Determination of Optimal Counter-Mass Location in Active Prostheses for Transfemoral Amputees to Replicate Sound Limb Swing

Recent advances in lower limb prostheses have involved the design of active, powered prosthetic knee and ankle-foot components capable of generating knee and ankle torques similar to that of normal gait. The associated componentry results in increased mass of the respective prosthesis, which affects the swing phase of gait. The goal of this study was to develop a computer model of the transfemoral residual limb and prosthesis, inclusive of an active ankle-foot, and investigate counter-mass magnitude(s) and location(s) via model optimization that might improve lower limb kinematic symmetry between the residual/prosthetic limb (approximated by the computer model) and the sound limb (approximated by able-bodied motion data) during swing phase. Single- (thigh only, shank only) and multisegment (both thigh and shank) optimization of counter-mass magnitudes and locations indicated that a 2.0 kg counter-mass added 8 cm distal and 10 cm posterior to the distal end of the knee unit within the shank segment approximated knee kinematics of the sound limb. This counter-mass location, however, reduced hip flexion during swing phase. While such a counter-mass location and magnitude demonstrated theoretical potential, the location is not clinically realistic; mass can only be practically added within the prosthesis, distal to the residual limb. Clinically, realistic counter-masses must also keep the total prosthetic mass to less than 5 kg; greater mass may require supplemental prosthetic suspension, may increase energy expenditure during ambulation and may increase the likelihood of fatigue, even with active prosthetic components. The ability to simulate the kinematic effects of active prosthetic components, inclusive of varying placement of battery and signal conditioning units, may advance the design of active prostheses that will minimize kinematic asymmetry and result in greater patient acceptance.

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Lower Limb Strength in Sports-Active Transtibial Amputees

Prosthetics and Orthotics International ◽

10.1080/03093640903082118 ◽

2009 ◽

Vol 33 (3) ◽

pp. 230-241 ◽

Cited By ~ 16

Author(s):

Lee Nolan

Keyword(s):

Residual Limb ◽

Hip Strength ◽

Prosthetic Limb ◽

Lower Limb Strength ◽

Flexion Extension ◽

Strength Asymmetry ◽

Lower Ratio ◽

Hip Flexion ◽

Transtibial Amputees ◽

Flexion And Extension

The aim of this study was to compare hip strength in sports-active transtibial (TT) amputees, sedentary TT amputees and sports-active non-amputees. Three ‘active’ (exercising recreationally at least three times per week) TT amputees, four ‘inactive’ or sedentary TT amputees and nine ‘active’ able-bodied persons (AB) underwent concentric and eccentric hip flexion and extension strength testing on both limbs on an isokinetic dynamometer at 60 and 120°/s. Little strength asymmetry was noted between the limbs of the active TT amputees (8% and 14% at 60 and 120°/s, respectively), their residual limb being slightly stronger. Inactive TT amputees demonstrated up to 49% strength asymmetry, their intact limb being the stronger. Active TT amputees demonstrated greater peak hip torques (Nm/kg) for all conditions and speeds compared to inactive TT amputees. Peak hip torques (Nm/kg), were greater in the active TT amputees' residual limb compared to AB. While inactive TT amputees and AB had similar flexion/extension ratios, active TT amputees exhibited a lower ratio indicating overdeveloped hip extensors with respect to their hip flexors. It is not known whether this is due to the demands of sport or exercise with a prosthetic limb, or remaining residual thigh atrophy.

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A comparison of the SACH and single axis foot in the gait of unilateral below-knee amputees

Prosthetics and Orthotics International ◽

10.3109/03093648309146713 ◽

1983 ◽

Vol 7 (1) ◽

pp. 33-36 ◽

Cited By ~ 29

Author(s):

N. E. Doane ◽

L. E. Holt

Keyword(s):

Lower Limb ◽

Gait Cycle ◽

Knee Prosthesis ◽

Statistical Significance ◽

Swing Phase ◽

Joint Angles ◽

Gait Patterns ◽

Prosthetic Devices ◽

Prosthetic Limb ◽

Points Of View

The gait patterns of unilateral below-knee amputees wearing prostheses with either a SACH foot or a single axis foot were compared. A temporary below-knee prosthesis was fabricated for each subject using plaster of Paris and Plastazote for the socket, a pylon and an artificial foot. Eight subjects were filmed at two separate sessions, one in which the SACH foot was worn on their prosthesis and one with the single axis foot on their prosthesis. Measurements of the normal leg with a SACH foot on the prosthetic limb were compared to measurements of the normal leg with a single axis foot on the prosthesis. Measurements of the prosthetic leg with both devices were also compared. A one tailed t test (p<.05) was used to determine statistical significance of the results obtained in six measurements of lower limb joint angles and on the percentage of the time of gait cycle for stance and swing phase of the prosthetic leg. Discussion centres on the interpretation of the results from both statistical and clinical points of view. Major differences (excepting the ankle at foot-flat) between the prosthetic devices were not found.

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Poster 151 differential impact of lower-limb strength and coordination on gait swing phase restoration after 7 years of persistent gait deficits: an intervention case study. Sandhya R. Meesala, MD (Cleveland VA Med Ctr, Cleveland, Oh); Janis J. Daly, PhD, MS, e-mail: [email protected]

Archives of Physical Medicine and Rehabilitation ◽

10.1016/j.apmr.2004.07.219 ◽

2004 ◽

Vol 85 (9) ◽

pp. e35

Keyword(s):

Lower Limb ◽

Swing Phase ◽

Differential Impact ◽

Lower Limb Strength ◽

E Mail

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Toward improving residual limb climate within prostheses for persons with lower limb loss

Prosthetics and Orthotics International ◽

10.1097/pxr.0000000000000085 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Ashley D Knight ◽

Brad D Hendershot ◽

Todd J Sleeman ◽

Christopher L Dearth ◽

Felix Starker ◽

...

Keyword(s):

Lower Limb ◽

Limb Loss ◽

Residual Limb

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Obesity and Skin Problems in Persons With a Lower Limb Amputation: An Observational Study

10.21203/rs.3.rs-332506/v1 ◽

2021 ◽

Author(s):

Terezka S. Mollee ◽

Pieter U. Dijkstra ◽

Rienk Dekker ◽

Jan H.B. Geertzen

Keyword(s):

Body Mass Index ◽

Body Weight ◽

Confidence Interval ◽

Body Mass ◽

Lower Limb ◽

Lower Limb Amputation ◽

Limb Amputation ◽

Residual Limb ◽

Prevalence Of Obesity ◽

The Impact

Abstract Background: A lower limb amputation can lead to weight gain and obesity. However, data regarding the prevalence of obesity in the Dutch population with a lower limb amputation are lacking. Furthermore, the impact of obesity on skin problems of the residual limb and the need of prosthetic repairs is unknown. The aim of this study was to determine the prevalence of obesity in Dutch persons with a lower limb amputation and to investigate the relationship between body weight, body mass index and skin problems of the residual limb and the frequency of prosthetic repairs. Methods: A survey was performed among adults with a unilateral lower limb amputation due to any cause, and who are user of a prosthesis. The survey consisted of measurement of the subjects’ body height and weight, a questionnaire which assessed self-reported skin problems in the previous month and factors potentially associated with these skin problems, and assessment of the frequency of visits to the orthopedic workshop. Results: In total, 413 persons were enrolled. Of them, 39% (95% confidence interval 35%−44%) was overweight and 28% (95% confidence interval 24%−33%) was obese. A total of 77% (95% confidence interval 73%−81%) reported one or more skin problems in the past month. Body weight and body mass index were neither associated with the presence of skin problems in general nor with the number of prosthetic repairs. Persons with severe skin problems had a slightly lower body mass index (26.6 kg/m2 vs. 28.0 kg/m2, p = 0.012). Persons with skin problems were younger than those without (difference in means 6.0 years (95% confidence interval 3.0−8.9)). Conclusion: Our findings show that obesity is common in the ambulant population with a lower limb amputation, with a prevalence being higher than in the general Dutch adult population. However, its negative impact on the presence of skin problems and the frequency of prosthetic repairs may be limited.

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The functional use of the reciprocal hip mechanism during gait for paraplegic patients walking in the Louisiana State University reciprocating gait orthosis

Prosthetics and Orthotics International ◽

10.3109/03093649909071627 ◽

1999 ◽

Vol 23 (2) ◽

pp. 152-162 ◽

Cited By ~ 23

Author(s):

P. M. Dall ◽

B. Müller ◽

I. Stallard ◽

J. Edwards ◽

M. H. Granat

Keyword(s):

Hip Joint ◽

Swing Phase ◽

Spinal Injuries ◽

Small Contribution ◽

State University ◽

Hip Joints ◽

Cable Tension ◽

Louisiana State University ◽

Hip Flexion ◽

Limb Flexion

Reciprocally linked orthoses used for paraplegic walking have some form of linkage between the two hip joints. It has been assumed that flexion of the swinging leg is driven by extension of the stance leg. The aims of this study were to investigate the moments generated around the hip joint by the two cables in a Louisiana State University Reciprocating Gait Orthosis (LSU-RGO). Six (6) subjects were recruited from the Regional Spinal Injuries Centre at Southport, who were experienced RGO users. The cables were fitted with strain gauged transducers to measure cable tension. Foot switches were used to divide the gait into swing and stance phases. A minimum of 20 steps were analysed for each subject. Moments about the hip joint for each phase of gait were calculated. There were no moments generated by the front cable in 4 of the subjects. In only 2 subjects did the cable generate a moment that could assist hip flexion during the swing phase. These moments were very low and at best could only have made a small contribution to limb flexion. The back cable generated moments that clearly prevented bilateral flexion. It was concluded that the front cable, as used by these experienced RGO users, did not aid flexion of the swinging limb.

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The reference research of exercise therapy of residual limb in post-operative of lower limb amputation

7th Asian-Pacific Conference on Medical and Biological Engineering - IFMBE Proceedings ◽

10.1007/978-3-540-79039-6_120 ◽

2008 ◽

pp. 480-483

Author(s):

Xiaoyu Zhang ◽

Qidong Liu ◽

Chunjing Tao ◽

Huiru Gu

Keyword(s):

Exercise Therapy ◽

Lower Limb ◽

Lower Limb Amputation ◽

Limb Amputation ◽

Residual Limb

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Investigating the Effect of Real-Time Center of Pressure (CoP) Feedback Training on the Swing Phase of Lower Limb Kinematics in Transfemoral Prostheses with SACH foot

Journal of Biomechanical Engineering ◽

10.1115/1.4053364 ◽

2021 ◽

Author(s):

Ashutosh Tiwari ◽

Abhijeet Kujur ◽

Jyoti Kumar ◽

Deepak Joshi

Keyword(s):

Real Time ◽

Lower Limb ◽

Knee Flexion ◽

Center Of Pressure ◽

Feedback System ◽

Swing Phase ◽

Flexion Angle ◽

Heel Strike ◽

Knee Flexion Angle ◽

Joint Angles

Abstract Transfemoral amputee often encounters reduced toe clearance resulting in trip-related falls. Swing phase joint angles have been shown to influence the toe clearance therefore, training intervention that targets shaping the swing phase joint angles can potentially enhance toe clearance. The focus of this study was to investigate the effect of the shift in the location of the center of pressure (CoP) during heel strike on modulation of the swing phase joint angles in able-bodied participants (n=6) and transfemoral amputees (n=3). We first developed a real-time CoP-based visual feedback system such that participants could shift the CoP during treadmill walking. Next, the kinematic data were collected during two different walking sessions- baseline (without feedback) and feedback (shifting the CoP anteriorly/posteriorly at heel strike to match the target CoP location). Primary swing phase joint angle adaptations were observed with feedback such that during the mid-swing phase, posterior CoP shift feedback significantly increases (p<0.05) the average hip and knee flexion angle by 11.55 degrees and 11.86 degrees respectively in amputees, whereas a significant increase (p<0.05) in ankle dorsiflexion, hip and knee flexion angle by 3.60 degrees, 3.22 degrees, and 1.27 degrees respectively compared to baseline was observed in able-bodied participants. Moreover, an opposite kinematic adaptation was seen during anterior CoP shift feedback. Overall, results confirm a direct correlation between the CoP shift and the modulation in the swing phase lower limb joint angles.

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