Shoulder kinetics and ultrasonography changes after performing a high-intensity task in spinal cord injury subjects and healthy controls.

This corrects the article DOI: 10.1038/sc.2015.140.

Abnormal cutaneous flexor reflex activity during controlled isometric plantarflexion in human spinal cord injury spasticity syndrome.

STUDY DESIGN: Although abnormal cutaneous reflex (CR) activity has been identified during gait after incomplete spinal cord injury (SCI), this activity has not been directly compared in subjects with and without the spasticity syndrome. OBJECTIVES: Characterisation of CR activity during controlled rest and 'ramp and hold' phases of controlled plantarflexion in subjects with and without the SCI spasticity syndrome. DESIGN: Transverse descriptive study with non-parametric group analysis. SETTING: SCI rehabilitation hospital. METHODS: Tibialis Anterior (TA) reflexes were evoked by innocuous cutaneous plantar sole stimulation during rest and ramp and hold phases of plantarflexion torque in non-injured subjects (n=10) and after SCI with (n=9) and without (n=10) hypertonia and/or involuntary spasm activity. Integrated TA reflex responses were analysed as total (50-300 ms) or short (50-200 ms) and long-latency (200-300 ms) activity. RESULTS: Total and long-latency TA activity was inhibited in non-injured subjects and the SCI group without the spasticity syndrome during plantarflexion torque but not in the SCI spasticity group. Furthermore, loss of TA reflex inhibition during plantarflexion correlated with time after SCI (ρ=0.79, P=0.009). Moreover, TA reflex activity inversely correlated with maximum plantarflexion torque in the spasticity group (ρ=-0.75, P=0.02), despite similar non-reflex TA electromyographic activity during plantarflexion after SCI in subjects with (0.11, 0.08-0.13 mV) or without the spasticity syndrome (0.09, 0.07-0.12 mV). CONCLUSIONS: This reflex testing procedure supports previously published evidence for abnormal CR activity after SCI and may characterise the progressive disinhibition of TA reflex activity during controlled plantarflexion in subjects diagnosed with the spasticity syndrome.

Shoulder kinetics and ultrasonography changes after performing a high-intensity task in spinal cord injury subjects and healthy controls.

STUDY DESIGN: This is a prospective and comparative study between two groups. OBJECTIVES: The objective of this study was to compare the changes in shoulder joint forces and their moments, as well as any possible ultrasound changes, when subjects with spinal cord injury (SCI) and healthy controls (CG) undertake a high-intensity manual wheelchair propulsion test. SETTING: This study was conducted in an inpatient SCI rehabilitation center. METHODS: A group of 22 subjects with SCI at level T2 or below who use a manual wheelchair (MWU), categorized as AIS grade A or B, were compared with a CG of 12 healthy subjects. Subjects in each group performed a high-intensity wheelchair propulsion test. The variables analyzed were shoulder joint forces and the moments at the beginning and at the end of the test. Ultrasound variables before and after the propulsion test were also analyzed. Correlations were also drawn between the ultrasonography and demographic variables. RESULTS: In both groups, peak shoulder forces and moments increased after the test in almost all directions. No differences in the ultrasound parameters were found. A greater long-axis biceps tendon thickness (LBTT) was associated with more shoulder pain according to WUSPI or VAS (r=0.428, P<0.05 and r=0.452, P<0.05, respectively). CONCLUSIONS: Shoulder joint forces and moments increase after an intense propulsion task. In subjects with SCI, these increases center on forces with less chance of producing subacromial damage. No changes are produced in ultrasonography variables, whereas a poorer clinical and functional evaluation of the shoulder of the MWUs appears to be related to a thicker long-axis biceps tendon.

Análisis biomecánico de la marcha en población pediátrica con lesión medular. Revisión de la casuística de una unidad de biomecánica hospitalaria / Biomechanic analysis of gait in the pediatric population of spinal cord injury. a review of the casuistics of a hospital biomechanics unit

Objetivo del estudio. Describir las características de los pacientes lesionados medulares en edad pediátrica cuyo patrón de marcha fue analizado en la Unidad de Biomecánica y Ayudas Técnicas del Hospital Nacional de Parapléjicos de Toledo. Material y métodos. Se realizó un estudio retrospectivo incluyendo a todos los pacientes que asistieron a la unidad, analizados entre enero de 2006 y marzo de 2010, edad inferior a 18 años, que fuesen pacientes ambulantes con/ sin ayudas técnicas e independencia de marcha con distancia mínima de 10 metros. Resultados. De los 48 pacientes incluidos en este estudio, el 53,1% eran varones frente al 46,9% de pacientes de sexo femenino. Las edades comprendidas están entre los dos años de edad hasta los 18 años, con una edad media de 12 años (+/- 2,31). La etiología de la lesión medular fue: traumática (29,16%), congénita (33,33%), neoplásica (8,33%) entre otros. En cuanto al nivel de lesión medular, en el 31,25% fueron lesiones cervicales, en el 29,16% fueron lumbares, en un 16,66% fueron dorsales, en el 2,08% fueron sacras y en el 20,83% el origen no fue medular. Conclusiones. La incidencia de lesión medular en edad pediátrica es muy pequeña, pero supone un gran reto asistencial, personal y social. La revisión bibliográfica realizada muestra la escasez de estudios referentes a esta patología y en pacientes en edades similares; así como estudios sobre el patrón de marcha que presentan estos pacientes(AU)

Objective. To describe the characteristics of patients with spinal cord injury in pediatric age whose gait pattern was analyzed in the Biomechanics and Technical Care Unit of the National Paraplegics Hospital of Toledo (Spain). Material and methods. A retrospective study including all patients attending the unit and analyzed between January 2006 and March 2010, younger than 18 years, who were outpatients with or without technical aids and independence of gait with a minimum distance of 10 meters. Results. A total of 48 patients were included in this study: 53.1% males, 46.9% female. Ages ranges from 2 to 18 years with a mean age of 12 years (+/- 2.31). The bone marrow lesion etiology was traumatic (29.16%), congenital (33.33%), neoplasm (8.33%) among others. Injury levels was cervical (31.25%), lumbar (29.16%), non-spinal origin (20.83%), dorsal (16.66%) and sacral (2.08%). Conclusion. The incidence of pediatric spinal cord injury is very small, but poses a great personal and social and care challenge. The review of the literature shows the lack of studies regarding this disease in patients of similar age as well as studies on the gait pattern in these patients(AU)

Aplicación del análisis tridimensional de la marcha en pacientes con síndrome centromedular / Application of gait 3d analysis in patients with central cord syndrome

Introducción. El síndrome centromedular es el más común de las lesiones medulares incompletas y el 87-97% de estos pacientes consiguen una marcha independiente, pero no se han encontrado estudios publicados sobre el análisis de la marcha. El objetivo de este estudio fue analizar las características de la marcha de sujetos con síndrome centromedular y comparar los resultados con un grupo control formado por individuos sanos de características antropométricas similares. Métodos. Se analizó a 12 pacientes con síndrome centromedular y a un grupo control formado por 20 sujetos. Los datos cinemáticos se obtuvieron con un sistema de análisis tridimensional del movimiento. El grupo control caminó a velocidad libre y a velocidad similar a la registrada en los pacientes. Las variables espaciotemporales y cinemáticas se compararon entre los dos grupos. Resultados. La abducción de cadera y la flexión de rodilla en el contacto inicial, así como el mínimo de flexión de rodilla durante la fase de apoyo, fueron mayores en el grupo de pacientes (p<0,05). Sin embargo, los rangos de movimiento de la rodilla y el tobillo en el plano sagital fueron mayores en el grupo control (p<0,05). Conclusiones. El patrón de la marcha de los pacientes mostró una disminución del rango de movimiento en el plano sagital de la rodilla y el tobillo y un incremento de la abducción de la cadera para incrementar la base de sustentación. Estos resultados pueden facilitar la planificación objetiva de los tratamientos encargados de mejorar la marcha en estos pacientes(AU)

Background. Central cord syndrome is the most common incomplete spinal cord injury syndrome and 87-97% of these patients achieve independent walking but no gait analysis studies have been reported. The aim of this study was to analyze the characteristics of the gait in subjects with central cord syndrome and to compare the results with a healthy anthropomorphically matched control group. Methods. Twelve patients and a control group with twenty subjects were analyzed. Kinematic data were obtained using a three-dimensional motion analysis system. The control group walked at a self-selected speed and at a speed similar to the speed previously registered in the patient group. Temporal, spatial variables and kinematic variables were compared between the two groups. Results. Hip abduction and knee flexion at initial contact as well as minimal knee flexion during stance were larger in the patient group (P<.05). However, knee and ankle ranges of motion in the sagittal plane were greater in the control group (P<.05). Conclusions. Knee and ankle range of motion in sagittal plane were reduced and hip abduction was increased to improve stability in patients with central cord syndrome. The results can support objective ways to establish the treatment to recover gait in patients with central cord syndrome(AU)

Voluntary ankle flexor activity and adaptive coactivation gain is decreased by spasticity during subacute spinal cord injury.

Although spasticity has been defined as an increase in velocity-dependent stretch reflexes and muscle hypertonia during passive movement, the measurement of flexor muscle paresis may better characterize the negative impact of this syndrome on residual motor function following incomplete spinal cord injury (iSCI). In this longitudinal study Tibialis Anterior (TA) muscle paresis produced by a loss in maximal voluntary contraction during dorsiflexion and ankle flexor muscle coactivation during ramp-and-hold controlled plantarflexion was measured in ten patients during subacute iSCI. Tibialis Anterior activity was measured at approximately two-week intervals between 3-5 months following iSCI in subjects with or without spasticity, characterized by lower-limb muscle hypertonia and/or involuntary spasms. Following iSCI, maximal voluntary contraction ankle flexor activity was lower than that recorded from healthy subjects, and was further attenuated by the presence of spasticity. Furthermore the initially high percentage value of TA coactivation increased at 75% but not at 25% maximal voluntary torque (MVT), reflected by an increase in TA coactivation gain (75%/25% MVT) from 2.5+/-0.4 to 7.5+/-1.9, well above the control level of 2.9+/-0.2. In contrast contraction-dependent TA coactivation gain decreased from 2.4+/-0.3 to 1.4+/-0.1 during spasticity. In conclusion the adaptive increase in TA coactivation gain observed in this pilot study during subacute iSCI was also sensitive to the presence of spasticity. The successful early diagnosis and treatment of spasticity would be expected to further preserve and promote adaptive motor function during subacute iSCI neurorehabilitation.

Evaluación de la distribución de las presiones de apoyo en la interfaz usuario-cojín para determinar la presión de inflado de los cojines de aire / Evaluation of pressure support in user-cushion interface to determine inflated cushion air

Objetivo: Comprobar si la presión de inflado de los cojines antiescaras de aire en personas con lesión medular es la óptima y determinar su influencia sobre el comportamiento mecánico de los cojines. Material y métodos: Se efectuó el análisis de la distribución de presiones en la interfaz usuario-cojín con una malla de sensores capacitivos en 32 pacientes con lesión medular que disponían de cojines de aire. Se realizó un registro en las condiciones habituales de presión de inflado y otro tras realizar una corrección de ésta una vez identificada la situación óptima de distribución de presiones. Los parámetros analizados fueron los valores de presión máxima, la presión isquiática, la presión media y su desviación estándar y, en cuanto a superficies, la superficie total (Stot), la superficie que soporta una presión mayor de 60mmHg (Stot>60) y su valor porcentual (%Stot>60). Resultados: Los valores de las variables relacionadas con la presión fueron más bajos en los registros efectuados tras la corrección de la presión de inflado y, en las relacionadas con la superficie, la Stot fue más alta en el segundo registro, mientras que tanto Stot>60 y %Stot>60 fueron más bajos. En todos los casos se encontraron diferencias significativas (p<0,05). Conclusión: La diferente presión de inflado de un cojín de aire influye en la distribución de presiones en la interfaz usuario-cojín. La distribución de presiones óptima para un cojín determinado se consigue a un nivel de presión de inflado que ha de ser establecido con unos sistemas de medición objetivos (AU)

Objective: Verify if the inflation pressure of anti-bedsore air cushions in persons with bone marrow injury is optimum and determine its influence on the mechanical behavior of the cushions. Material and methods: The distribution of the user-cushion inferface was analyzed with a capacitive mesh sensor in 32 subjects with bone marrow injury who used air cushions. A recording was made of the usual conditions of inflated pressure and another one after making a correction of it once identified the optimum pressure distribution situation. Parameters analyzed were maximum pressure value (Pmax), ischiatic pressure (IschP), mean pressure (meanP) and standard deviation (SD) and, in regards to surfaces, total surface (totS), surface that supports a pressure of 60 mmHg (totS>60) and percentile value (%totS>60). Results: The values of the variables related with the pressure were lower in the recordings made after correcting for inflated pressure. In those related with surface, the TotS was higher in the second recording while the totS >60 and %totS>60 were lower. There were significant differences in all of the cases (p<0.05). Conclusion: The different inflation pressure of an air cushion influences the pressure distribution of the user-cushion interface. The distribution of the optimum pressures for a certain cushion is achieved at an inflated pressure level that must be established with some objective measurement systems (AU)

Shoulder joint kinetics during wheelchair propulsion on a treadmill at two different speeds in spinal cord injury patients.

STUDY DESIGN: Prospective study using biomechanics patient data. OBJECTIVES: To analyze shoulder joint kinetics while propelling a wheelchair placed on a treadmill and compare shoulder joint net forces and moments when changing the speed of wheelchair propulsion on the treadmill. SETTING: National Hospital for Spinal Cord Injury, Toledo, Spain. METHODS: Sixteen subjects with thoracic spinal cord injury participated. A kinematic analysis system consisting of four camcorders (Kinescan-IBV) and a kinetic device that registered the contact force of the hand on the pushrim (SMART(Wheel)) were used. The wheelchair was propelled at 3 and 4 km h(-1) without any ramp. An inverse dynamic model allowed shoulder joint net forces and moments to be calculated from the contact force of the hand on the pushrim and kinematic data. RESULTS: Increasing propulsion speed increased most of the temporal parameters of propulsion and pushrim kinetics and shoulder joint net forces and moments. Compared with other studies that used an ergometer or dynamometer at the same speed, the magnitude of the shoulder joint net forces and moments elicited by wheelchair propulsion on the treadmill were lower than obtained by wheelchair propulsion on other devices. CONCLUSION: Lower magnitude of shoulder joint forces and moments found on the treadmill may be due to the lower friction compared with the other devices reviewed. Shoulder joint forces and moments depended strongly on the propulsion speed, increasing in magnitude when speed increased from 3 to 4 km h(-1).

Comparative biomechanical gait analysis of patients with central cord syndrome walking with one crutch and two crutches.

BACKGROUND: Ambulatory people with central cord syndrome often require assistive devices. The selection of a suitable assistive device should be based on an objective assessment. Our objective in this study was to determine whether there was any difference in using two crutches over one crutch, considering that these patients have bilateral upper-limb involvement. METHODS: Kinematic gait analysis was conducted in 12 patients with central cord syndrome of more than one year of evolution and functional capacity for walking with one crutch or without crutches. Patients were asked to walk with one crutch and with two crutches at a freely chosen walking speed through a 10-m walkway. Three-dimensional kinematic equipment based on active markers was used to analyze temporospatial and articular parameters (maximum, minimum, and range of motion, ROM, throughout the cycle) FINDINGS: During two-crutch versus one-crutch walking, speed was lower (P=0041), stride time and step time were longer (P=0.004 and P=0.005) and there were fewer strides/minute and steps/minute (P=0.005 and P=0.006). The duration of the single support stance was longer during two-crutch walking (P=0.008). With respect to the articular parameters, both ankle ROMs (dorsi-plantar flexion P=0.003 and pronation-supination P=0.004) were greater with one-crutch walking than with two-crutch walking. INTERPRETATION: In patients with central cord syndrome capable of walking with one crutch or without crutches, walking with two crutches decreases speed, increases stride time and step time and improves stability by increasing single support, and diminishes ankle plantar flexion during swing phase.

Comparative study of pressure distribution at the user-cushion interface with different cushions in a population with spinal cord injury.

BACKGROUND: Few studies have offered comparative information on the mechanical characteristics of different wheelchair seat cushions. The objective of the present study was to compare the benefits of the wheelchair seat cushions most frequently used in a population of patients with spinal cord injury in terms of pressure distribution and contact surface at the user-cushion interface. METHODS: Each one of 48 patients with spinal cord injury was seated in his or her own wheelchair on the four models of cushions analyzed (low-profile air, high-profile air, dual-compartment air, and gel and firm foam), which were presented in randomized order. The pressure distribution readings and support surface area of the user-cushion interface were obtained with a matrix of piezocapacitive sensors. FINDINGS: The dual-compartment air cushion yielded lower readings for all pressure parameters analyzed (P(max), P(mean), P(sd), and P(isch)) than the other three cushion models (P<0.05). The best surface parameter results (S(tot), S>60 and %S>60) also were obtained with the dual-compartment air cushion (P<0.05). INTERPRETATION: In the sample analyzed, the dual-compartment air cushion was the cushion with the best pressure distribution and largest contact surface of the user-cushion interface compared to the other three cushions studied.

Evaluación de la marcha con bastones en pacientes con lesión medular incompleta / Assessment of walking on crutches in patients with incomplete spinal cord injury

Objetivo. Determinar las aportaciones que suponen el empleo de técnicas de análisis biomecánico a la hora de recomendar la marcha con uno o dos bastones en personas con lesión medular incompleta. Material y métodos. Se efectuó el análisis cinemático de la marcha en 12 pacientes con lesión medular incompleta de más de un año de evolución y capacidad funcional para caminar con un bastón. Los pacientes caminaron a velocidad libre en un pasillo de 10 m con uno y con dos bastones. Se utilizó un equipo que permite realizar un análisis cinemático en 3 D basado en marcadores activos. Los parámetros analizados fueron los temporo-espaciales y los articulares (máximos, mínimos y rango articular a lo largo del ciclo). Resultados. Caminando con dos bastones la duración del ciclo es mayor (p = 0,010) y la frecuencia de ciclos/minuto es menor (p = 0,014). Respecto a los parámetros articulares, en la marcha con dos bastones el pico de valor máximo (p = 0,036) y el mínimo de basculación anterior pélvica (p = 0,038), así como el recorrido articular de rotación pélvica (p = 0,006) son mayores, y el valor mínimo de flexión de cadera es menor (p = 0,022). Conclusión. A pesar de la mayor seguridad ofrecida para los lesionados medulares que pueden caminar con un bastón, el hacerlo con dos puede constituir una marcha más costosa. Las técnicas de análisis biomecánico constituyen un elemento de soporte a la hora de recomendar una ayuda técnica para la marcha (AU)

Objective. To determine the differences in gait kinematic parameters of people with incomplete spinal cord injury while walking with one or two crutches. Material and methods. Twelve patients with incomplete spinal cord injury whose injury occurred at least one year ago with functional capacity for walking with one crutch were kinetically analyzed. The patients walked at free rate in a 10 m hallway with one or two crutches. A system was used that allowed for kinematic analysis in 3 D based on active markers. The parameters analyzed were time-space and joint values (maximum, minimum and range of movement during the cycle). Results. When walking with two crutches, the stride time is greater (p = 0.021) and the stride/minute is less (p = 0.014). Regarding joint parameters of walking with two crutches, the maximum value peak (p = 0.036) and the minimum of anterior pelvic tilt (p = 0.038) and the joint range of the pelvic rotation (p = 0.006) are greater and the minimum value of hip flexion is less (p = 0.022). Conclusion. In spite of the greater safety offered for the patients suffering spinal cord injuries, for those who can walk with one crutch, the use of 2 crutches can make walking more difficult. Biomechanical analysis techniques are a supportive element when recommending technical help for walking (AU)