Jeffery W Rankin

Jeffery W Rankin
Rancho Research Institute | RRI · Pathokinesiology Laboratory

Ph.D, Mechanical Engineering

About

95
Publications
11,727
Reads
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647
Citations
Additional affiliations
January 2018 - present
Rancho Los Amigos Rehabilitation Center
Position
  • Managing Director
January 2018 - present
Rancho Los Amigos Rehabilitation Center
Position
  • Managing Director
August 2016 - December 2017
University of Idaho
Position
  • Research Associate

Publications

Publications (95)
Article
Objective: Shoulder pain after spinal cord injury (SCI) is attributed to increased mobility demands on the arms and negatively impacts independence and quality of life. Repetitive superior and posterior shoulder joint forces produced during traditional wheelchair (WC) locomotion can result in subacromial impingement if unopposed, as with muscular f...
Article
Full-text available
Mechanically, the most economical gait for slow bipedal locomotion requires walking as an 'inverted pendulum', with: I, an impulsive, energy-dissipating leg compression at the beginning of stance; II, a stiff-limbed vault; and III, an impulsive, powering push-off at the end of stance. The characteristic 'M'-shaped vertical ground reaction forces of...
Article
Full-text available
Owing to their cursorial background, ostriches (Struthio camelus) walk and run with high metabolic economy, can reach very fast running speeds and quickly execute cutting manoeuvres. These capabilities are believed to be a result of their ability to coordinate muscles to take advantage of specialized passive limb structures. This study aimed to inf...
Article
Full-text available
Locomotor control mechanisms must flexibly adapt to both anticipated and unexpected terrain changes to maintain movement and avoid a fall. Recent studies revealed that ground birds alter movement in advance of overground obstacles, but not treadmill obstacles, suggesting context-dependent shifts in use of anticipatory control. We hypothesized that...
Article
Serially connected robots are promising candidates for performing tasks in confined spaces such as search and rescue in large-scale disasters. Such robots are typically limbless, and we hypothesize that the addition of limbs could improve mobility. However, a challenge in designing and controlling such devices lies in the coordination of high-dimen...
Article
Many animals generate propulsive forces by coordinating legs, which contact and push against the surroundings, with bending of the body, which can only indirectly influence these forces. Such body–leg coordination is not commonly employed in quadrupedal robotic systems. To elucidate the role of back bending during quadrupedal locomotion, we study a...
Article
Up to 84% of manual wheelchair users (MWCUs) with spinal cord injury experience shoulder pain, which is correlated with shoulder adductor weakness in this population. Modeling studies have shown weak shoulder adductors lead to compensations from the deltoid and rotator cuff muscles during propulsion, which may lead to altered propulsion mechanics....
Article
Full-text available
Standing up from a prone position is a critical daily activity for animals: failing to do so effectively may cause an injurious fall or increase predation susceptibility. This sit-to-stand behaviour (StS) is biomechanically interesting because it necessitates transitioning through near-maximal joint motion ranges from a crouched (i.e., poor mechani...
Article
Full-text available
Flapping flight is the most power-demanding mode of locomotion, associated with a suite of anatomical specializations in extant adult birds. In contrast, many developing birds use their forelimbs to negotiate environments long before acquiring “flight adaptations,” recruiting their developing wings to continuously enhance leg performance and, in so...
Article
Many cursorial and large hopping species are extremely efficient locomotors with various morphological adaptations believed to reduce mechanical demand and improve movement efficiency, including elongated distal limb segments. However, despite having elongated limbs, small hoppers such as desert kangaroo rats (Dipodomys deserti) are less efficient...
Preprint
Full-text available
Many quadrupedal animals have lateral degrees of freedom in their backs that assist locomotion. This paper seeks to use a robotic model to demonstrate that back bending assists not only forward motion, but also lateral and turning motions. This paper uses geometric mechanics to prescribe gaits that coordinate both leg movements and back bending mot...
Conference Paper
Full-text available
This study probes the underlying locomotion principles of earliest organisms that could both swim and walk. We hypothesize that properly coordinated leg and body movements could have provided a substantial benefit toward locomotion on complex media, such as early crawling on sand. In this extended abstract, we summarize some of our recent advances...
Article
Full-text available
Horse racing is a multi-billion-dollar industry that has raised welfare concerns due to injured and euthanized animals. Whilst the cause of musculoskeletal injuries that lead to horse morbidity and mortality is multifactorial, pre-existing pathologies, increased speeds and substrate of the racecourse are likely contributors to foot disease. Horse h...
Data
Maximum principal stress (MPa) distribution results for the shod and the unshod horse foot, in dorsal view Bones shown from top to bottom are the P1, P2 and P3. Warm (red) and cold (blue) colours show higher and lower maximum principal stresses respectively.
Data
Ground reaction force (GRF) data in Newtons for the unshod (n = 4) and shod (n = 4) conditions
Data
Minimum principal stress (MPa) distribution results for the shod and the unshod horse foot, in dorsal view Bones shown from top to bottom are the P1, P2 and P3. Warm (red) and cold (blue) colours show higher and lower minimum principal stresses respectively.
Data
Sensitivity analysis on the P1 constraints BC1 constraints are applied on the entire distal joint surface of the P1 and fixed in all axes. BC2 constraints involve fix constraining 3 nodes at the distal joint surface on the centroid axis of the load. The remainder nodes are fixed on the long axis of the bone only. Transparent and non-transparent ima...
Data
Sensitivity analysis on the location of the P3 constraints and the respective von Mises stresses patterns on the palmar and dorsal views Warm (red) and cold (blue) colours show higher and lower von Mises stresses respectively.
Data
Raw speed data for the unshod (n = 4) and shod (n = 4) conditions Column A shows the conditions. Column B lists the name and date of the steps. Column C lists the horse’s hip height in meters. Column D lists the frame rate of the Sony camera used for the speed calculations. Columns E and F list the start and end frame of each trial and each conditi...
Data
The position of the custom-designed calibration cube used during the fluoroscopy experiments to calibrate the 3D space in the XROMM analysis
Data
Loading (in red) and boundary (in orange) locations for the P1, P2 and P3 bones (see Methods: Loads and constraints)
Data
Maximum principal stress (MPa) distribution results for the shod and the unshod horse foot, in palmar view Bones shown from top to bottom are the P1, P2 and P3. Warm (red) and cold (blue) colours show higher and lower maximum principal stresses respectively.
Data
Minimum principal stress (MPa) distribution results for the shod and the unshod horse foot, in palmar view Bones shown from top to bottom are the P1, P2 and P3. Warm (red) and cold (blue) colours show higher and lower minimum principal stresses respectively.
Data
Degrees of motion for proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints for the shod (n = 4) and unshod (n = 4) conditions about the flexion-extension axis
Article
Full-text available
Horse racing is a multi-billion-dollar industry that has raised welfare concerns due to disabled and euthanized animals. Whilst the cause of musculoskeletal injuries that lead to horse morbidity and mortality is multifactorial, pre-existing pathologies, increased speeds and substrate of the racecourse are likely contributors to foot disease. The ho...
Article
Full-text available
Horse racing is a multi-billion-dollar industry that has raised welfare concerns due to disabled and euthanized animals. Whilst the cause of musculoskeletal injuries that lead to horse morbidity and mortality is multifactorial, pre-existing pathologies, increased speeds and substrate of the racecourse are likely contributors to foot disease. The ho...
Article
Full-text available
We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model...
Conference Paper
Full-text available
Foot anatomy and mechanics vary among herbivorous quadrupeds. Horses have one toe ending in a rigid hoof, which is effective for fast-running but generates large impact vibrations. The feet of the elephants and rhinoceroses have five and three toes, respectively, bound within a digital cushion, which absorbs locomotor forces, yet is heavy and thus...
Preprint
We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich ( Struthio camelus ) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this mod...
Preprint
Full-text available
We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich ( Struthio camelus ) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this mod...
Article
Full-text available
In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogeny influence standing and movin...
Article
Full-text available
Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought...
Preprint
Full-text available
In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogenyinfluence standing and moving...
Preprint
In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these concerns are clear, a viable solution is still elusive. Part of the solution lies in knowing how anatomical changes in afflicted body systems that occur across ontogenyinfluence standing and moving...
Preprint
Full-text available
Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought...
Preprint
Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought...