction", "abduction", "abduct".
- ^See:for appropriate imageArchived2015-12-22 at theWayback Machine
- ^OED 1989.
- ^OED 1989,"elevation".
- ^Kendall 2005,p. 303.
- ^OED 1989,"depression".
- ^abcSwartz 2010,pp. 590–1.
- ^OED 1989,"anterograde", "retrograde".
- ^Saladin 2010,p. 300.
- ^Kendall 2005,p. 304.
- ^Taber 2001,"reduction".
- ^abcKendall 2005,p. 371.
- ^abKyung 2005,p. 123.
- ^Kasuyama, Tatsuya; Sakamoto, Masaaki; Nakazawa, Rie (2009)."Ankle Joint Dorsiflexion Measurement Using the Deep Squatting Posture".Journal of Physical Therapy Science.21(2): 195–199.doi:10.1589/jpts.21.195.Archivedfrom the original on 2024-05-23.Retrieved2024-05-23.
- ^abcSwartz 2010,pp. 591–593.
- ^OED 1989,"palmarflexion", "dorsiflexion".
- ^Swartz 2010,pp. 591–592.
- ^OED 1989,"pronation".
- ^OED 1989,"supination".
- ^Swartz 2010,p. 591.
- ^Kyung 2005,p. 108.
- ^DMD 2012,"version".
- ^Taber 2001,"torsion".
- ^Taber 2001,"occlusion".
- ^Taber 2001,"protrusion", "retrusion".
- ^OED 1989,"nutation".
- ^Houglum 2012,p. 333.
- ^Taber 2001,"opposition".
- ^OED 1989,"protraction", "retraction".
- ^Kendall 2005,p. 302.
- ^Taber 2001,"reciprocation".
- ^OED 1989,"resposition".
Sources
edit- Albert, Daniel (2012).Dorland's Illustrated Medical Dictionary(32nd ed.). Philadelphia, PA: Saunders/Elsevier.ISBN978-1416062578.
- Chung, Kyung Won (2005).Gross Anatomy (Board Review).Lippincott Williams & Wilkins.ISBN0-7817-5309-0.
- Cook, Chad E. (2012).Orthopedic Manual Therapy: An Evidence Based Approach(2nd ed.). Upper Saddle River, NJ: Pearson Education.ISBN978-0-13-802173-3.
- Houglum, Peggy A.; Bertoli, Dolores B. (2012).Brunnstrom's Clinical Kinesiology.F. A. Davis Company.ISBN978-0-8036-2352-1.
- Kendall, Florence Peterson; et al. (2005).Muscles: testing and function with posture and pain(5th ed.). Baltimore, MD: Lippincott Williams & Wilkins.ISBN0-7817-4780-5.
- Lippert, Lynn S. (2011).Clinical Kinesiology and Anatomy(5th ed.). F. A. Davis Company.ISBN978-0-8036-2363-7.
- Marieb, Elaine N.; Wilhelm, Patricia B.; Mallat, Jon (2010).Human Anatomy.Pearson.ISBN978-0-321-61611-1.
- Platzer, Werner (2004).Color Atlas of Human Anatomy, Vol. 1: Locomotor System(5th ed.). Thieme.ISBN3-13-533305-1.
- Saladin, Kenneth S. (2010).Anatomy & Physiology The Unity of Form and Function(5th ed.). McGraw Hill.ISBN978-0077361358.
- Seeley, Rod R.; Stephens, Trent D.; Tate, Philip (1998).Anatomy & Physiology(4th ed.). WCB/McGraw-Hill.ISBN0-697-41107-9.
- Simpson, John A.; Weiner, Edmung (1989).The Oxford English Dictionary.Oxford: Clarendon Press.ISBN9780198611868.
- Swartz, Mark H. (2010).Textbook of Physical Diagnosis: History and Examination(6th ed.). Saunders/Elsevier.ISBN978-1-4160-6203-5.
- Venes, Donald; Thomas, Clayton L., eds. (2001).Taber's Cyclopedic Medical Dictionary(illustrated in full color 19th ed.). Philadelphia: F. A. Davis Co.ISBN0-8036-0655-9.
External links
edit