0
Research Papers

A Coronally Clutching Ankle to Improve Amputee Balance on Coronally Uneven and Unpredictable Terrain

[+] Author and Article Information
Kyle H. Yeates

Department of Mechanical Engineering,
University of Washington,
Seattle, WA 98195;
Department of Veterans Affairs,
Center for Limb Loss and Mobility,
1660 S. Columbian Way MS-151,
Seattle, WA 98108
e-mail: kyle.yeates@gmail.com

Ava D. Segal

Department of Veterans Affairs,
Center for Limb Loss and Mobility,
1660 S. Columbian Way MS-151,
Seattle, WA 98108
e-mail: avasegal@gmail.com

Richard R. Neptune

Department of Mechanical Engineering,
The University of Texas at Austin,
Austin, TX 78712
e-mail: rneptune@mail.utexas.edu

Glenn K. Klute

Department of Mechanical Engineering,
University of Washington,
Seattle, WA 98195;
Department of Veterans Affairs,
Center for Limb Loss and Mobility,
1660 S. Columbian Way MS-151,
Seattle, WA 98108
e-mail: gklute@u.washington.edu

Manuscript received January 18, 2017; final manuscript received April 11, 2018; published online July 13, 2018. Assoc. Editor: Elizabeth Hsiao-Wecksler.

J. Med. Devices 12(3), 031001 (Jul 13, 2018) (12 pages) Paper No: MED-17-1011; doi: 10.1115/1.4040183 History: Received January 18, 2017; Revised April 11, 2018

To improve the balance of individuals with lower limb amputation on coronally uneven terrain, a coronally clutching ankle (CCA) was developed to actively adapt through ±15 deg of free coronal foot rotation during the first ∼60 ms of initial contact. Three individuals with lower limb amputations were fit with the CCA and walked across an instrumented walkway with a middle step that was either flush, 15 deg inverted, or 15 deg everted. An opaque latex membrane was placed over the middle step, making the coronally uneven terrain unpredictable. Compared to participants' clinically prescribed prosthesis, the CCA exhibited significantly more coronal angular adaption during early stance. The CCA also improved participants' center of mass (COM) path regulation during the recovery step (reduced variation in mediolateral position) and reduced the use of the hip and stepping recovery strategies, suggesting it improved participants' balance and enabled a quicker recovery from the disturbance. However, use of the CCA did not significantly affect participants' ability to regulate their coronal angular momentum during the disturbance, suggesting that the CCA did not improve all elements of dynamic balance. Reducing the distance between the CCA's pivot axis and the base of the prosthetic foot might resolve this issue. These findings suggest that actively adapting the coronal plane angle of a prosthetic ankle can improve certain elements of balance for individuals with lower limb amputation who walk on coronally uneven and unpredictable terrain.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Li, W. , Keegan, T. H. M. , Sternfeld, B. , Sidney, S. , Quesenberry, C. P. , and Kelsey, J. L. , 2006, “ Outdoor Falls Among Middle-Aged and Older Adults: A Neglected Public Health Problem,” Am. J. Public Health, 96(7), pp. 1192–1200. [CrossRef] [PubMed]
Silverman, A. K. , and Neptune, R. R. , 2011, “ Differences in Whole-Body Angular Momentum Between Below-Knee Amputees and Non-Amputees Across Walking Speeds,” J. Biomech., 44(3), pp. 379–385. [CrossRef] [PubMed]
Neptune, R. R. , and McGowan, C. P. , 2011, “ Muscle Contributions to Whole-Body Sagittal Plane Angular Momentum During Walking,” J. Biomech., 44(1), pp. 6–12. [CrossRef] [PubMed]
Neptune, R. R. , and McGowan, C. P. , 2016, “ Muscle Contributions to Frontal Plane Angular Momentum During Walking,” J. Biomech., 49(13), pp. 2975–2981. [CrossRef] [PubMed]
Yeates, K. H. , Segal, A. D. , Neptune, R. R. , and Klute, G. K. , 2016, “ Balance and Recovery on Coronally-Uneven and Unpredictable Terrain,” J. Biomech., 49(13), pp. 2734–2740. [CrossRef] [PubMed]
Segal, A. , and Klute, G. , 2014, “ Lower-Limb Amputee Recovery Response to an Imposed Error in Mediolateral Foot Placement,” J. Biomech., 47(12), pp. 2911–2918. [CrossRef] [PubMed]
LaPre, A. K. , and Sup, F. , 2011, “ Simulation of a Slope Adapting Ankle Prosthesis Provided by Semi-Active Damping,” Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Boston, MA, Aug. 30–Sept. 3, pp. 587–590.
Williams, R. J. , Hansen, A. H. , and Gard, S. A. , 2009, “ Prosthetic Ankle-Foot Mechanism Capable of Automatic Adaptation to the Walking Surface,” ASME J. Biomech. Eng., 131(3), p. 035002. [CrossRef]
MacKinnon, C. D. , and Winter, D. A. , 1993, “ Control of Whole Body Balance in the Frontal Plane During Human Walking,” J. Biomech., 26(6), pp. 633–644. [CrossRef] [PubMed]
Herr, H. , and Popovic, M. , 2008, “ Angular Momentum in Human Walking,” J. Exp. Biol., 211(4), pp. 467–481. [CrossRef] [PubMed]
Allum, J. H. J. , Adkin, A. L. , Carpenter, M. G. , Held-Ziolkowska, M. , Honegger, F. , and Pierchala, K. , 2001, “ Trunk Sway Measures of Postural Stability During Clinical Balance Tests: Effects of a Unilateral Vestibular Deficit,” Gait Posture, 14(3), pp. 227–237. [CrossRef] [PubMed]
Hof, A. L. , van Bockel, R. M. , Schoppen, T. , and Postema, K. , 2007, “ Control of Lateral Balance in Walking: Experimental Findings in Normal Subjects and above-Knee Amputees,” Gait Posture, 25(2), pp. 250–258. [CrossRef] [PubMed]
Marigold, D. S. , and Patla, A. E. , 2002, “ Strategies for Dynamic Stability During Locomotion on a Slippery Surface: Effects of Prior Experience and Knowledge,” J. Neurophysiol., 88(1), pp. 339–353. [CrossRef] [PubMed]
Gorges, J. J. , 2013, “ Controlled Coronal Stiffness Prosthetic Ankle for Improving Balance on Uneven Terrain,” Master's thesis, University of Washington, Seattle, WA. https://digital.lib.washington.edu/researchworks/handle/1773/24166
Ferrari, A. , Benedetti, M. G. , Pavan, E. , Frigo, C. , Bettinelli, D. , Rabuffetti, M. , Crenna, P. , and Leardini, A. , 2008, “ Quantitative Comparison of Five Current Protocols in Gait Analysis,” Gait Posture, 28(2), pp. 207–216. [CrossRef] [PubMed]
Kobayashi, T. , Orendurff, M. S. , Arabian, A. K. , Rosenbaum-Chou, T. G. , and Boone, D. A. , 2014, “ Effect of Prosthetic Alignment Changes on Socket Reaction Moment Impulse During Walking in Transtibial Amputees,” J. Biomech., 47(6), pp. 1315–1323. [CrossRef] [PubMed]
Federal Highway Administration, 1999, “ Chapter 4—Sidewalk Design Guidelines and Existing Practices,” U.S. Department of Transportation, Washington, DC, accessed Feb. 9, 2016, http://www.fhwa.dot.gov/environment/bicycle_pedestrian/publications/sidewalks/chap4b.cfm
Sawers, A. , and Hahn, M. E. , 2013, “ Gradual Training Reduces Practice Difficulty While Preserving Motor Learning of a Novel Locomotor Task,” Hum. Mov. Sci., 32(4), pp. 605–617. [CrossRef] [PubMed]

Figures

Grahic Jump Location
Fig. 1

Mean coronal foot angle with respect to the tibia of ten nonamputees walking on coronally uneven and unpredictable terrain [5]. Conditions shown for unblinded flush, blinded 15 deg inversion, and blinded 15 deg eversion terrain conditions. The point at which participants reached 90% of their maximum angular displacement for a given condition, and early stance, is shown for all conditions. Positive values associated with ankle inversion.

Grahic Jump Location
Fig. 2

(a) Expanded view of CCA with all major components grouped into the proximal section (top) and distal section (bottom). (b) Rear isometric views of CCA demonstrating the ±15 deg limit of foot-mount rotation. Note that only the foot-mount rotation was controlled by the CCA, and that elastic deformation within the prosthetic foot keel could create additional foot rotation.

Grahic Jump Location
Fig. 3

Exploded view of the clutch in CCA device

Grahic Jump Location
Fig. 4

(a) Cross section through the clutch in the free state showing how rotation of the servo cam translated the pawl release arm upward, disengaging the pawls and allowing the ratchet gear to spin freely, (b) cross section through the clutch in the locked state showing how rotation of the cam allowed the pawl release arm to move downward, allowing the spring-loaded pawls to engage the ratchet gear, ceasing its rotation, and (c) manufactured internal components of clutch

Grahic Jump Location
Fig. 5

(a) Walkway with embedded force plates, handrails, and signal light (blue trapezoid) for communication with CCA. The experimental setup is shown in the blinded condition, in which the disturbance device was concealed beneath a latex membrane (outlined by red dashed line). (b)–(d) Posterior view of a left amputee participant with CCA stepping on the disturbance device in the everted (b), flush (c), and inverted (d) positions. The experimental setup is shown without the latex membrane installed, and the portable force plate is highlighted with a red line.

Grahic Jump Location
Fig. 6

Anterior view of bench testing for an inversion trial with a left foot. CCA with electronics shown mounted to the head of tester, with the sliding test base beneath.

Grahic Jump Location
Fig. 7

Load frame test results for a 1000 N load with a feed rate of 50 mm/s. Time shown relative to HS detection. (a) Mean clutch spool angle in degrees for inversion and eversion. (b) Mean foot-mount angle in degrees for both inversion and eversion. ±SD symbolizes the corresponding data set's standard deviation is displayed in the figure.

Grahic Jump Location
Fig. 8

Top down view of lab coordinate system displaying participants' mean COM path from intact limb lead-in step HS to intact limb recovery step toe off shown for (a) adapting CCA, (b) locked CCA, and (c) as-prescribed prosthesis conditions. COM location at HS of the three steps, as well as at midstance of the recovery step are marked. AJC location at HSs are also marked. All locations zeroed to lead-in step HS COM position, and left-amputee mediolateral data negated to match right-amputee participants.

Grahic Jump Location
Fig. 9

Mean foot coronal angle with respect to the pylon (proximal portion of CCA) for all terrain and prosthesis combinations during the disturbed stance. For the CCA in adapting condition, position of the foot-mount with respect to the proximal portion of the CCA is also shown. A 90% rise time of foot angle on uneven terrain and an early stance for all conditions are shown for reference. Positive values associated with ankle inversion. ±SD symbolizes the corresponding data set's standard deviation is displayed in the figure.

Grahic Jump Location
Fig. 10

Mean coronal moment about CCA pivot (or equivalent point for the as-prescribed prosthesis) over the disturbed stance for all prosthesis and terrain combinations. The 90% foot angle rise times for uneven terrain conditions are shown for reference. Positive values associated with ankle invertor moment. ±SD symbolizes the corresponding data set's standard deviation is displayed in the figure.

Grahic Jump Location
Fig. 11

Mean coronal angular momentum for all terrain and prosthesis combinations during the disturbed gait period. HS1 and HS2 signify HS of disturbed and recovery steps, respectively. Positive values associated with positive rotation about the participants' sagittal axis (originating from body and pointing anteriorly) [5]. ±SD symbolizes the corresponding data set's standard deviation is displayed in the figure.

Grahic Jump Location
Fig. 12

Mean coronal hip moment over the disturbed stance for all prosthesis and terrain combinations. The 90% foot angle rise times for uneven terrain conditions are shown for reference. Positive values associated with hip adductor moment. ±SD symbolizes the corresponding data set's standard deviation is displayed in the figure.

Grahic Jump Location
Fig. 13

Posterior view of the CCA, with the center of pressure and GRF during steps on inverted (a) and (c) and everted (b) and (d) terrain with the CCA in adapting (a) and (b) and locked (c) and (d) modes. All forces and locations are oriented relative to the proximal segment of the CCA. Images represent mean data from all participants at early stance. Data normalized to right side amputees, lateral and superior values are positive. Base of support limits are equivalent to the medial and lateral limits of the shoe.

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In