Selective azetidine and tetrahydropyridine formation via Pd-catalyzed cyclizations of allene-substituted amines and amino acids.

[reaction: see text] By choosing the right substituents either highly functionalized unusual four-membered ring amino acids or the isomeric pipecolic acid derivatives are obtained in enantiomerically pure form. Starting material is a linear allene-containing amino acid that has been resolved via biocatalysis.

Quantitative analysis of surface and percutaneous electromyographic activity in lumbar erector spinae of normal young women.

Bilateral surface and fine-wire electromyographic activity from the erector spinae at the L4-5 interspace was recorded from 10 female subjects during flexion, extension, rotation to right/left, and sidebending to right/left. Fine-wire electrodes demonstrated significant left-right electromyographic differences during terminal flexion. Surface and fine-wire electromyographic recordings demonstrated a symmetric pattern of activity during extension. A symmetric pattern of erector spinae activity was observed during rotation using fine-wire electrodes but not from surface electrodes. Increased electromyographic activity from the contralateral erector spinae was detected by the surface electrodes during sidebending to neutral movements.

The relationship of extraneous movements to lumbar paraspinal muscle activity: implications for EMG biofeedback training applications to low back pain patients.

Within recent years clinicians and researchers have applied paraspinal EMG biofeedback procedures during static and dynamic movement retraining of chronic low back pain patients. Most of these applications make use of surface electromyography, an approach complicated by the fact that the erector spinae muscles are deeply situated. This descriptive study reveals that extraneous movements, such as neck flexion and pelvic rotation, can elicit profound activity from percutaneously placed EMG electrodes while little change is seen at the skin surface. The implications of these observations for the use of EMG feedback to remediate low back pain are discussed.