A manual of diseases of the nervous system . being carried so far back that avertical line from the scapula falls an inch or more behind the is due, not to the weakness of the trunk muscles, but to that of theextensors of the hip, in consequence of which the pelvis is inclinedforwards, carrying with it the lower lumbar vertebra ; hence the upperpart of the trunk has to be held far back to keep the centre of gravityof the body over the feet. The proof of this mechanism is that whenthe patient sits, and the pelvis is supported on the ischial tuberosities,the lordosis disappears. It is,
A manual of diseases of the nervous system . being carried so far back that avertical line from the scapula falls an inch or more behind the is due, not to the weakness of the trunk muscles, but to that of theextensors of the hip, in consequence of which the pelvis is inclinedforwards, carrying with it the lower lumbar vertebra ; hence the upperpart of the trunk has to be held far back to keep the centre of gravityof the body over the feet. The proof of this mechanism is that whenthe patient sits, and the pelvis is supported on the ischial tuberosities,the lordosis disappears. It is, indeed, replaced by an opposite curve,in which the back becomes convex, clearly due to the weakness of itsextensor muscles. This curve may become very great, as in the caseshown in Fig. 153. The weakness of the spinal muscles also permitsthe occurrence of lateral curvature (Fig. 152), influenced, in its PSEUDO-HYPERTEOPHIC MUSCULAR PARALYSIS. 513 direction, by the habitual posture aud the preponderance of weaknesson one side or the Fig. 153.—Lad, aged fifteen; late stage; wasting ofthighs; inability to sit upright in consequence oftlie weakness of the spinal muscles. The electric irritability of the muscles is only altered when distinctweakness or wasting has set in, wlien it is lowered alike to faradismand voltaism. There is never any trace of degenerative reaction. The knee-jerk may be at first normal, but as the extensors of theknee become feeble, it is alwajs lessened and gradually disappears. Itis never excessive, and in all advanced cases it is lost. Sensation isunaffected, aud so also are the sphincters in the vast majority of rarely there has been, towards the end, a slight difficulty in theretention or expulsion of urine, to be regarded, perhaps, rather as acomplication than as an effect of the disease. All other functions ofthe nervous system are commonly normal, including those of thesympathetic. The mental development of the subjects of this di
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnervoussystem, bookye
