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Wheelchair users have a higher risk of developing pressure ulcers due to prolonged seated pressure. Pressure ulcers can be painful, may require surgical intervention, and even become life-threatening if infection occurs. To prevent pressure ulcers from forming the patient must either offload themselves or rely on a caregiver to move them allowing pressure redistribution over the seated area. In this work, we designed a dynamic air cushion to relieve pressure on loaded areas using sequences of inflation and deflation of the air cushion cells. The purpose of these sequences is to offload pressure from high-risk areas. To evaluate the effect of the alternating sequences on seated pressure and blood perfusion, we recorded interface pressure, skin blood flow, superficial tissue oxygen saturation, blood concentrations of oxygenated hemoglobin, and deoxygenated hemoglobin from twenty-one healthy volunteers who were asked to sit on the air cushion for static mode recording (3 min) and during the inflation/deflation sequences (up to 22 min). The alternating sequences consisted of ten combined inflation and deflation steps. Results showed that, after applying the alternating sequences, interface pressure reduced significantly (p=0.02) compared to the static mode. Moreover, the coefficient of variation of the seated pressure was higher (p<0.001) during the alternation sequence compared to the static mode. However, interface pressure under the right and left ischial tuberosities increased (p<0.001) during the alternation sequence compared to the static mode. In addition, during the alternating sequences, males had larger dispersion index values of both right and left ischial tuberosities pressure compared to females. Furthermore, the maximum value of oxygen saturation (p=0.04) and skin blood flow (p=0.001) increased during the pressure alternation sequences compared to the static mode. The study findings highlighted the positive effects of the designed dynamic air-cushion to relieve pressure on compressed areas and enhance blood perfusion similar to manual offloading approaches. The outcomes of this study are encouraging to evaluate the performance of the designed air cushion in studies involving wheelchair users.

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BACKGROUND: Individuals with limited mobility can spend prolonged periods in leisure chairs, increasing their risk of developing a seated acquired pressure ulcer. The present study aims to use objective measures of posture and tissue viability to identify the associated risks of leisure chair related pressure ulcers. METHODS: Healthy participants (n = 13) were recruited to sit on a leisure chair with either a viscoelastic foam or air cushion. Participants were asked to adopt four different postures for a period of 10 min followed by a 10 min refractory period. Measurements at the leisure chair-participant interface included interface pressure, transcutaneous tissue gas tensions at the ischial tuberosities, accelerometer data collected from the sternum and subjective comfort levels. RESULTS: Results indicated that interface pressures remained consistent, with peak pressure index values of less than 60 mmHg across all conditions. A proportion of participants exhibited decreased oxygen tensions associated with increased carbon dioxide tensions during one or more test condition. This was particularly prevalent during the right lean posture on the air cushion (46%). In all cases, normal tissue viability was restored during standing. The accelerometer was able to detect significant changes (p < 0.05) in relative trunk angles during slump and right lean when compared to optimal sitting posture. CONCLUSION: Commercially available leisure chairs have little evidence to support their pressure relieving properties. This study revealed that a proportion of healthy individuals demonstrated a compromised tissue viability in specific postures. Further research is required to assess the impact of these sitting conditions in vulnerable individuals.

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BACKGROUND: High strain in soft tissues that overly bony prominences are considered a risk factor for pressure ulcers (PUs) following spinal cord impairment (SCI) and have been computed using Finite Element methods (FEM). The aim of this study was to translate a MRI protocol into ultrasound (US) and determine between-operator reliability of expert sonographers measuring diameter of the inferior curvature of the ischial tuberosity (IT) and the thickness of the overlying soft tissue layers on able-bodied (AB) and SCI using real-time ultrasound. MATERIAL AND METHODS: Part 1: Fourteen AB participants with a mean age of 36.7 ± 12.09 years with 7 males and 7 females had their 3 soft tissue layers in loaded and unloaded sitting measured independently by 2 sonographers: tendon/muscle, skin/fat and total soft tissue and the diameter of the IT in its short and long axis. Part 2: Nineteen participants with SCI were screened, three were excluded due to abnormal skin signs, and eight participants (42%) were excluded for abnormal US signs with normal skin. Eight SCI participants with a mean age of 31.6 ± 13.6 years and all male with 4 paraplegics and 4 tetraplegics were measured by the same sonographers for skin, fat, tendon, muscle and total. Skin/fat and tendon/muscle were computed. RESULTS: AB between-operator reliability was good (ICC = 0.81-0.90) for 3 soft tissues layers in unloaded and loaded sitting and poor for both IT short and long axis (ICC = -0.028 and -0.01). SCI between-operator reliability was good in unloaded and loaded for total, muscle, fat, skin/fat, tendon/muscle (ICC = 0.75-0.97) and poor for tendon (ICC = 0.26 unloaded and ICC = -0.71 loaded) and skin (ICC = 0.37 unloaded and ICC = 0.10). CONCLUSION: A MRI protocol was successfully adapted for a reliable 3 soft tissue layer model and could be used in a 2-D FEM model designed to estimate soft tissue strain as a novel risk factor for the development of a PU.

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AIM OF THE STUDY: Tissue deformation is recognized as an important risk factor for pressure injuries. This study investigated the effects of anatomy and wheelchair cushion type on tissue deformation. MATERIALS AND METHODS: Direct 3-dimensional tissue deformation response was measured for six participants sitting on six different wheelchair cushions using MR imaging. Two participants had a traumatic spinal cord injury (SCI) within one year of the assessment, two sustained traumatic SCI at least 13 years prior, and two were without SCI. Tissue deformation was quantified using the difference in volume of tissue beneath the ischial tuberosity (IT) between unloaded and loaded (sitting) conditions. RESULTS: The participants with SCI tended to have less muscle tissue volume beneath their ITs while sitting compared to participants without SCI. Reductions in muscle and fat volumes in the loaded conditions varied depending on both cushion and participant. Higher interface pressures tended to be associated with lower unloaded tissue thicknesses. CONCLUSION: The study showed no single cushion type tested produced the lowest amount of tissue deformation across all participants. Individual anatomy and cushion type affect deformation response of tissue and related pressure injury risk.

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Ischial pressure ulcer is an important risk for every paraplegic person and a major public health issue. Pressure ulcers appear following excessive compression of buttock's soft tissues by bony structures, and particularly in ischial and sacral bones. Current prevention techniques are mainly based on daily skin inspection to spot red patches or injuries. Nevertheless, most pressure ulcers occur internally and are difficult to detect early. Estimating internal strains within soft tissues could help to evaluate the risk of pressure ulcer. A subject-specific biomechanical model could be used to assess internal strains from measured skin surface pressures. However, a realistic 3D non-linear Finite Element buttock model, with different layers of tissue materials for skin, fat and muscles, requires somewhere between minutes and hours to compute, therefore forbidding its use in a real-time daily prevention context. In this article, we propose to optimize these computations by using a reduced order modeling technique (ROM) based on proper orthogonal decompositions of the pressure and strain fields coupled with a machine learning method. ROM allows strains to be evaluated inside the model interactively (i.e. in less than a second) for any pressure field measured below the buttocks. In our case, with only 19 modes of variation of pressure patterns, an error divergence of one percent is observed compared to the full scale simulation for evaluating the strain field. This reduced model could therefore be the first step towards interactive pressure ulcer prevention in a daily set-up.

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The gold standard tool for measuring periprosthetic bone mineral density (BMD) is dual-energy X-ray absorptiometry (DXA). However, resolution of the method is limited due to the aggregation of pixel data into large regions of interest for clinical and statistical analysis. We have previously validated a region-free analysis method (DXA-RFA) for quantitating BMD change at the pixel level around femoral prostheses. Here, we applied the DXA-RFA method to the pelvis, and quantitated its precision in this setting using repeated DXA scans taken on the same day after repositioning in 29 patients after total hip arthroplasty. Scans were semiautomatically segmented using edge detection, intensity thresholding, and morphologic operations, and elastically registered to a common template generated through generalized Procrustes analysis. Pixel-wise BMD precision between repeated scans was expressed as a coefficient of variation %. Longitudinal BMD change was assessed in an independent group of 24 patients followed up for 260 wk. DXA-RFA spatial resolution of 0.31 mm2 provided approximately 12,500 data points per scan. The median data-point precision was 17.8% (interquartile range 14.3%-22.7%). The anatomic distribution of the precision errors showed poorer precision at the bone borders and superior precision to the obturator foramen. Evaluation of longitudinal BMD showed focal BMD change at 260 wk of -26.8% adjacent to the prosthesis-bone interface (1% of bone map area). In contrast, BMD change of +39.0% was observed at the outer aspect of the ischium (3% of bone map area). Pelvic DXA-RFA is less precise than conventional DXA analysis. However, it is sensitive for detecting local BMD change events in groups of patients, and provides a novel tool for quantitating local bone mass after joint replacement. Using this method, we were able to resolve BMD change over small areas adjacent to the implant-bone interface and in the ischial region over 260 wk after total hip arthroplasty.

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OBJECTIVE: The primary aim of this study was to determine if ischiofemoral space (IFS) dimensions vary with changes in hip flexion as a result of placing a bolster behind the knees during magnetic resonance imaging (MRI). A secondary aim was to determine if IFS dimensions vary between supine and prone hip neutral positions. DESIGN: The study employed a prospective design. SETTING: Sports medicine center within a tertiary care institution. PARTICIPANTS: Five male and five female adult subjects (age mean = 29.2, range = 23-35; body mass index [BMI] mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. METHODS: An axial, T1-weighted MRI sequence of the pelvis was obtained of each subject in a supine position with their hips in neutral and flexed positions, and in a prone position with their hips in neutral position. Supine hip flexion was induced by placing a standard, 9-cm-diameter MRI knee bolster under the subject's knees. The order of image acquisition (supine hip neutral, supine hip flexed, prone hip neutral) was randomized. The IFS dimensions were then measured on a separate workstation. The investigator performing the IFS measurements was blinded to the subject position for each image. MAIN OUTCOME MEASUREMENTS: The main outcome measurements were the IFS dimensions acquired with MRI. RESULTS: The mean IFS dimensions in the prone position were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). In the supine hip neutral position, the IFS dimensions were 25.1 (SD 5.6) mm. The mean difference between the two positions of 3.15 (3.6) mm was statistically significant (95 % CI of the difference = 1.4 to 4.8 mm, t19 = 3.911, p = .001). The mean IFS dimensions in the hip flexed position were 36.9 (SD 5.7) mm. The mean difference between the two supine positions of 11.8 (4.1) mm was statistically significant (95 % CI of the difference = 9.9 to 13.7 mm, t19 = 12.716, p < .001). CONCLUSIONS: Our findings demonstrate that the IFS measurements obtained with MRI are dependent upon patient positioning with respect to hip flexion and supine versus prone positions. This finding has implications when evaluating for ischiofemoral impingement, an entity resulting in hip and/or buttock pain secondary to impingement of the quadratus femoris muscle within a pathologically narrowed IFS. One will need to account for patient hip flexion and supine versus prone positioning when evaluating individuals with suspected ischiofemoral impingement.

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El objetivo de este estudio es comprobar si el estilo de natación en el que están especializados los nadadores, influye sobre la extensibilidad isquiosural de los deportistas que han participado en esta investigación. El test empleado para este trabajo es el test "sit and reach". Se ha medido la extensibilidad isquiosural de todos los nadadores (N=36) de ambos sexos, que entrenan en un centro de tecnificación acuático español. La edad de los participantes del estudio oscila entre los 13 y los 17 años. Esta población de nadadores ha sido dividida en cuatro grupos diferentes, dependiendo del estilo de natación en el que están especializados (crol, espalda, braza y mariposa). Para conocer la influencia del estilo natación sobre los resultados obtenidos en el test "sit and reach", se ha aplicado un test inicial y nueve meses más tarde un test final, lo que ha permitido conocer también la evolución de las mediciones. Como conclusión, la extensibilidad isquiosural y su evolución, no está condicionada por el estilo de natación en el que están especializados los nadadores que han participado en este estudio (AU)

The aim of this research is to verify the swimming style in which swimmers are specialized, have has influences hamstring extensibility athletes who have had participated in this research. The employed test for this work was the "sits and reach" test. It was measured hamstring extensibility of all swimmers (N = 36) of both sexes, who train in Spanish aquatic center modernization. The age of the study participants is between 13 and 17 years. This population of swimmers has been divided into four different groups, depending on the style of swimming in which they are specialized (crawl, backstroke, breaststroke and butterfly). To determine the influence of swimming style on the results obtained in the test "sit and reach", it having had applied an initial test before, and a final test nine months later, which have had permitted also know the measurements evolution. In conclusion, the hamstring muscle extensibility and its evolution have had being not conditioned by swimming style of the swimmers (AU)

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Introducción: la realización de estiramientos de la musculatura isquiosural, dos sesiones por semana en días alternos, produce mejoras significativas en escolares. Objetivo: comparar los efectos de un programa de estiramientos de la musculatura isquiosural realizado en las clases de educación física en dos grupos de adolescentes, en función de la distribución semanal de sus sesiones de clase (sesiones alternas vs. sesiones consecutivas). Metodología: cincuenta y ocho estudiantes adolescentes realizaron un programa de estiramientos estático-activos de la musculatura isquiosural durante cinco semanas, ejecutados al comienzo de dos clases semanales de educación física, con una duración total de cinco minutos. Los alumnos fueron divididos en dos grupos: el grupo A, formado por 30 alumnos, tenían las clases en días consecutivos (lunes-martes) y el grupo B, compuesto por 29 alumnos, en días no consecutivos (martes-viernes). La extensibilidad de la musculatura isquiosural se evalúo mediante el test sit-and-reach antes del inicio del programa (pre-test) y tras finalizar el mismo (post-test). Resultados y discusión: se encontró una mejora significativa de la distancia alcanzada en el test sit-and-reach tanto en el grupo A (+2,15 cm) (p = 0,003) como en el grupo B (+2,31 cm) (p 0,05). Conclusiones: la aplicación de un programa de intervención con una duración de cinco semanas y una frecuencia de dos sesiones semanales produce mejoras en la extensibilidad isquiosural en escolares. La distribución semanal de las sesiones no influye en los resultados encontrados (AU)

Introduction: students who do hamstring stretching exercises, twice per week on alternate days, have showed significant increases on extensibility. Objective: to compare the effects of a hamstring stretching program includes in the physical education classes in booth groups of adolescent, which had a different class session weekly distribution (non-consecutive sessions vs. consecutive sessions). Method: fifty-eight adolescent students did a static-active stretching program on hamstring in the warm-up of both weekly physical education sessions for five weeks. The total duration of the stretching was five minutes. Students were divided in two groups: group A, with 30 students, had consecutive sessions (monday-tuesday), and the group B, with 29 students, had non-consecutive sessions (tuesday-friday). Hamstring extensibility was evaluated with the sit-and-reach test before (pre-test) and after (post-test) the intervention program. Results and discussion: there was found a significant increase in the sit-and-reach score in the group A (+2,15 cm) (p = 0.003) and in the group B (+2,31 cm) (p 0.05). Conclusions: the implementation of an intervention program for five weeks, twice sessions a week, induded increases on hamstring extensibility in students. The class session weekly distribution does not affect the results (AU)

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Pressure ulcers are hazardous to people with diminished sensory and motor functions who remain in the same position for a long time. An important reason for the occurrence of pressure ulcers is the inability of wheelchair users to make postural changes by themselves with no appropriate method of pressure release. In this study, we researched the effects of applying an air cell inflate-deflate alternating sequence cushion prototype to relieve pressure from tissue loaded areas. Moreover, the hypothesis that the alternating sequence could stimulate blood reperfusion in loaded tissues and redistribute interface pressure on support area was also tested. Ten healthy volunteers were recruited to try the prototype cushion for 65 min of continuous loading; 5 min on static mode and 60 min on alternating mode. This study was conducted on healthy people because their sensitivity allowed them to state clearly and in detail, in a feedback questionnaire, any discomfort experienced with the use of our cushion. In order to address our hypothesis, interface pressure, and bilateral ischial oxygenated and deoxygenated hemoglobin were measured. After applying the alternating cushion, the interface pressure was redistributed over a larger contact area. Besides, blood perfusion was improved according to increments in oxygenated hemoglobin and decrements in deoxygenated hemoglobin of ischial regions during loaded condition. Feedback questionnaire showed that the participants did not feel pain or discomfort using the alternating cushion. The overall results showed positive effects on healthy tissue which has encouraged us to design a study involving subjects who use wheelchairs for mobility.

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Introducción: la disposición del raquis lumbo-sacro y la distancia alcanzada en el test sit-and-reach han sido propuestas para valorar la extensibilidad isquiosural, siendo su validez diferente en función de la población analizada. Objetivo: determinar la validez del ángulo lumbo-horizontal en flexión y la distancia alcanzada en el test sitand-reach como criterio de extensibilidad isquiosural en mujeres mayores. Metodología: un total de 120 mujeres mayores realizaron aleatoriamente los test de elevación de pierna recta (EPR) con ambas piernas y el test sit-and-reach (SR). En este último se valoró la distancia alcanzada y la disposición del raquis lumbo-sacro (L-Hfx) al alcanzar la posición de máxima flexión del tronco. Resultados y discusión: los valores medios en el EPR fueron 81,70 ± 13,83º y 82,10 ± 14,36º en las piernas izquierda y derecha, respectivamente. La media del EPR de ambas piernas fue de 81,90 ± 12,70º. La distancia media en el SR fue de -1,54 ± 8,09 cm. En el L-Hfx, el valor medio fue de 91,08º ± 9,32º. La correlación entre el test EPR medio de ambas piernas respecto a la distancia alcanzada en el test DDP y el ángulo L-Hfx fueron moderados (L-Hfx: r = -0,72, p < 0,01; SR: r = 0,70, p < 0,01). Ambas variables, de forma independiente, explicaron alrededor del 50% de la varianza (L-Hfx: R2 = 0,52; p < 0,001; SR: R2 = 0,49; p < 0,001). Conclusiones: la validez de la disposición del raquis lumbo-sacro en mujeres mayores es moderada, siendo similar a la obtenida por la distancia alcanzada en el test sit-and-reach (AU)

Introduction: lumbo-sacral posture and the sit-andreach score have been proposed as measures of hamstring extensibility. However, the validity is influenced by sample characteristics. Objective: to determine the validity of lumbo-horizontal angle and score in the sit-and-reach test as measures of hamstring extensibility in older women. Method: a hundred and twenty older women performed the straight leg raise test with both leg, and the sit-and-reach test (SR) in a random order. For the sitand-reach test, the score and the lumbo-sacral posture in bending (lumbo-horizontal angle, L-Hfx) were measured. Results and discussion: the mean values of straight leg raise in left and right leg were 81.70 ± 13.83º and 82.10 ± 14.36º, respectively. The mean value of EPR of both legs was 81.90 ± 12.70º. The mean values of SR score and L-Hfx were -1.54 ± 8.09 cm and 91.08º ± 9.32º, respectively. The correlation values between the mean straight leg raise test with respect to lumbo-sacral posture and SR score were moderate (L-Hfx: r = -0.72, p < 0.01; SR: r = 0.70, p < 0.01). Both variables independently explained about 50% of the variance (L-Hfx: R2 = 0.52, p < 0,001; SR: R2 = 0.49, p < 0,001). Conclusions: the validity of lumbo-sacral posture in bending as measure of hamstring muscle extensibility on older women is moderate, with similar values than SR score (AU)

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Measuring shear force is crucial for investigating the pathology and treatment of pressure ulcers. In this study, we introduced a bi-axial shear transducer based on strain gauges as a new shear sensor. The sensor consisted of aluminum and polyvinyl chloride plates placed between quadrangular aluminum plates. On the middle plate, two strain gauges were placed orthogonal to one another. The shear sensor (54 mm × 54 mm × 4.1 mm), which was validated by using standard weights, displayed high accuracy and precision (measurement range, -50 to 50 N; sensitivity, 0.3N; linear relationship, R(2)=0.9625; crosstalk error, 0.635% ± 0.031%; equipment variation, 4.183). The shear force on the interface between the human body and a stand-up wheelchair was measured during sitting or standing movements, using two mats (44.8 cm × 44.8 cm per mat) that consisted of 24 shear sensors. Shear forces on the sacrum and ischium were almost five times higher (15.5 N at last posture) than those on other sites (3.5 N on average) during experiments periods. In conclusion, the proposed shear sensor may be reliable and useful for measuring the shear force on human-machine interfaces.

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OBJECTIVE: Clinicians commonly recommend that power wheelchair users with spinal cord injury perform wheelchair tilt and recline maneuvers to redistribute seating loads away from the ischial tuberosities. However, ischial pressure reduction may be accompanied by coccygeal pressure increases. Although the coccyx is among the most common sites of pressure ulcers, few studies have reported coccygeal interface pressure. The purpose of this study was to investigate both ischial and coccygeal interface pressures in response to changes in wheelchair tilt and recline angles. DESIGN: Thirteen power wheelchair users were recruited into this study. Six combinations of wheelchair tilt (15, 25, and 35 degrees) and recline (10 and 30 degrees, corresponding to traditional recline conventions of 100 and 120 degrees, respectively) angles were tested in random order. Each combination was tested with 5 mins of upright sitting, 5 mins of tilt and recline, as well as 5 mins of maximal pressure relief recovery. Peak pressure indices were calculated at the ischial and coccygeal sites. RESULTS: Ischial pressures monotonically decreased in response to increasing combinations of tilt and recline. Increments of 15 degrees of tilt did not produce significant differences under either recline angle, whereas increments of 25 degrees of tilt produced significant differences under both recline angles. Coccygeal pressures increased in response to the four smallest (of six) combinations of tilt and recline, whereas they decreased in response to the largest two combinations. CONCLUSIONS: Ischial pressures seemed to be redistributed to the coccyx in response to the four smallest angle combinations and redistributed to the back support in response to the two largest angle combinations. Future work should confirm this pressure redistribution to the back support and determine the back support locations of redistribution.

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OBJECTIVE: Investigate the effect of a brimless interface design compared with ischial ramus containment (IRC) of interfaces when using vacuum-assisted suspension (VAS) on transfemoral amputees (TFAs). DESIGN: Randomized experimental crossover. SETTING: Household, community, and clinic. PARTICIPANTS: Unilateral TFAs (N=12 enrolled, N=10 analyzed). Mean age: 42.9 years. Mean residual limb length: 60.3% of the sound side femur length. Participants' mean time as an amputee: 8.3 years and median AMP score: 43. INTERVENTIONS: (1) IRC VAS interface, and (2) brimless VAS interface. Average medial wall height for IRC interfaces was 0.7cm proximal to the distal-most aspect of the ischial tuberosity (IT). The medial wall on the brimless design was an average of 3.3cm distal to the distal-most aspect of the IT. MAIN OUTCOME MEASURES: Spatiotemporal gait parameters, limits of stability, four square step test, and subjective perception using the prosthetic evaluation questionnaire (PEQ). RESULTS: Step length was significantly improved towards the IRC (p=0.04), when calculating degree of asymmetry. Base of support was significantly narrowed toward the brimless (p=0.03). All subjective measures reached statistical significance in favor of improvement with the brimless design, compared to the IRC. CONCLUSIONS: The brimless design was equivalent to IRC in most gait and balance outcome measures. However, step length was more symmetrical toward the IRC while base of support was narrowed toward the brimless demonstrating mixed inconsistent performance changes. Further, the PEQ demonstrated significant subjective improvements in prosthetic related function and quality of life when participants used the brimless design. Brimless interface design may be a clinically viable choice.

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It has been shown that thigh-seat contact-surface influences performance of isometric push-force with upper-limbs. The push-force performance is higher when subjects are seated with partial ischio-femoral / seat contact than when they are seated with full ischio-femoral contact. This was ascribed to greater pelvis and spine mobility induced by the short thigh-seat contact-surface. The present study tested the generalization of this hypothesis during movements involving body segment displacement, namely trunk flexion (TF) and sit-to-stand (STS) motor tasks. Both motor tasks were carried out in similar conditions to those implemented in the isometric push-force tasks, i.e. full ischio-femoral / seat contact (100-IFC) and short ischio-femoral contact (30-IFC, i.e. 30% of full ischio-femoral / seat contact). Results showed that kinematic performances (maximal antero-posterior and vertical center of mass velocity and maximal backward displacement of center of pressure) in both motor tasks were higher in 30-IFC than in 100-IFC. In the sit-to-stand task, time of seat-off is shorter in 30-IFC. As the subject's initial global posture was comparable across the experimental conditions, it can be discarded as a source of performance change. It is discussed that it is the enhanced pelvis mobility induced by the sitting condition which is responsible for the increase of motor performance in both trunk flexion and sit-to-stand tasks. Our results highlight the role of joint mobility in motor performance.

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This article examines the utility of the ischium-pubic index (IPI), a sexing technique that compares the lengths of pubis and ischium. The ratio was adapted by Washburn from a primate index devised by Schultz and was tested by Washburn on documented remains from the Hamann-Todd Human Osteological Collection. The IPI is used by forensic investigators, and indeed, the method is found in standard forensic textbooks and thus appears to be valid to early-stage researchers. However, its reliability has been questioned by physical anthropologists almost from its inception due to the intrinsic subjectivity of locating the base point from which both lengths are taken. In addition, at least one variation of the original technique is found in the literature, which alters the base point profoundly. To explore both the original method and the ramifications of altering the base point, in this article the IPI is calculated from os coxae recovered from the Mary Rose, a 16th-century English warship lost in a documented disaster; the sample is assumed to be from males. Using the original index, 20.4% of individuals (11 of 54) or, viewing the remains as commingled, 15.5% of individual pelves (15 of 97) were misclassified. Results with the base point shifted were disastrous: 95.5% (21 of 22) individuals and 91.4% (32 of 35) pelves were misclassified. Accuracy may be influenced by the technician's expertise; however, when the original methodology is altered, the results become meaningless. This article aims to promote more careful reading of our sources and to suggest that the IPI is not appropriate as a tool for sexing forensic remains.

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BACKGROUND: Most posture problems encountered in persons who use wheelchairs in a seated posture for extended periods are related to sacral sitting due to posterior pelvic tilt. Posterior pelvic tilt places pressure and shearing force on the sacrococcygeal area that can lead to pressure ulcers, but the relationship between pelvic tilt and force applied to the sacrococcygeal and ischial tuberosity areas has not yet been investigated. OBJECTIVE: To investigate the relationships of posterior pelvic tilt in a seated posture with vertical force and horizontal force on the sacrococcygeal and ischial tuberosity areas. STUDY DESIGN: Repeated measures design. METHODS: Thirty male and female subjects aged ≥60 years sat in a measurement chair at varying pelvic tilt angles, and force on the sacrococcygeal and ischial tuberosity areas was measured. RESULTS: The pressure on the sacrococcygeal area increased with pelvic tilt in all subjects, with vertical force averaging 19% of the body weight at a pelvic tilt angle of 30°. The horizontal force on the sacrococcygeal area increased in 93% of the subjects, with an average increase equal to 3% of the body weight. CONCLUSIONS: We confirmed changes in vertical and horizontal forces on the sacrococcygeal and ischial tuberosity areas with a change in seated posture (pelvic tilt). CLINICAL RELEVANCE: We propose guidelines for rehabilitation practitioners working with wheelchair users to suggest improved ways of sitting in wheelchairs that avoid pelvic tilt angles that might promote pressure ulcers on the buttocks.

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Objetivo Conocer el efecto inmediato de la elongación muscular eléctrica por medio de corrientes interferenciales sobre la amplitud articular en sujetos con cortedad isquiotibial. Material y método Se realizó una valoración inicial (pretest) y final (postest) en donde la variable sometida a estudio fue la amplitud articular. Los test aplicados fueron el test de elevación de la pierna recta (EPR) y test de ángulo poplíteo (TAP). Se empleó una corriente interferencial bipolar con una modulación de la amplitud de la frecuencia de 100Hz y una frecuencia portadora de 4Khz.ResultadosSe obtuvieron mejoras estadísticamente significativas en la extensibilidad isquiosural tras aplicar elongación muscular eléctrica para ambos test angulares (p≤0,0001), siendo el tamaño efecto de R2=0,833 para TAP y de R2=0,752 para EPR. Conclusiones La aplicación de elongación muscular mediante corrientes interferenciales logra un aumento inmediato en la extensibilidad de la musculatura isquiosural tras ser medida con EPR y TAP(AU)

Objective To determine the immediate effect of electrical muscle elongation interferential currents through joint range of subjects with hamstring shortness. Material and method We performed an initial (pre-test) and final (post-test) assessment where the variable under study was the joint range. The tests applied were the straight leg raise test (SLR) and passive knee extension test (PKE). We used a bipolar interferential current with an amplitude modulation frequency of 100Hz and 4kHz carrier frequency. Results Statistically significant improvements were obtained in hamstring extensibility after applying electrical muscle elongation angle for both test (p ≤ 0.0001), with effect size for PKE of R2=0.833 and of R2=0.752 and for SLR. Conclusions The use of muscle elongation by interferential currents achieved an immediate increase in hamstring muscle extensibility after being measured by SLR and PKE (AU)

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This project, developed by the Design Studies Research Group at the Universidad Pontificia Bolivariana (UPB), presents a design proposal focused on human factors for ischial support for the stations of the Medellín Metro. An initial pilot scheme was developed on Platform 'A' of San Antonio - the most important transfer station. The methodology of the Ergonomics Research Division at UPB constituted the basis of the project. This methodology observes, analyses and draws conclusions of the conditions that optimize the User-Product-Context nexus, and in doing so defines design requirements which, in this proposal, centered on the needs of the users of the Medellín Metro. The Experimental Morphology Research Division provided technical support in the form of modelling, production and structural testing of the object. The proposal includes thematic units, themes and priority components for analysis and application in the design process. In addition, the project generates certain activities and moments that future designers can develop in a parallel manner, coherent with the vision of ergonomics. The methodology focused on the requirements of the users and took into account the existing space (the Metro System), thus establishing relationships of use that were coherent with the principles of ergonomics and design.

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Patients with Duchenne muscular dystrophy (DMD) lose ambulation by age 12. Long-term steroids have lengthened ambulation by 2-5 years. Ischial weight-bearing knee ankle foot orthoses prolong ambulation for 2-3 years. We report the outcome of the ambulatory status of a patient with DMD treated with daily steroid therapy and orthoses. This male patient was diagnosed with DMD at age of 2. He has been treated with daily steroids since age 7 years. He lost the ability to arise from the floor and walk up steps at age 14 and lost ambulation by age 16. He was fitted with orthoses at age 16 following surgical correction of his lower extremity contractures and regained independent ambulation. At age 20, he was able to stand independently in his orthoses and take steps with moderate support. We conclude that a combination of daily steroids and orthoses prolongs ambulation beyond that of the natural history DMD.

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