Techniques to measure rigidity of ankle-foot orthosis: a review.

We performed this review to provide a clearer understanding of how to effectively measure ankle-foot orthosis (AFO) rigidity. This information is important to ensure appropriate orthotic intervention in the treatment of patients with pathological gait. The two main approaches to the investigation of AFO rigidity are (1) bench-testing analyses, in which an AFO is fixed or attached to a measurement device, and (2) functional analyses, in which measurements are taken while a subject is walking with an AFO in situ. This review summarizes and classifies the current state of knowledge of AFO rigidity testing methods. We analyzed the strengths and weaknesses of the methods in order to recommend the most reliable techniques to measure AFO rigidity. The information obtained from this review article would, therefore, benefit both clinicians and engineers involved in the application and design of AFOs.

[1]  Joseph M. Mansour,et al.  Design Changes in Ankle-Foot Orthosis Intended to Alter Stiffness Also Alter Orthosis Kinematics , 1999 .

[2]  Stefania Fatone,et al.  Effect of ankle-foot orthosis alignment and foot-plate length on the gait of adults with poststroke hemiplegia. , 2009, Archives of physical medicine and rehabilitation.

[3]  K. Kaufman,et al.  Stiffness of the Arizona Ankle-Foot Orthosis Before and After Modification for Gait Analysis , 2009 .

[4]  P. Convery,et al.  Test apparatus for the measurement of the flexibility of ankle-foot orthoses in planes other than the loaded plane , 1998, Prosthetics and orthotics international.

[5]  Y Suzuki,et al.  Stiffness control in posterior-type plastic ankle-foot orthoses: Effect of ankle trimline Part 2: Orthosis characteristics and orthosis/patient matching , 1996, Prosthetics and orthotics international.

[6]  R. Major,et al.  A new structural concept in moulded fixed ankle foot orthoses and comparison of the bending stiffness of four constructions , 2004, Prosthetics and orthotics international.

[7]  Dynamic strain analysis of below-knee orthopedic braces. A preliminary report. , 1968, American journal of physical medicine.

[8]  Elaine Owen,et al.  The Importance of Being Earnest about Shank and Thigh Kinematics Especially When Using Ankle-Foot Orthoses , 2010, Prosthetics and orthotics international.

[9]  Sumiko Yamamoto,et al.  Comparative Study of Mechanical Characteristics of Plastic AFOs , 1993 .

[10]  P Cappa,et al.  A novel device to evaluate the stiffness of ankle-foot orthosis devices. , 2003, Journal of biomechanical engineering.

[11]  D. Condie,et al.  Ankle Foot Orthoses , 1991, JPO Journal of Prosthetics and Orthotics.

[12]  Daan J J Bregman,et al.  Studies Examining the Efficacy of Ankle Foot Orthoses should Report Activity Level and Mechanical Evidence , 2010, Prosthetics and orthotics international.

[13]  Steve West,et al.  Biomechanical basis of orthotic management , 1995 .

[14]  A system for the continuous measurement of ankle joint moment in hemiplegic patients wearing ankle-foot orthoses. , 1993, Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering.

[15]  S. Yamamoto,et al.  Development of an ankle – foot orthosis with an oil damper , 2005, Prosthetics and orthotics international.

[16]  P. Bowker,et al.  Biomechanical basis of orthotic management , 1993 .

[17]  Development of a Testing Apparatus for Structural Stiffness Evaluation of Ankle-Foot Orthoses , 2001 .

[18]  Comparison of bending stiffness of six different colours of copolymer polypropylene , 1999, Prosthetics and orthotics international.

[19]  Toshiki Kobayashi,et al.  Design of an Automated Device to Measure Sagittal Plane Stiffness of an Articulated Ankle-Foot Orthosis , 2010, Prosthetics and orthotics international.

[20]  H. Houdijk,et al.  Polypropylene Ankle Foot Orthoses to Overcome Drop-Foot Gait in Central Neurological Patients: A Mechanical and Functional Evaluation , 2010, Prosthetics and orthotics international.

[22]  S. Miyazaki,et al.  Effect of ankle-foot orthosis on active ankle moment in patients with hemiparesis , 1997, Medical and Biological Engineering and Computing.

[23]  G. C. Robin,et al.  Dynamic stress analysis of below-knee drop foot braces , 2006, Medical and biological engineering.

[24]  Yasushi Akazawa,et al.  Quantitative measurement of spastic ankle joint stiffness using a manual device: a preliminary study. , 2010, Journal of biomechanics.

[25]  J Harlaar,et al.  A new method for evaluating ankle foot orthosis characteristics: BRUCE. , 2009, Gait & posture.

[26]  Y Suzuki,et al.  Stiffness control in posterior-type plastic ankle-foot orthoses: Effect of ankle trimline Part 1: A device for measuring ankle moment , 1996, Prosthetics and orthotics international.

[27]  G. C. Robin,et al.  Dynamic analysis of plastic below-knee drop foot braces , 2006, Medical and biological engineering.

[28]  M Nagaya,et al.  Shoehorn-type ankle-foot orthoses: prediction of flexibility. , 1997, Archives of physical medicine and rehabilitation.

[29]  S. Miyazaki,et al.  Quantification of the Effect of Dorsi-/ Plantarflexibility of Ankle-Foot Orthoses on Hemiplegic Gait: A Preliminary Report , 1993 .

[30]  The modern ankle-foot orthoses (AFO's). , 1973, Bulletin of prosthetics research.

[31]  Sumiko Yamamoto,et al.  Development of an Ankle-Foot Orthosis with Dorsiflexion Assist, Part 2 , 1999 .

[32]  Adam Rozumalski,et al.  Quantifying the Spring-Like Properties of Ankle-Foot Orthoses (AFOs) , 2007 .

[33]  Thomas R. Lunsford,et al.  Viscoelastic Properties of Plastic Pediatric AFOs , 1994 .

[34]  Thomas R. Lunsford,et al.  The Effect of Malleolar Prominence on Polypropylene AFO Rigidity and Buckling , 1989 .

[35]  Dynamic stress analysis of below-knee drop foot braces; Studies on patients with paralysis of the lower limb , 1969, Medical and biological engineering.

[36]  T. Takeuchi,et al.  A new model of plastic ankle foot orthosis (FAFO (II)) against spastic foot and genu recurvatum , 1992, Prosthetics and orthotics international.

[37]  Plantarflexion Resistance of Selected Ankle-Foot Orthoses: A Pilot Study of Commonly Prescribed Prefabricated and Custom-Molded Alternatives , 2001 .

[38]  Sumiko Yamamoto,et al.  Quantification of the effect of the mechanical property of ankle-foot orthoses on hemiplegic gait , 1993 .

[39]  Sumiko Yamamoto,et al.  Development of a New Ankle-Foot Orthosis with Dorsiflexion Assist, Part 1: Desirable Characteristics of Ankle-Foot Orthoses for Hemiplegic Patients , 1997 .

[40]  Determination of Stress Distribution In Various Ankle-Foot Orthoses: Experimental Stress Analysis , 1998 .

[41]  P. Cappa,et al.  A continuous loading apparatus for measuring three-dimensional stiffness of ankle-foot orthoses. , 2005, Journal of biomechanical engineering.