Haptic Stabilization of Posture: Changes in Arm Proprioception and Cutaneous Feedback for Different Arm Orientations

1999 ◽  
Vol 82 (6) ◽  
pp. 3541-3549 ◽  
Author(s):  
Ely Rabin ◽  
Simone B. Bortolami ◽  
Paul DiZio ◽  
James R. Lackner
Keyword(s):  
Postural Sway ◽  
Center Of Pressure ◽  
Body Position ◽  
Geometric Analysis ◽  
Body Sway ◽  
Proprioceptive Information ◽  
Foot Pressure ◽  
Somatosensory Information ◽  
Cutaneous Feedback ◽  
Postural Stabilization

Postural sway during quiet stance is attenuated by actively maintained contact of the index finger with a stationary surface, even if the level of applied force (<1 N) cannot provide mechanical stabilization. In this situation, changes in force level at the fingertip lead changes in center of foot pressure by ∼250 ms. These and related findings indicate that stimulation of the fingertip combined with proprioceptive information about the hand and arm can serve as an active sensor of body position relative to the point of contact. A geometric analysis of the relationship between hand and torso displacement during body sway led to the prediction that arm and hand proprioceptive and finger somatosensory information about body sway would be maximized with finger contact in the plane of body sway. Therefore, the most postural stabilization should be possible with such contact. To test this analysis, subjects touched a laterally versus anteriorly placed surface while in each of two stances: the heel-to-toe tandem Romberg stance that reduces medial-lateral stability and the heel-to-heel, toes-outward, knees-bent, “duck stance” that reduces fore-aft stability. Postural sway was always least with finger contact in the unstable plane: for the tandem stance, lateral fingertip contact was significantly more effective than frontal contact, and, for the duck stance, frontal contact was more effective than lateral fingertip contact. Force changes at the fingertip led changes in center of pressure of the feet by ∼250 ms for both fingertip contact locations for both test stances. These results support the geometric analysis, which showed that 1) arm joint angles change by the largest amount when fingertip contact is maintained in the plane of greatest sway, and 2) the somatosensory cues at the fingertip provide both direction and amplitude information about sway when the finger is contacting a surface in the unstable plane.

Postural sway with earth-fixed and body-referenced finger contact in young and older adults

1999 ◽  
Vol 9 (2) ◽  
pp. 103-109
Author(s):  
Reginald L. Reginella ◽  
Mark S. Redfern ◽  
Joseph M. Furman
Keyword(s):  
Older Adults ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Postural Control System ◽  
Fixed Reference ◽  
Older Subjects

Sensory information from lightly touching a reference with the hand is known to influence postural sway in young adults. The primary aim of this study was to compare the influence of finger contact (FC) with an earth-fixed reference to the influence of FC with a body-fixed reference. A second goal of this study was to determine if FC is used differently by older adults compared to younger adults. Using a force plate, center of pressure at the feet was recorded from blindfolded young and older subjects during several conditions. Subjects either did or did not lightly touch a force-sensitive plate that was either earth-fixed or moved forward and backward in synchrony with body sway (that is, sway-referenced). In addition, support surface conditions were also varied, including a fixed floor and a sway-referenced floor using an EquitestTM. Results showed that the type of FC, floor condition, and age each had an effect on postural sway. Touching an earth-fixed plate decreased postural sway as compared to no touching, while touching a sway-referenced plate incresased sway. This influence of FC was enhanced when the floor was sway-referenced. Although older subjects swayed more than young subjects overall, no age-FC interactions occurred, indicating that FC was not utilized differently between the age groups. This study suggests that FC cannot be disregarded as erroneous, especially when proprioceptive information from the legs is distorted. Further, FC is integrated with other sensory information by the postural control system similarly in young and older persons.

scholarly journals Firing properties of muscle spindles supplying the intrinsic foot muscles of humans in unloaded and freestanding conditions

2019 ◽  
Vol 121 (1) ◽  
pp. 74-84 ◽  
Author(s):  
T. P. Knellwolf ◽  
A. R. Burton ◽  
E. Hammam ◽  
V. G. Macefield
Keyword(s):  
Muscle Spindle ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Muscle Spindles ◽  
Medial Malleolus ◽  
Proprioceptive Information ◽  
Muscle Spindle Afferents ◽  
Tungsten Microelectrode ◽  
Firing Properties ◽  
Intrinsic Muscles

We recently developed an approach for recording from muscle spindles in the intrinsic muscles of the foot in freestanding humans by inserting a tungsten microelectrode into the posterior tibial nerve behind the medial malleolus of the ankle. Here we characterize the behavior of muscle spindles in the small muscles of the foot in 1) seated subjects with the leg horizontal and the foot naturally plantarflexed and 2) standing subjects. In the first study, recordings were made from 26 muscle spindle afferents located within flexor digiti minimi brevis ( n = 4), abductor digiti minimi ( n = 3), quadratus plantae ( n = 3), plantar interossei ( n = 4), flexor digitorum brevis ( n = 3), dorsal interossei ( n = 2), and lumbricals ( n = 2), with one each supplying abductor hallucis, adductor hallucis, and flexor hallucis brevis. The identity of another two muscle afferents was unknown. The majority of the units were silent at rest, only seven (27%) being spontaneously active. Because of the anatomic constraints of the foot, some spindles supplying muscles acting on the toes responded to movements of one or more digits. In the second study, 12 muscle spindle afferents were examined during standing. The ongoing discharge of eight spindle afferents covaried with changes in the center of pressure during postural sway. We conclude that the majority of spindle endings in the small muscles of the foot are silent at rest, which may allow them to encode changes in conformation of the foot when it is loaded during standing. Moreover, these muscle spindle afferents can provide useful proprioceptive information during standing and postural sway. NEW & NOTEWORTHY We have characterized the firing properties of muscle spindles in the intrinsic muscles of the human foot for the first time. The majority of the spindle endings are silent in seated subjects, and most fire tonically during standing, their discharge covarying with center of pressure during postural sway. We conclude that spindle endings in the intrinsic muscles of the foot provide useful proprioceptive information during free standing.

Influences of Arm Proprioception and Degrees of Freedom on Postural Control With Light Touch Feedback

2008 ◽  
Vol 99 (2) ◽  
pp. 595-604 ◽  
Author(s):  
Ely Rabin ◽  
Paul DiZio ◽  
Joel Ventura ◽  
James R. Lackner
Keyword(s):  
Postural Control ◽  
Degrees Of Freedom ◽  
Biceps Brachii ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Tactile Feedback ◽  
Contact Forces ◽  
Light Touch ◽  
Postural Stabilization ◽  
And Control

Lightly touching a stable surface with one fingertip strongly stabilizes standing posture. The three main features of this phenomenon are fingertip contact forces maintained at levels too low to provide mechanical support, attenuation of postural sway relative to conditions without fingertip touch, and center of pressure (CP) lags changes in fingertip shear forces by ∼250 ms. In the experiments presented here, we tested whether accurate arm proprioception and also whether the precision fingertip contact afforded by the arm's many degrees of freedom are necessary for postural stabilization by finger contact. In our first experiment, we perturbed arm proprioception and control with biceps brachii vibration (120-Hz, 2-mm amplitude). This degraded postural control, resulting in greater postural sway amplitudes. In a second study, we immobilized the touching arm with a splint. This prevented precision fingertip contact but had no effect on postural sway amplitude. In both experiments, the correlation and latency of fingertip contact forces to postural sway were unaffected. We conclude that postural control is executed based on information about arm orientation as well as tactile feedback from light touch, although precision fingertip contact is not essential. The consistent correlation and timing of CP movement and fingertip forces across conditions in which postural sway amplitude and fingertip contact are differentially disrupted suggests posture and the fingertip are controlled in parallel with feedback from the fingertip in this task.

Position and Velocity Coupling of Postural Sway to Somatosensory Drive

1998 ◽  
Vol 79 (4) ◽  
pp. 1661-1674 ◽  
Author(s):  
John Jeka ◽  
Kelvin Oie ◽  
Gregor Schöner ◽  
Tjeerd Dijkstra ◽  
Elaine Henson
Keyword(s):  
Contact Surface ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Somatosensory System ◽  
Moving Frame ◽  
Body Sway ◽  
Driving Frequency ◽  
Moving Contact ◽  
Spatial Reference Frame

Jeka, John, Kelvin Oie, Gregor Schöner, Tjeerd Dijkstra, and Elaine Henson. Position and velocity coupling of postural sway to somatosensory drive. J. Neurophysiol. 79: 1661–1674, 1998. Light touch contact of a fingertip to a stationary surface provides orientation information that enhances control of upright stance. Slight changes in contact force at the fingertip lead to sensory cues about the direction of body sway, allowing attenuation of sway. In the present study, the coupling of postural sway to a moving contact surface was investigated in detail. Head, center of mass, and center of pressure displacement were measured as the contact surface moved rhythmically at 0.1, 0.2, 0.4, 0.6, and 0.8 Hz. Stimulus amplitude decreased with frequency to maintain peak velocity constant across frequency. Head and body sway were highly coherent with contact surface motion at all frequencies except 0.8 Hz, where a drop-off in coherence was observed. Mean frequency of head and body sway matched the driving frequency ≤0.4 Hz. At higher frequencies, non-1:1 coupling was evident. The phase of body sway relative to the touch plate averaged 20–30° at 0.1-Hz drive and decreased approximately linearly to −130° at 0.8-Hz drive. System gain was ∼1 across frequency. The large phase lags observed cannot be accounted for with velocity coupling alone but indicate that body sway also was coupled to the position of the touch plate. Fitting of a linear second-order model to the data suggests that postural control parameters are not fixed but adapt to the moving frame of reference. Moreover, coupling to both position and velocity suggest that a spatial reference frame is defined by the somatosensory system.

scholarly journals Mental body rotation with egocentric and object-based transformations in different postures: standing vs. balancing

2021 ◽  
Vol 15 (3) ◽  
pp. 180-194
Author(s):  
Kirsten Budde ◽  
Thomas Jöllenbeck ◽  
José A. Barela ◽  
Gabriella A. Figueiredo ◽  
Matthias Weigelt
Keyword(s):  
Dynamic Stability ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Force Plate ◽  
Body Sway ◽  
Body Rotation ◽  
Balance Beam ◽  
Visual Spatial ◽  
Object Based ◽  
Effects Of Rotation

BACKGROUND: Previous studies suggest better visual-spatial processing when participants are tested in postures in which dynamic stability is challenged. The question arises if this is also true for the performance in mental body-rotation tasks (MBRT). AIM: Taking the embodied cognition approach into account, the first aim of the present study was to examine the potential influence of different demands on dynamic stability for two postures (parallel stand vs. tandem stand) on solving two versions of the MBRT, inducing either an object-based or an egocentric perspective transformation strategy. The second aim was to investigate if these different demands on dynamic stability are reflected in postural sway parameters. METHOD: Thirty participants (18 females and 12 males) were tested in the two MBRTs and in a control condition. All tasks were performed while standing on a balance beam in tandem stand and in a feet parallel position on a force plate. RESULTS: The results for response time and response error revealed effects of rotation angle and task, but no effect of posture. The analyzed Center of Pressure (CoP) data revealed a reduction of body sway during the MBRT for egocentric perspective transformations. CONCLUSION: The results indicate that participants performed better for egocentric than for object-based transformations and that the egocentric transformation leads to more postural stability than the object-based.

Influence of Textured Indoor Footwear on Posture Stability of Older Women Based on Center-of-Pressure Measurements

2019 ◽  
Vol 61 (8) ◽  
pp. 1247-1260 ◽  
Author(s):  
Pui-Ling Li ◽  
Kit-Lun Yick ◽  
Sun-Pui Ng ◽  
Joanne Yip
Keyword(s):  
Older Women ◽  
Plantar Pressure ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Balance Control ◽  
The Elderly ◽  
Textured Surface ◽  
Functional Impairments ◽  
Foot Pressure ◽  
Lateral Direction

Objective: The objective of this study is to evaluate the efficacy of indoor footwear with a textured surface to improve control of balance and reduce excessive plantar pressure in older women. Background: Balance instability is a common condition in older people. Textured insoles with protrusions on the entire insole have been examined for enhancing somatosensory feedback in the elderly to improve control over balance. However, these insoles have significant challenges in distributing the plantar pressure. Textured insoles with tailored protrusions should be therefore investigated for the same purpose but provide better plantar pressure distribution. Method: A total of 24 older women have undergone both static standing and walking tests with the use of the in-shoe Pedar® system. Results: The results indicate that wearing textured indoor footwear provides a significant reduction in postural sway, particularly in the medial–lateral direction during walking. As compared to walking barefoot, the center-of-pressure trajectory when wearing the textured indoor footwear remains supported with less variance among the steps, which is statistically significant in the medial–lateral direction. A significant reduction in the peak pressure is found in the forefoot and rearfoot regions as the plantar pressure is redistributed to the midfoot regions. Conclusion: The textured surface of the insole improves balance control of older women and effectively reduces foot pressure at high pressure areas. Application: The findings enhance current understanding on textured footwear as a form of intervention associated with changes in functional impairments, therefore providing basis for footwear design in balance control.

Changes of Postural Steadiness Following Use of Prefabricated Orthotic Insoles

2013 ◽  
Vol 29 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Hamid Bateni
Keyword(s):  
Fractal Dimension ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Postural Stabilization ◽  
The Mean ◽  
Velocity Changes ◽  
The Cost ◽  
Dominant Side ◽  
Orthotic Insoles ◽  
Postural Steadiness

Orthoses are designed to assist a malaligned foot in adapting to the environment and reduce the frequency of injury. Literature is divided on the benefits of orthotics insoles for postural stability. The current study was conducted to determine the effect of prefabricated orthotic arch supports on postural stabilization. Twelve healthy young adults participated in this study and were tested with and without prefabricated orthotics. Different variables were computed from movement of center of pressure (COP) during orthotic use as suggested in the literature. The mean position of COP was significantly shifted forward and toward the dominant side. Neither the COP movement nor the velocity changes following the use of orthotics revealed significant differences. Mediolateral range of COP movement and the 95% confidence circle area of sway was significantly reduced (P = .022 and 0.048 respectively), but changes in 95% confidence circle and ellipse areas of fractal dimension were not significant (P = .053 and P = .057 respectively). In conclusion, orthotic insoles significantly improved postural sway initially by reducing mediolateral range of postural sway and 95% confidence circle area of sway at the cost of increased fractal dimension area variables and power.

scholarly journals Cutaneous afferent innervation of the human foot sole: what can we learn from single-unit recordings?

2018 ◽  
Vol 120 (3) ◽  
pp. 1233-1246 ◽  
Author(s):  
Nicholas D. J. Strzalkowski ◽  
Ryan M. Peters ◽  
J. Timothy Inglis ◽  
Leah R. Bent
Keyword(s):  
Receptive Field ◽  
Single Unit ◽  
Body Position ◽  
Experimental Manipulation ◽  
The Body ◽  
Standing Balance ◽  
Cutaneous Afferents ◽  
Proprioceptive Information ◽  
Human Foot ◽  
Cutaneous Feedback

Cutaneous afferents convey exteroceptive information about the interaction of the body with the environment and proprioceptive information about body position and orientation. Four classes of low-threshold mechanoreceptor afferents innervate the foot sole and transmit feedback that facilitates the conscious and reflexive control of standing balance. Experimental manipulation of cutaneous feedback has been shown to alter the control of gait and standing balance. This has led to a growing interest in the design of intervention strategies that enhance cutaneous feedback and improve postural control. The advent of single-unit microneurography has allowed the firing and receptive field characteristics of foot sole cutaneous afferents to be investigated. In this review, we consolidate the available cutaneous afferent microneurographic recordings from the foot sole and provide an analysis of the firing threshold, and receptive field distribution and density of these cutaneous afferents. This work enhances the understanding of the foot sole as a sensory structure and provides a foundation for the continued development of sensory augmentation insoles and other tactile enhancement interventions.

scholarly journals The Association between the Center of Pressure and the Distribution of Foot Pressure during Forward-Backward Body Sway in Patients with Parkinson^|^rsquo;s Disease

2013 ◽  
Vol 28 (5) ◽  
pp. 601-606
Author(s):  
Mitsuhisa TODUKA ◽  
Hiroki MANI ◽  
Mamiko ARASAKI ◽  
Hiroyuki FUJITA ◽  
Tadao SUGATA ◽  
...  
Keyword(s):  
Center Of Pressure ◽  
Body Sway ◽  
Foot Pressure

scholarly journals Gender Differences in Postural Stability among 13-Year-Old Alpine Skiers

2020 ◽  
Vol 17 (11) ◽  
pp. 3859 ◽  
Author(s):  
Agnieszka D. Jastrzębska
Keyword(s):  
Gender Differences ◽  
Postural Balance ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Body Sway ◽  
Foot Pressure ◽  
Eyes Closed ◽  
Before And After ◽  
Eyes Open ◽  
Alpine Skiers

This experiment examined changes in body sway after Wingate test (WAnT) in 19 adolescents practicing alpine skiing, subjected to the same type of training load for 4–5 years (10 girls and nine boys). The postural examinations were performed with eyes open (EO), eyes closed (EC), and sway reverenced vision (SRV) in the medial-lateral (ML) and anterior-posterior (AP) planes. The displacement of center of foot pressure (CoP), range of sway (RS), mean sway velocity (MV), way length, and surface area were measured in bipedal upright stance before and after the WAnT to assess the influence of fatigue on postural balance. There were no significant differences in WAnT parameters between girls and boys. Relative peak power (RPP), relative total work (RWtot) were (girls vs. boys) 8.89 ± 0.70 vs. 9.57 ± 1.22 W/kg, p < 0.05 and 227.91 ± 14.98 vs. 243.22 ± 30.24 W/kg, p < 0.05 respectively. The fatigue index (FI) was also on similar level in both genders; however, blood lactate concentration (BLa) was significantly higher in boys (10.35 ± 1.16 mM) than in girls (8.67 ± 1.35 mM) p = 0.007. In the EO examination, statistically significant differences between resting and fatigue conditions in the whole group and after the division into girls and boys were found. In fatigue conditions, significant gender differences were noted for measurements in the ML plane (sway path and RS) and RS in the AP plane. Comparison of the three conditions shows differences between EO vs. EC and SRV in AP plane measured parameters, and for RS in ML plane in rest condition in girls. The strong correlations between FI and CoP parameters mainly in ML plane in the whole group for all examination conditions were noted. By genders, mainly RS in ML plane strongly correlates with FI (r > 0.7). No correlation was found between BLa and CoP parameters (p > 0.06). The presented results indicate that subjecting adolescents of both genders to the same training may reduce gender differences in the postural balance ability at rest but not in fatigue conditions and that girls are significantly superior in postural balance in the ML plane than boys. It was also shown that too little or too much information may be destructive to postural balance in young adolescents.

Sign in / Sign up

Export Citation Format

Share Document