Design and Biomechanical Evaluation Methodology of Pneumatic Ergonomic Crutch

Xiao, Chenzhang; Jahanian, Omid; Schnorenberg, Alyssa J.; Slavens, Brooke A.; Hsiao-Wecksler, Elizabeth T.

doi:10.1115/dmd2017-3512

Cited by 4 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Upon actuation (i.e., inflation), the FREE contracts and generates a tensile force in the longitudinal direction, thus providing constriction force about the forearm (Figure 3b). Such constriction force creates an interface between the forearm and the crutch that allows load sharing and restricts wrist extension/flexion during crutchassisted gait [21].…”

Section: Biomechanical Evaluation Of Pneumatic Sleeve Orthosis For Lo...mentioning

confidence: 99%

Biomechanical Evaluation of Pneumatic Sleeve Orthosis for Lofstrand Crutches

Xiao

Jahanian

Slavens

et al. 2023

IEEE Trans. Neural Syst. Rehabil. Eng.

View full text Add to dashboard Cite

Crutch walking, especially when using a swingthrough gait pattern, is associated with high, repetitive joint forces, hyperextension/ulnar deviation of the wrist, and excessive palmar pressure that compresses the median nerve. To reduce these adverse effects, we designed a pneumatic sleeve orthosis that utilized a soft pneumatic actuator and secured to the crutch cuff for long-term Lofstrand crutch users. Eleven able-bodied young adult participants performed both swing-through and reciprocal crutch gait patterns with and without the custom orthosis for comparison. Wrist kinematics, crutch forces, and palmar pressures were analyzed. Significantly different wrist kinematics, crutch kinetics, and palmar pressure distribution were observed in swing-through gait trials with orthosis use (p<0.001, p=0.01, p=0.03, respectively). Reductions in peak and mean wrist extension (7%, 6%), wrist range of motion (23%), and peak and mean ulnar deviation (26%, 32%) indicate improved wrist posture. Significantly increased peak and mean crutch cuff forces suggest increased load sharing between the forearm and cuff. Reduced peak and mean palmar pressures (8%, 11%) and shifted peak palmar pressure location toward the adductor pollicis denote a redirection of pressure away from the median nerve. In reciprocal gait trials, non-significant but similar trends were observed in wrist kinematics and palmar pressure distribution, whereas a significant effect of load sharing was noticed (p=0.01). These results suggest that Lofstrand crutches modified with orthosis may improve wrist posture, reduce wrist and palmar load, redirect palmar pressure away from the median nerve, and thus may reduce or prevent the onset of wrist injuries.

show abstract

Section: Biomechanical Evaluation Of Pneumatic Sleeve Orthosis For Lo...mentioning

confidence: 99%

Biomechanical Evaluation of Pneumatic Sleeve Orthosis for Lofstrand Crutches

Xiao

Jahanian

Slavens

et al. 2023

IEEE Trans. Neural Syst. Rehabil. Eng.

View full text Add to dashboard Cite

show abstract

“…To actuate the FREE, we have incorporated a pneumatic energy harvesting system into each crutch, which is composed of a crutch tip spring-loaded piston pump, a pneumatic elastomeric accumulator and a pneumatic circuit. More details of the system design can be found in [41]. In every crutch strike, the pump is compressed against the ground, charging the air into the FREE.…”

Section: Design and Evaluation Of Pneumatic Sleeve Orthosismentioning

confidence: 99%

Design and analysis of coiled fiber reinforced soft pneumatic actuator

et al. 2018

Self Cite

View full text Add to dashboard Cite

Fiber reinforced elastomeric enclosures (FREEs) are soft pneumatic actuators that can contract and generate forces upon pressurization. Typical engineering applications utilize FREEs in their straight cylindrical configuration and derive actuation displacement and forces from their ends. However, there are several instances in nature, such as an elephant trunk, snakes and grapevine tendrils, where a spiral configuration of muscle systems is used for gripping, thereby establishing a mechanical connection with uniform force distribution. Inspired by these examples, this paper investigates the constricting behavior of a contracting FREE actuator deployed in a spiral or coiled configuration around a cylindrical object. Force balance is used to model the blocked force of the FREE, which is then related to the constriction force using a string model. The modeling and experimental findings reveal an attenuation in the blocked force, and thus the constriction force caused by the coupling of peripheral contact forces acting in the spiral configuration. The usefulness of the coiled FREE configuration is demonstrated in a soft arm orthosis for crutch users that provides a constriction force around the forearm. This design minimizes injury risk by reducing wrist load and improving wrist posture.

show abstract

“…Li et al 29,[31][32][33] investigated effects of polyvinyl chloride gel soft actuator-based wearable assistive garments on hip joint support in walking. Singh and Xiao [34][35][36][37] designed a soft pneumatic interface between a crutch and user's forearm using a fiber-reinforced elastomeric enclosure to decrease wrist and palmer loads. However, these studies mainly focused on fabrication and experimental testing without theoretical models to demonstrate mechanical contacts between active garments and biological bodies.…”

Section: Introductionmentioning

confidence: 99%

Fluid–Structure Coupling Model and Experimental Validation of Interaction Between Pneumatic Soft Actuator and Lower Limb

et al. 2020

View full text Add to dashboard Cite

Pneumatic soft actuators (PSAs) are components that produce predesigned motion or force in different end-use devices. PSAs are lightweight, flexible, and compatible in human-machine interaction. The use of PSAs in compression therapy has proven promising in proactive pressure delivery with a wide range of dosages for treatment of chronic venous insufficiency and lymphedema. However, effective design and control of PSAs for dynamic pressure delivery have not been fully elaborated. The purpose of this study is to explore interactive working mechanisms between a PSA and lower limbs through establishing fluid-structure coupling models, an intermittent pneumatic compression (IPC) testing system, and conducting experimental validation. The developed IPC testing system consisted of a PSA unit (multichambered bladders laminated with an external textile shell), a pneumatic controller, and various real-time pressure monitoring sensors and accessory elements. The established coupling model characterized the dynamic response process with varying design parameters of the PSA unit, and demonstrated that the design of initial thickness, stiffness, and air mass flow of the PSA, as well as stiffness of limb tissues of the users, influenced PSA-lower limb interactions and resultant pressure dosages. The simulated results presented a favorable agreement with the experimental data collected by the IPC testing system. This study enhanced understanding of PSA-lower limb interactive working mechanisms and provided an evidence-based technical guidance for functional design of PSA. These results contribute to improving the efficacy of dynamic compression therapy for promotion of venous hemodynamics and user compliance in practice.

show abstract

Design and Biomechanical Evaluation Methodology of Pneumatic Ergonomic Crutch

Cited by 4 publications

References 0 publications

Biomechanical Evaluation of Pneumatic Sleeve Orthosis for Lofstrand Crutches

Biomechanical Evaluation of Pneumatic Sleeve Orthosis for Lofstrand Crutches

Design and analysis of coiled fiber reinforced soft pneumatic actuator

Fluid–Structure Coupling Model and Experimental Validation of Interaction Between Pneumatic Soft Actuator and Lower Limb

Contact Info

Product

Resources

About