Fwd: Re: Reply to Inversion, Supination and Other Friends
Beverly Cusick, MS PT
Description
Collection
Title:
Fwd: Re: Reply to Inversion, Supination and Other Friends
Creator:
Beverly Cusick, MS PT
Date:
12/17/2001
Text:
Original posting from Dr. Mel C. Siff to the Physio listserv:
>At 11:22 AM 12/15/01 -0500, you wrote:
>>Recently, this comment was made on one of this or another similar list:
>>
>><Pronation is not a single plane movement, it is triplanar. It combines
>>components of eversion, abduction and dorsiflexion of the lower segment of
>>the foot in open chain. In closed chain, the calcaneus everts under the
>>talus and the talus plantarflexes, adducts and glides foward on the
>>calcaneus. The floor abducts and dorsiflexes
>>the forefoot around the mid-talar joint (MTJ) oblique axis, and inverts the
>>forefoot around the MTJ longitudinal axis. (Cusick, 1995) >
>
>Hi Dr. Mel -
>
>Cusick here... And for 30 years I've wrestled with the considerable
>difference of opinion regarding the disposition of the foot during various
>activities. As an instructor, I have found that by observing the
>movements of the various foot joints as they occur in each of the three
>cardinal planes, I can grant clarity to the relevance of axial
>inclination, to the variances that are seen in the same deviations into
>pronation and supination as evidence of planar dominance, and to deriving
>a plan for restoring a more ideal alignment while molding a cast for an
>orthosis, a splint, or a series of casts.
>
>I did not define pronation and supination as entire lower limb actions
>because I was discussing them at the foot - not the forearm - at the time.
>And their influences on leg, knee, and hip motions are worth noting in a
>discussion of the closed chain, but not in the definition.
>
>As Christmas is looming and my daughter is 4, I'm not prepared to launch a
>dissertation on this topic at the moment, but I do urge any who are
>interested in this issue to go to my website, where I've posted a lengthy
>discussion of the nomenclature
>and an offer to participate in the honing of it into a meaningful body of
>terms. www.gaitways.com .
>
>So Happy Holidays!! I'll be back on the case in a week or so!
>
>Regards -
>
>Beverly Cusick, PT, MS
>
>
>Mel again....
>>*** This comment is very important to note, because there is often
>>considerable difference of opinion regarding the disposition of the foot
>>during various activities. Many authors refer quite casually to foot
>>problems being caused by excessive pronation or supination of the foot, but
>>others point out that these terms are inaccurate and should be replaced by
>>eversion and inversion, respectively.
>>
>>That physio comment above, while correct in stressing the triplanar aspects
>>of pronation, at the very least should rather have stated that what is
>>commonly referred to as pronation of the foot involves triplanar actions of
>>the entire lower extremity.
>>
>>According to the basic definitions, pronation takes place about a single axis
>>(along the length of the foot or hand) and simply means the turning over of
>>the surface of the hands or feet so that their surfaces face partially or
>>fully downwards, while supination refers to the turning over of those
>>surfaces to face upwards. In other words, pronation and supination are
>>defined as uniplanar actions.
>>
>>On the other hand, eversion, ostensibly simply meaning a turning outwards
>>and inversion, ostensibly meaning a turning inwards, are terms that have
>>never been defined as uniplanar actions along a single given axis, since they
>>involve action of all joints of the lower extremities in several planes.
>>Eversion certainly does not refer to rotation about the axis of the leg or
>>the arm, since that action is known as internal or external rotation, nor
>>does it refer to inward or outward displacement to or away from the midline
>>of the body, since those actions are adduction or abduction. Finally,
>>eversion and inversion do not refer to rotation of the foot about a specific
>>axis of the ankle, since those actions are known as plantarflexion or
>>dorsiflexion.
>>
>>In other words, inversion and eversion have never been defined to be any form
>>of uniplanar action, so it would be interesting to know where the notion
>>arose that regards these actions as being some special fundamental joint
>>action. This view suggests that eversion and inversion, like flexion,
>>internal rotation and abduction, are fundamental actions about a given joint
>>that involve no actions about any other axes, but they are not, as the above
>>process of reductio ad absurdum has shown.
>>
>>Eversion is a complex action involving pronation, lateral rotation, valgus
>>(knee knocking), dorsiflexion and adduction of the various joints of the
>>lower extremity in open chain situations, whereas inversion involves the
>>inverse of all of those actions. Presumably one could also refer to
>>eversion, inversion, pronation and supination of the upper extremities if one
>>were standing or walking on the hands, as is the case in gymnastics and
>>circus acts.
>>
>>Thus, if one attributes knee injuries to excessive pronation, this may be
>>profoundly misleading, since what one believes to be simple pronation
>>invariably involves differing degrees of angular displacement of all joints
>>of the lower extremity. For example, one may pronate with the knees pointing
>>directly forwards, outwards or even inwards with significant valgus (noting
>>that 'pure' pronation of the sole of the foot is not possible with the knees
>>fully extended); the consequences for the knees will be very different.
>>Incidentally, the last mentioned situation represents potentially the most
>>harmful posture for activities such as running and squatting.
>>
>>Dr Mel C Siff
>>Denver, USA
>> <URL Redacted>
>At 11:22 AM 12/15/01 -0500, you wrote:
>>Recently, this comment was made on one of this or another similar list:
>>
>><Pronation is not a single plane movement, it is triplanar. It combines
>>components of eversion, abduction and dorsiflexion of the lower segment of
>>the foot in open chain. In closed chain, the calcaneus everts under the
>>talus and the talus plantarflexes, adducts and glides foward on the
>>calcaneus. The floor abducts and dorsiflexes
>>the forefoot around the mid-talar joint (MTJ) oblique axis, and inverts the
>>forefoot around the MTJ longitudinal axis. (Cusick, 1995) >
>
>Hi Dr. Mel -
>
>Cusick here... And for 30 years I've wrestled with the considerable
>difference of opinion regarding the disposition of the foot during various
>activities. As an instructor, I have found that by observing the
>movements of the various foot joints as they occur in each of the three
>cardinal planes, I can grant clarity to the relevance of axial
>inclination, to the variances that are seen in the same deviations into
>pronation and supination as evidence of planar dominance, and to deriving
>a plan for restoring a more ideal alignment while molding a cast for an
>orthosis, a splint, or a series of casts.
>
>I did not define pronation and supination as entire lower limb actions
>because I was discussing them at the foot - not the forearm - at the time.
>And their influences on leg, knee, and hip motions are worth noting in a
>discussion of the closed chain, but not in the definition.
>
>As Christmas is looming and my daughter is 4, I'm not prepared to launch a
>dissertation on this topic at the moment, but I do urge any who are
>interested in this issue to go to my website, where I've posted a lengthy
>discussion of the nomenclature
>and an offer to participate in the honing of it into a meaningful body of
>terms. www.gaitways.com .
>
>So Happy Holidays!! I'll be back on the case in a week or so!
>
>Regards -
>
>Beverly Cusick, PT, MS
>
>
>Mel again....
>>*** This comment is very important to note, because there is often
>>considerable difference of opinion regarding the disposition of the foot
>>during various activities. Many authors refer quite casually to foot
>>problems being caused by excessive pronation or supination of the foot, but
>>others point out that these terms are inaccurate and should be replaced by
>>eversion and inversion, respectively.
>>
>>That physio comment above, while correct in stressing the triplanar aspects
>>of pronation, at the very least should rather have stated that what is
>>commonly referred to as pronation of the foot involves triplanar actions of
>>the entire lower extremity.
>>
>>According to the basic definitions, pronation takes place about a single axis
>>(along the length of the foot or hand) and simply means the turning over of
>>the surface of the hands or feet so that their surfaces face partially or
>>fully downwards, while supination refers to the turning over of those
>>surfaces to face upwards. In other words, pronation and supination are
>>defined as uniplanar actions.
>>
>>On the other hand, eversion, ostensibly simply meaning a turning outwards
>>and inversion, ostensibly meaning a turning inwards, are terms that have
>>never been defined as uniplanar actions along a single given axis, since they
>>involve action of all joints of the lower extremities in several planes.
>>Eversion certainly does not refer to rotation about the axis of the leg or
>>the arm, since that action is known as internal or external rotation, nor
>>does it refer to inward or outward displacement to or away from the midline
>>of the body, since those actions are adduction or abduction. Finally,
>>eversion and inversion do not refer to rotation of the foot about a specific
>>axis of the ankle, since those actions are known as plantarflexion or
>>dorsiflexion.
>>
>>In other words, inversion and eversion have never been defined to be any form
>>of uniplanar action, so it would be interesting to know where the notion
>>arose that regards these actions as being some special fundamental joint
>>action. This view suggests that eversion and inversion, like flexion,
>>internal rotation and abduction, are fundamental actions about a given joint
>>that involve no actions about any other axes, but they are not, as the above
>>process of reductio ad absurdum has shown.
>>
>>Eversion is a complex action involving pronation, lateral rotation, valgus
>>(knee knocking), dorsiflexion and adduction of the various joints of the
>>lower extremity in open chain situations, whereas inversion involves the
>>inverse of all of those actions. Presumably one could also refer to
>>eversion, inversion, pronation and supination of the upper extremities if one
>>were standing or walking on the hands, as is the case in gymnastics and
>>circus acts.
>>
>>Thus, if one attributes knee injuries to excessive pronation, this may be
>>profoundly misleading, since what one believes to be simple pronation
>>invariably involves differing degrees of angular displacement of all joints
>>of the lower extremity. For example, one may pronate with the knees pointing
>>directly forwards, outwards or even inwards with significant valgus (noting
>>that 'pure' pronation of the sole of the foot is not possible with the knees
>>fully extended); the consequences for the knees will be very different.
>>Incidentally, the last mentioned situation represents potentially the most
>>harmful posture for activities such as running and squatting.
>>
>>Dr Mel C Siff
>>Denver, USA
>> <URL Redacted>
Citation
Beverly Cusick, MS PT, “Fwd: Re: Reply to Inversion, Supination and Other Friends,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 7, 2024, https://library.drfop.org/items/show/217714.
