_Lumbosacral Plexus_: This plexus, derived from the anterior primary divisions of the lumbar, sacral, and coccygeal nerves, supplies the muscles and integument of the lower extremity, taking with it axons derived from the sympathetic by the lumbar ganglia to supply the blood-vessels, perspiratory glands and sebaceous glands of this region. The latter are responsive to adjustments of the first or second lumbar vertebrae. _Hip-Joint_: Third and fourth lumbar nerves by femoral and obturator or accessory obturator nerves and fifth lumbar or first sacral by the nerve to the quadratus femoris or the great sciatic. Fourth lumbar seems the most potent connection and is usually adjusted for hip-joint disease. _Psoas Magnus Muscles_: Anterior branches of the second and third lumbar nerves. _Anterior Thigh Muscles_: Supplied mostly through the femoral nerve from the second and third lumbar nerves. _Internal Thigh Muscles_: Second and third lumbar nerves (chiefly but not wholly) through the obturator, accessory obturator and femoral nerves. _Gluteus Maximus_: From the fifth lumbar and first and second sacral nerves through the inferior gluteal branch of the sacral plexus. _Obturator Externus_: Second, third, and fourth lumbar nerves through the obturator nerve. _Posterior Thigh Muscles_: Fourth and fifth lumbar and sacral nerves through the great sciatic. _Great Sciatic Nerve_: This great nerve, direct continuation of the sacral plexus, arises from the fourth and fifth lumbar and first three or four sacral nerves and is widely distributed to muscles and integument of the lower extremity. Sciatica, or sciatic rheumatism, is most commonly relieved by adjustment of fourth or fifth lumbar vertebra; but there is a condition commonly diagnosed as sciatica which is really a sciatic neuritis and due to vasomotor disturbance affecting the blood-supply to the nerve trunk. This responds to adjustment of first or second lumbar because the amyelinic fibres which control these blood-vessels are derived from lumbar ganglia of the sympathetic. _Anterior Leg Muscles_: Fourth and fifth lumbar and first sacral nerves through the anterior tibial. _Posterior Leg Region_: Fourth and fifth lumbar and first and second sacral through the internal popliteal and posterior tibial. _Knee-Joint_: This joint receives branches from the great sciatic through both internal and external popliteal, and from the femoral and obturator. It is therefore connected with the lower lumbar and sacrum and with the second lumbar. The latter connection seems oftenest involved in knee joint inflammations. _Foot_: Fourth and fifth lumbar and sacral nerves through the great sciatic and its branches. _Sensor Areas of Lower Extremity_: In general, any given cutaneous area receives sensor branches from the nerve which supplies the subjacent muscle area. For accurate diagnostic purposes a good chart of sensor distribution may be consulted. DISEASES AND ADJUSTMENTS