P A Kramer
Datos Biográficos
| ID | 49941 |
|---|---|
| NOMBRE | P A Kramer |
| NOMBRES | P A |
| APELLIDO | Kramer |
| FIRMA | KRAMER P A |
| AFILIACIONES | University of Washington |
| ORCID | 0000-0002-6435-9130 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 18 |
| TOTAL DE CITAS | 87 |
| TOTAL COMO AUTOR | 18 |
| TOTAL COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 1998 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2026 |
| ÍNDICE H | 5 |
Variation in the Angle of the First Pedal Ray Relative to the Midline of the Foot by Sex and Parity History
Association Between Parity and Bone Mineral Density in the National Health and Nutrition Examination Survey
OBJECTIVE: Bone remodeling relies on a dynamic process of concurrent deposition and resorption of bone material, which regulates bone mineral density (BMD), a critical component of overall bone health. Chronic dysregulation of the remodeling process during an individual's life can result in low BMD, osteoporosis, reduced mineral reserves and/or increased fracture risk. Prior studies have investigated the link between parity and BMD, positing that…
Sensitivity of musculoskeletal models to variation in muscle architecture parameters
Musculoskeletal models, like all theoretical models of physical processes, depend on the assumptions needed to construct the model. For musculoskeletal models, these assumptions include, among other things, the kinematic data, the kinetic data and the muscle parameters. The former (dynamic) data can be acquired relatively easily from living subjects, but the latter are usually based on limited information, frequently determined from cadaver studi…
Estimating the in vivo location of the talus from external surface landmarks
Objectives Finite element analysis has gained popularity in anthropological research to connect morphological form to measurable function but requires that loads are applied at appropriate anatomical locations. This is challenging for the ankle because the joint surfaces are not easily determined given their deep anatomical location. While the location of the talonavicular and subtalar joints can be directly determined via medical imaging, regres…
Radiographic measurements of the talus and calcaneus in the adult pes planus foot type
OBJECTIVE: A distinctive feature of the modern human foot is the presence of a medial longitudinal arch when weight-bearing. Although the talus and calcaneus play a major role in the structure and function of the human foot, the association between the morphology of these bones and longitudinal arch height has not been fully investigated. A better understanding of this relationship may assist in the interpretation of pedal remains of fossil homin…
Minimal energetic expenditure of women walking burdened on gradients in urban environments
Objectives The objective is to understand the walking energy expenditure of women in urban environments (i.e., over‐ground), using mass, velocity, gradient (incline and decline), and burden as predictors. In addition, we use an equation to determine the gradient associated with the minimum energy expenditure of walking. Methods To do this, we assessed the volumetric consumption of oxygen (VO 2 ) of ten females (ages: 22–40 years) with a portable …
Brief Communication
Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed. The mean values of the cal…
Sacral Orientation in Hominin Evolution
Sagittal sacral orientation within the pelvic girdle of humans is a key component of posture and obstetrics. On the one hand, sacral orientation has direct influence on the lumbar curvature; while on the other hand, it has an impact on the dorsoventral dimension of the birth canal. In this study, we aim to explore the evolution of sacral orientation in the sagittal plane and its relationship with the lumbar curvature in hominins. To do this, we m…
Brief communication
The estimated lower limb length (0.761–0.793 m) of the partial skeleton of Australopithecus afarensis from Woranso‐Mille (KSD‐VP‐1/1) is outside the previously known range for Australopithecus and within the range of modern humans. The lower limb length of KSD‐VP‐1/1 is particularly intriguing when juxtaposed against the lower limb length estimate of the other partial skeleton of A. afarensis , AL 288‐1 (0.525 m). A sample of 36 children (age, >7…
Lumbar lordosis of extinct hominins
The lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship betwee…
The effect on energy expenditure of walking on gradients or carrying burdens
The effectiveness of people walking while carrying burdens and/or on gradients has been of interest to anthropologists for some time. No empirical equation exists, however, to assess the energetic expenditure of individuals traveling downhill with burdens and whether or not all people increase their energetic expenditure over unburdened level travel when carrying relatively light burdens ( 80% of the variation in energetic expenditure. These new …
Bipedal Form and Locomotor Function
Volumes have been written to address the locomotor anatomy of hominids, yet despite this intense scrutiny, we still do not fully understand the relationship between bipedal form and locomotor function. Energetic expendi ture (as a measure of locomotor function) can be modeled using techniques that exploit empirical or theoretical methods, but none of these approaches fully captures how energetic expenditure varies within or among species at a par…
Stand and shuffle
Many reasons for the emergence of bipedalism have been proposed, including postural arguments which highlight that a sub‐optimal form of bipedalism (“shuffling”) might have been used by protohominids to cover short distances between resources that require bipedal standing. Bipedal shuffling may have been employed because it avoids the cost of raising the trunk from the quadrupedal orientation, which we assume is the habitual locomotor stance of p…
Modern humans are not (quite) isometric
Allometric relationships are important sources of information for many types of anthropological and biological research. The baseline for all allometric relationships is isometry (or geometric similarity), the principal that shape is invariant of size. Here, we formally test for geometric similarity in modern humans, looking at the maximum lengths of four long bones (humerus, radius, femur, and tibia). We use Jolicoeur's multivariate allometry me…
The Behavioral Ecology of Locomotion
Locomotor energetics and leg length in hominid bipedality
The costs of human locomotion
This article investigates maternal investment in child carrying and presents a method for determining when it is energetically advantageous for a mother to carry her child rather than force her child to walk independently. I calculate maternal and child energy consumption while walking and develop correction factors to facilitate making these energy calculations for young children. In addition, I investigate the effect of maternal burdens in addi…
The costs of human locomotion
This article investigates maternal investment in child carrying and presents a method for determining when it is energetically advantageous for a mother to carry her child rather than force her child to walk independently. I calculate maternal and child energy consumption while walking and develop correction factors to facilitate making these energy calculations for young children. In addition, I investigate the effect of maternal burdens in addi…
Locomotor energetics and leg length in hominid bipedality
Lumbar lordosis of extinct hominins
The lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship betwee…
Modern humans are not (quite) isometric
Allometric relationships are important sources of information for many types of anthropological and biological research. The baseline for all allometric relationships is isometry (or geometric similarity), the principal that shape is invariant of size. Here, we formally test for geometric similarity in modern humans, looking at the maximum lengths of four long bones (humerus, radius, femur, and tibia). We use Jolicoeur's multivariate allometry me…
Bipedal Form and Locomotor Function
Volumes have been written to address the locomotor anatomy of hominids, yet despite this intense scrutiny, we still do not fully understand the relationship between bipedal form and locomotor function. Energetic expendi ture (as a measure of locomotor function) can be modeled using techniques that exploit empirical or theoretical methods, but none of these approaches fully captures how energetic expenditure varies within or among species at a par…
Brief Communication
Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed. The mean values of the cal…
Sensitivity of musculoskeletal models to variation in muscle architecture parameters
Musculoskeletal models, like all theoretical models of physical processes, depend on the assumptions needed to construct the model. For musculoskeletal models, these assumptions include, among other things, the kinematic data, the kinetic data and the muscle parameters. The former (dynamic) data can be acquired relatively easily from living subjects, but the latter are usually based on limited information, frequently determined from cadaver studi…
The costs of human locomotion
This article investigates maternal investment in child carrying and presents a method for determining when it is energetically advantageous for a mother to carry her child rather than force her child to walk independently. I calculate maternal and child energy consumption while walking and develop correction factors to facilitate making these energy calculations for young children. In addition, I investigate the effect of maternal burdens in addi…
The costs of human locomotion
This article investigates maternal investment in child carrying and presents a method for determining when it is energetically advantageous for a mother to carry her child rather than force her child to walk independently. I calculate maternal and child energy consumption while walking and develop correction factors to facilitate making these energy calculations for young children. In addition, I investigate the effect of maternal burdens in addi…
Locomotor energetics and leg length in hominid bipedality
The Behavioral Ecology of Locomotion
Stand and shuffle
Many reasons for the emergence of bipedalism have been proposed, including postural arguments which highlight that a sub‐optimal form of bipedalism (“shuffling”) might have been used by protohominids to cover short distances between resources that require bipedal standing. Bipedal shuffling may have been employed because it avoids the cost of raising the trunk from the quadrupedal orientation, which we assume is the habitual locomotor stance of p…
Modern humans are not (quite) isometric
Allometric relationships are important sources of information for many types of anthropological and biological research. The baseline for all allometric relationships is isometry (or geometric similarity), the principal that shape is invariant of size. Here, we formally test for geometric similarity in modern humans, looking at the maximum lengths of four long bones (humerus, radius, femur, and tibia). We use Jolicoeur's multivariate allometry me…
Bipedal Form and Locomotor Function
Volumes have been written to address the locomotor anatomy of hominids, yet despite this intense scrutiny, we still do not fully understand the relationship between bipedal form and locomotor function. Energetic expendi ture (as a measure of locomotor function) can be modeled using techniques that exploit empirical or theoretical methods, but none of these approaches fully captures how energetic expenditure varies within or among species at a par…
The effect on energy expenditure of walking on gradients or carrying burdens
The effectiveness of people walking while carrying burdens and/or on gradients has been of interest to anthropologists for some time. No empirical equation exists, however, to assess the energetic expenditure of individuals traveling downhill with burdens and whether or not all people increase their energetic expenditure over unburdened level travel when carrying relatively light burdens ( 80% of the variation in energetic expenditure. These new …
Brief communication
The estimated lower limb length (0.761–0.793 m) of the partial skeleton of Australopithecus afarensis from Woranso‐Mille (KSD‐VP‐1/1) is outside the previously known range for Australopithecus and within the range of modern humans. The lower limb length of KSD‐VP‐1/1 is particularly intriguing when juxtaposed against the lower limb length estimate of the other partial skeleton of A. afarensis , AL 288‐1 (0.525 m). A sample of 36 children (age, >7…
Lumbar lordosis of extinct hominins
The lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship betwee…
Sacral Orientation in Hominin Evolution
Sagittal sacral orientation within the pelvic girdle of humans is a key component of posture and obstetrics. On the one hand, sacral orientation has direct influence on the lumbar curvature; while on the other hand, it has an impact on the dorsoventral dimension of the birth canal. In this study, we aim to explore the evolution of sacral orientation in the sagittal plane and its relationship with the lumbar curvature in hominins. To do this, we m…
Brief Communication
Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed. The mean values of the cal…
Minimal energetic expenditure of women walking burdened on gradients in urban environments
Objectives The objective is to understand the walking energy expenditure of women in urban environments (i.e., over‐ground), using mass, velocity, gradient (incline and decline), and burden as predictors. In addition, we use an equation to determine the gradient associated with the minimum energy expenditure of walking. Methods To do this, we assessed the volumetric consumption of oxygen (VO 2 ) of ten females (ages: 22–40 years) with a portable …
Estimating the in vivo location of the talus from external surface landmarks
Objectives Finite element analysis has gained popularity in anthropological research to connect morphological form to measurable function but requires that loads are applied at appropriate anatomical locations. This is challenging for the ankle because the joint surfaces are not easily determined given their deep anatomical location. While the location of the talonavicular and subtalar joints can be directly determined via medical imaging, regres…
Radiographic measurements of the talus and calcaneus in the adult pes planus foot type
OBJECTIVE: A distinctive feature of the modern human foot is the presence of a medial longitudinal arch when weight-bearing. Although the talus and calcaneus play a major role in the structure and function of the human foot, the association between the morphology of these bones and longitudinal arch height has not been fully investigated. A better understanding of this relationship may assist in the interpretation of pedal remains of fossil homin…
Sensitivity of musculoskeletal models to variation in muscle architecture parameters
Musculoskeletal models, like all theoretical models of physical processes, depend on the assumptions needed to construct the model. For musculoskeletal models, these assumptions include, among other things, the kinematic data, the kinetic data and the muscle parameters. The former (dynamic) data can be acquired relatively easily from living subjects, but the latter are usually based on limited information, frequently determined from cadaver studi…
Association Between Parity and Bone Mineral Density in the National Health and Nutrition Examination Survey
OBJECTIVE: Bone remodeling relies on a dynamic process of concurrent deposition and resorption of bone material, which regulates bone mineral density (BMD), a critical component of overall bone health. Chronic dysregulation of the remodeling process during an individual's life can result in low BMD, osteoporosis, reduced mineral reserves and/or increased fracture risk. Prior studies have investigated the link between parity and BMD, positing that…
Variation in the Angle of the First Pedal Ray Relative to the Midline of the Foot by Sex and Parity History
Anatomy (10 obras) · Biology (10 obras) · Medicine (9 obras) · Anatomy (8 obras) · Geography (7 obras) · Evolutionary biology (6 obras) · Mathematics (6 obras) · Bipedalism (5 obras) · Computer Science (5 obras) · Evolution and Paleontology Studies (5 obras)