Neuro-Muscular Control of Coordinated and Effective Movements: Revisiting Modular Concepts in the CNS.

Neurophysiologic analysis of motor behavior has become one of the prime research areas in the domain of Physiology and hence it has seen tremendous development integrated research in this field over the years. This short review discusses the broad approaches which favors to understand effective neural control of motor behavior. The focus of this review is to recognize the gradual evolution of basic ideas regarding execution of coordinated and effective movements. The integrated roles of the spinal cord, the cerebellum and the motor cortex in context of voluntary movements have been delineated with citation of important research observations made in the field of motor control. Internet database related to human motor behavior studies were extensively searched to map the chronological development of important research methods and newer findings in this field. The span of the text ranges from the development of the idea of Motor Primitives to Brain-Machine Interfaces. It is observed that several ‘basic’ neural modules are preserved through ontogeny and phylogeny. Different combination of hierarchical modular functioning provides a wide range of plasticity required for coordinated and effective skillful movements.

Anatomy of lumbar interspinous ligaments: attachment, thickness, fibre orientation and biomechanical importance / Anatomía de los ligamentos interespinosos lumbares: inserción, grosor, orientación de las fibras e importancia biomecánica

Literature related to the study of interspinous ligament in the lumbar region is sparse. Very few studies have elucidated the fibre orientation of this ligament at different lumbar levels. Male (19) and female (6) cadavers were dissected to expose the interspinous ligaments beneath all the lumbar vertebrae. Fibre attachments and directions were observed at all lumbar interspinous spaces. Thicknesses of the ligaments were measured at all levels. Interspinous ligament fibres were found to be oriented differently in the lumbar inter-spinous spaces. In the upper spaces the fibres were more horizontal. In the spaces beneath L3 and L4, fibres were curved and extended postero-superiorly. Fibres were thicker in the ligaments at the lower spaces in comparison to the upper ones. The mean thicknesses presented as: Upper (0.22 mm); Middle (0.37 mm) and L5-S1 (0.72 mm). Ligaments in the females were slightly thinner in comparison to the males. Fibres of inter-spinous ligaments were also found to attach to the inner aspects of the supraspinous ligament. Ligaments at L5-S1 junction were relatively vertical and stronger. None of the specimen demonstrated absence or cavitations of these ligaments except in a case with bi-laminar ligament at the L3-L4 level. The anatomy of the interspinous ligaments points to their probable role in graded restricting of acute flexion at the lumbar spine.

La literatura relacionada con el estudio del ligamento interespinoso en la región lumbar es escasa. Pocos estudios han permitido comprender la orientación de las fibras de este ligamento en diferentes niveles lumbares. Fueron disecados cadáveres de 19 hombres 6 y mujeres para exponer los ligamentos interespinosos debajo de las vértebras lumbares. La unión de las fibras y su dirección se observó en todos los espacios interespinosos lumbares. El grosor de los ligamentos se midieron en todos los niveles. Las fibras del ligamento interespinoso se encontró orientada de manera diferente en los espacios lumbares interespinosos. En los dos espacios superiores las fibras eran más horizontales. En los dos espacios centrales (por debajo de L3 y L4) las fibras se curvaban y extendían postero-superiormente. Las fibras eran más gruesas en los ligamentos de los espacios inferiores en comparación con los superiores. La media de espesor presentada por región fue: Alta (0,22 mm), Medio (0,37 mm) y L5-S1 (0,72 mm). Los ligamentos en mujeres fueron ligeramente más delgados. También se observó que las fibras de los ligamentos interespinosas se adhieren a las superficies internas del ligamento supraespinoso. La unión de los ligamentos en L5-S1 eran relativamente más verticales y robustas. En ningún caso se observó ausencia o cavitaciones de los ligamentos, excepto en un caso con ligamento bilaminar a nivel L3-L4. La anatomía de los ligamentos interespinosos señala su probable rol en la restricción de la flexión aguda en la columna lumbar.

Entrapment of the median nerves and brachial arteries in the lower arms bilaterally and additional origin of biceps brachii muscle: case report / Compresión bilateral del nervio mediano y de la arteria braquial en la parte distal del brazo y origen adicional del músculo bíceps braquial: reporte de caso

Neuro-vascular entrapments associated with variations observed in the origins of muscles in the arm are not uncommon. Though additional heads of biceps brachii muscle and extra fibres of brachialis muscles have been demonstrated earlier, bilateral additional heads of the biceps are rarely seen, especially with entrapment of the median nerve and the brachial arteries in both the arms. The present study reports conspicuous heads of the biceps brachii originating extensively from the medial inter-muscular septum, sharing its origin with the brachialis muscle. The extra origins of the muscle formed long musculo-aponeurotic tunnels. The tunnels measured eight centimeters in length extending from the lower arm to the cubital-fossa. Both the median nerve and the brachial arteries passed through the tunnel. The lower aspect of the left tunnel exhibited origins of fibres belonging to the superficial flexors of the forearm. The neuro-vascular structures did not give any branches in the tunnel. Awareness of such variations can aid clinicians in diagnosing and treating such neuropathies and vascular compromise.

No es infrecuente observar atrapamientos neuro-vasculares asociados con variaciones en el origen de los músculos del brazo. A pesar de haberse observado cabezas adicionales del músculo bíceps braquial y fibras extra del músculo braquial raramente estas cabezas adicionales bilaterales han sido causantes de la compresión del nervio mediano y de la arteria braquial. En este trabajo presentamos las cabezas del músculo bíceps braquial originándose en gran parte en el tabique intermuscular medial compartiendo su origen con el músculo braquial. Los orígenes adicionales del músculo forman largos túneles músculo fasciales. Los túneles miden 8 cm de longitud, y se extienden desde la parte inferior del brazo hasta la fosa cubital. Tanto el nervio mediano como la arteria braquial pasan por el túnel. La parte inferior del túnel izquierdo dio origen a fibras pertenecientes al músculo flexor superficial del antebrazo. Las estructuras neurovasculares no otorgaron colaterales en el túnel. El conocimiento de estas variaciones puede ayudar a los clínicos en el diagnóstico y el tratamiento de neuropatías y compromiso vascular.