Effect of patient position on the consistency of placing the rearfoot at subtalar neutral

1997 ◽  
Vol 87 (9) ◽  
pp. 399-406 ◽  
Author(s):  
MR Pierrynowski ◽  
SB Smith
Keyword(s):  
Prone Position ◽  
Visual Cues ◽  
Neutral Position ◽  
Relative Importance ◽  
Position Preference ◽  
Foot Care ◽  
Patient Position ◽  
Foot Orthosis

The ability of foot care specialists to place a rearfoot at the subtalar neutral position is important for the care of patients who require foot orthosis prescription, fabrication, and management. Although some clinicians perform this procedure with the patient in the prone position, others prefer a seated or standing approach. This study examined whether patient position and preferred patient position influence the ability of clinicians to place a subject's rearfoot at the subtalar neutral position. The results suggest the following: a clinician's ability to find the subtalar neutral position is better with a seated subject; clinicians do not necessarily perform better assessments on a subject in a position corresponding to their patient position preference; and clinicians who prefer their patients prone generally have more flexible and reproducible observations. In addition, the findings suggest that the nature and relative importance of the tactile and visual cues used by clinicians to place a rearfoot at the subtalar neutral position warrant further exploration.

Proficiency of foot care specialists to place the rearfoot at subtalar neutral

1996 ◽  
Vol 86 (5) ◽  
pp. 217-223 ◽  
Author(s):  
MR Pierrynowski ◽  
SB Smith ◽  
JH Mlynarczyk
Keyword(s):  
Lower Extremity ◽  
Neutral Position ◽  
Foot Care ◽  
Physiotherapy Students ◽  
Foot Orthosis ◽  
Better Than

The proficiency of clinicians to place a rearfoot at the subtalar neutral position is important for the treatment of patients with lower extremity dysfunctions, and especially for foot orthosis prescription, fabrication, and management. However, the ability of experienced foot care specialists to perform this task has not been statistically compared with an average capacity. In this study, eight experienced chiropodists and eight untrained physiotherapy students placed six rearfeet at the subtalar neutral position five times. Statistically, the foot care specialists were able to find the subtalar neutral position better than the students (mean 0.00 versus 0.99 degrees, SD 1.84 versus 2.97 degrees, range -5.27 degrees to 4.33 degrees versus -6.25 degrees to 9.27 degrees). This can be interpreted as stating that foot care specialists and untrained students place a rearfoot within +/- 1 degree of the subtalar neutral position 41.3% and 25.0% of the time, respectively. Corresponding values within +/- 2 degrees of the subtalar neutral position are 72.3 degrees and 47.6 degrees, respectively. Alternatively, it can be stated that experienced foot care specialists are within +/- 3.0 degrees of the subtalar neutral position 90% of the time. A corresponding value for the students is +/- 4.9 degrees. These results suggest that although experienced foot care specialists position a rearfoot at the subtalar neutral position better than untrained physiotherapy students, there is room for improvement.

Rear Foot Inversion/Eversion During Gait Relative to the Subtalar Joint Neutral Position

1996 ◽  
Vol 17 (7) ◽  
pp. 406-412 ◽  
Author(s):  
Michael Raymond Pierrynowski ◽  
Steve Barry Smith
Keyword(s):  
Subtalar Joint ◽  
Three Dimensional ◽  
Neutral Position ◽  
Foot Care ◽  
Worst Case ◽  
Foot Motion ◽  
Rear Part ◽  
Valid Estimate ◽  
Foot Position ◽  
Foot Orthotic

Clinicians often fabricate foot orthotic devices at the subtalar joint neutral position (STNP) to mimic the position of the rear foot during midstance. However, rear foot motion during gait, relative to the resting standing foot position, not the STNP, is often reported in the literature. The motion of the rear foot relative to a valid estimate of the STNP is unknown. In this study, six experienced foot care specialists manually placed the rear part of the feet of nine subjects at the STNP seven or eight times to obtain a valid estimate of each subject's STNP. The worst-case mean and 95% confidence interval of the STNP estimate for any one subject was 0.0° ± 0.7°. These nine subjects then walked on a motor-driven treadmill, set at 0.89 meters/sec, and three-dimensional estimates of each subject's rear foot inversion/eversion motion were obtained, then averaged over 6 to 26 strides. For most subjects, the rear foot was always everted during stance with mean and standard deviation maximal eversion (7.2° ± 1.2°) occurring at 44% of the total gait cycle. The inversion/eversion orientation during swing was characterized by 1 ° to 2° of eversion, with a small amount of inversion in early swing. These findings have implications for the fabrication of foot orthoses, since the rear foot is rarely near the STNP during stance.

Blind intubation through an i-gel® in the prone position: A prospective cohort study

2020 ◽  
Vol 48 (6) ◽  
pp. 439-443
Author(s):  
Maarten van Dijck ◽  
Bernard M Houweling ◽  
Mark V Koning
Keyword(s):  
Success Rate ◽  
Prone Position ◽  
Medical Emergency ◽  
Neutral Position ◽  
Lumen Tube ◽  
Low Resource ◽  
The Third ◽  
Trial Register ◽  
Single Lumen ◽  
A Prospective Study

Accidental extubation in the prone position is a medical emergency in which quick and low resource demanding airway management is required. Regaining oxygenation is the primary goal, but sometimes intubation may be required to regain oxygenation. Blind intubation through an i-gel® (Intersurgical Ltd, Wokingham, Berkshire, UK) may be a quick and low resource demanding method. However, the success rate of the use of an i-gel as an intubation conduit in the prone position is unknown. This was a prospective study in patients scheduled for lumbar surgery. General anaesthesia was induced in the prone position and an i-gel was inserted. After successful ventilation, up to three attempts at intubation using a VivaSight-SL single-lumen tube (Ambu A/S, Ballerup, Denmark) were performed. The first attempt was blinded for the operator and the patient’s head was in a neutral position. The second attempt was blinded for the operator with the patient’s head rotated laterally. The third attempt was on-screen and allowed various manoeuvres to facilitate intubation. A success rate of 70% was deemed clinically acceptable. The study was terminated early after 14 subjects because the success rate of 70% was not achievable. However, ventilation using the i-gel in the prone position was successful in 13 patients (93%). Intubation was successful in only one patient at the first attempt, one patient at the second attempt and three patients at the third attempt. Overall, the success rate was 36%. Blind intubation using an i-gel as an intubation conduit in the prone position is not recommended. Netherlands Trial Register number NL6387 (NTR7659).

Multimodal signalling: the relative importance of chemical and visual cues from females to the behaviour of male wolf spiders (Lycosidae)

2009 ◽  
Vol 77 (4) ◽  
pp. 937-947 ◽  
Author(s):  
Ann L. Rypstra ◽  
Ann M. Schlosser ◽  
Patrick L. Sutton ◽  
Matthew H. Persons
Keyword(s):  
Visual Cues ◽  
Relative Importance ◽  
Wolf Spiders ◽  
Multimodal Signalling

scholarly journals Loss of intraoperative neurological monitoring signals during flexed prone positioning on a hinged open frame during surgery for kyphoscoliosis correction: case report

2018 ◽  
Vol 29 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Randall B. Graham ◽  
Mathew Cotton ◽  
Antoun Koht ◽  
Tyler R. Koski
Keyword(s):  
Case Report ◽  
Evoked Potentials ◽  
Prone Position ◽  
Spine Surgery ◽  
Complete Loss ◽  
Neurological Deficits ◽  
Neutral Position ◽  
Careful Attention ◽  
Prone Positioning ◽  
Neural Monitoring

Various complications of prone positioning in spine surgery have been described in the literature. Patients in the prone position for extended periods are subject to neurological deficits and/or loss of intraoperative signals due to compression neuropathies, but positioning-related spinal deficits are rare in the thoracolumbar deformity population. The authors present a case of severe kyphoscoliotic deformity with critical thoracolumbar stenosis in which, during the use of a hinged open frame in the prone position, complete loss of intraoperative neural monitoring signals occurred while the frame was flexed into kyphosis to facilitate exposure and instrumentation placement. When the frame was reset to a neutral position, evoked potentials returned to baseline and the operation proceeded without complications. This case represents, to the authors’ knowledge, the first report of loss of evoked potentials due to an alteration of prone positioning on a hinged open frame. When positioning patients in such a manner, careful attention should be directed to intraoperative signals in patients with critical stenosis and kyphotic deformity.

Relative role of visual and non-visual cues in determining the direction of “up”: Experiments in the York tilted room facility

2003 ◽  
Vol 13 (4-6) ◽  
pp. 287-293
Author(s):  
H.L. Jenkin ◽  
R.T. Dyde ◽  
M.R. Jenkin ◽  
I.P. Howard ◽  
L.R. Harris
Keyword(s):  
Surface Structure ◽  
Interior Design ◽  
Visual Cues ◽  
Human Performance ◽  
Body Orientation ◽  
Relative Role ◽  
Relative Importance ◽  
Relative Significance ◽  
The Subject

Perceiving a direction as “up” is fundamental to human performance and perception. Astronauts in microgravity frequently experience reorientation illusions in which they, or their world, appear to flip and ‘up’ becomes arbitrarily redefined. This paper assesses the relative importance of visual cues in determining the perceived up direction. In the absence of information about the origin of illumination, people interpret surface structure by assuming that the direction of illumination is from above. Here we exploit this phenomenon to measure the influence of head and body orientation, gravity and visual cues on the perceived up direction. Fifteen subjects judged the shape of shaded circles presented in various orientations. The circles were shaded in such a way that when the shading was compatible with light coming from above, the circle appeared as a convex hemisphere. Therefore, by finding which shaded circle appeared most convex, we can deduce the direction regarded as “up”. The different cues contributing to this percept were separated by varying both the orientation of the subject and the surrounding room relative to gravity. The relative significance of each cue may be of use in spacecraft interior design to help reduce the incidence of visual reorientation illusions.

Effects of joint alignment and type on mechanical properties of thermoplastic articulated ankle-foot orthosis

2011 ◽  
Vol 35 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Fan Gao ◽  
William Carlton ◽  
Susan Kapp
Keyword(s):  
Mechanical Properties ◽  
Ankle Joint ◽  
Plantar Flexion ◽  
Skin Irritation ◽  
Neutral Position ◽  
Motor Shaft ◽  
Ankle Foot Orthosis ◽  
Resistance Torque ◽  
Flexure Joints ◽  
Foot Orthosis

Background: Articulated or hinged ankle-foot orthosis (AFO) allow more range of motion. However, quantitative investigation on articulated AFO is still sparse.Objective: The objective of the study was to quantitatively investigate effects of alignment and joint types on mechanical properties of the thermoplastic articulated AFO.Study design: Tamarack dorsiflexion assist flexure joints with three durometers (75, 85 and 95) and free motion joint were tested. The AFO joint was aligned with the center of the motor shaft (surrogate ankle joint), 10 mm superior, inferior, anterior and posterior with respect to the motor shaft center.Methods: The AFO was passively moved from 20° plantar flexion to 15° dorsiflexion at a speed of 10°/s using a motorized device. Mechanical properties including index of hysteresis, passive resistance torque and quasi-static stiffness (at neutral, 5°, 10° and 15° in plantar flexion) were quantified.Results: Significant effects of joint types and joint alignment on the mechanical properties of an articulated thermoplastic AFO were revealed. Specifically, center alignment showed minimum resistance and stiffness while anterior and posterior alignment showed significantly higher resistance and stiffness. The dorsiflexion assist torques at neutral position ranged from 0.69 ± 0.09 to 1.88 ± 0.10 Nm.Conclusions: Anterior and posterior alignment should be avoided as much as possible.Clinical relevanceThe current study suggested that anterior and posterior alignment be avoided as much as possible in clinical practice due to potential skin irritation and increase in stress around the ankle joint.

scholarly journals The use of chemical and visual cues in female choice in the butterfly Bicyclus anynana

2007 ◽  
Vol 274 (1611) ◽  
pp. 845-851 ◽  
Author(s):  
Katie Costanzo ◽  
Antónia Monteiro
Keyword(s):  
Female Choice ◽  
Visual Cues ◽  
Chemical Cues ◽  
Chemical Signals ◽  
Relative Importance ◽  
Bicyclus Anynana ◽  
Closely Related Species ◽  
Multiple Cues ◽  
The Past ◽  
Close Range

Investigating the relative importance of multiple cues for mate choice within a species may highlight possible mechanisms that led to the diversification of closely related species in the past. Here, we investigate the importance of close-range pheromones produced by male Bicyclus anynana butterflies and determine the relative importance of these chemical cues versus visual cues in sexual selection by female choice. We first blocked putative androconial organs on the fore- and hindwings of males, while also manipulating the ability of females to perceive chemical signals via their antenna. We found that male chemical signals were emitted by both fore- and hindwing pairs and that they play an important role in female choice. We subsequently tested the relative importance of these chemical cues versus visual cues, previously identified for this species, and found that they play an equally important role in female choice in our laboratory setting. In addition, females will mate with males with only one signal present and blocking both androconial organs on males seems to interfere with male to male recognition. We discuss the possible functions of these signals and how this bimodal system may be used in intra- and interspecific mate evaluation.

2D vs. 3D Visual Cues for Altitude Maintenance in Low-Altitude Flight

2007 ◽  
Vol 51 (19) ◽  
pp. 1287-1290
Author(s):  
Rob Gray
Keyword(s):  
Visual Cues ◽  
Motion Parallax ◽  
Visual Scene ◽  
Relative Importance ◽  
Object Position ◽  
Low Level ◽  
3D Objects ◽  
Level Flight ◽  
Low Altitude ◽  
2D And 3D

Previous research on altitude maintenance in low-altitude flight has focused either on cues provided by 2D features in the visual scene (e.g., splay angle) or on visual cues provided by the presence of 3D objects in the scene (e.g., occlusion). Therefore, little is known about the relative importance of 2D and 3D cues in altitude maintenance. We systematically varied the position variability, height, and pattern of surface elements in a simulated low-level flight environment to vary the salience of 2D and 3D visual cues. For 2D objects, altitude variability increased as a function of object position variability indicating that splay and depression angles are not reliable cues for terrains with irregularly spaced objects. For 3D objects, altitude variability increased less (or not at all) as a function of position variability indicating that the cues provided by 3D objects such as occlusion and motion parallax are the dominant visual cues for altitude maintenance for natural terrains with irregularly spaced objects.

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