Effects of isometric elbow flexion on electromyographic spike analysis

The main objective of this research was to examine the relationship between surface electromyographic (SEMG) spike activity and force. The secondary objective was to determine to what extent subcutaneous tissue impacts the high frequency component of the signal, as well as, examining the relationship between measures of SEMG spike shape and their traditional time and frequency analogues. A total of96 participants (46 males and 50 females) ranging in age (18-35 years), generated three 5-second isometric step contractions at each force level of 40, 60, 80, and 100 percent of maximal voluntary contraction (MVC). The presentation of the contractions was balanced across subjects. The right arm of the subject was positioned in the sagittal plane, with the shoulder and elbow flexed to 90 degrees. The elbow rested on a support in a neutral position (mid pronation/mid supination) and placed within a wrist cuff, fastened below the styloid process. The wrist cuff was attached to a load cell (JR3 Inc., Woodland, CA) recording the force produced. Biceps brachii activity was monitored with a pair of Ag/AgCI recording electrodes (Grass F-E9, Astro-Med Inc., West Warwick, RI) placed in a bipolar configuration, with an interelectrode distance (lED) of 2cm distal to the motor point. Data analysis was performed on a I second window of data in the middle of the 5-second contraction. The results indicated that all spike shape measures exhibited significant (p < 0.01) differences as force increase~ from 40 to 100% MVC. The spike shape measures suggest that increased motor unit (MU) recruitment was responsible for increasing force up to 80% MVC. The results suggested that further increases in force relied on MU III synchronization. The results also revealed that the subcutaneous tissue (skin fold thickness) had no relationship (r = 0.02; P > 0.05) with the mean number of peaks per spike (MNPPS), which was the high frequency component of the signal. Mean spike amplitude (MSA) and mean spike frequency (MSF) were highly correlated with their traditional measures root mean square (RMS) and mean power frequency (MPF), respectively (r = 0.99; r = 0.97; P < 0.01).

The War, 8 March 1814 (vol. 2, no. 38, whole no. 90) - Newspaper

Volumes of interest were published between 1812 and 1815 with articles about the War of 1812.

HG 238.80-238.90 Thin Section

Dark brown sediment with clasts ranging from small to medium in size and sub-angular to angular. Contains lineations and grain stacking throughout the sample. Rotation and comet structures can also be seen. Rotation structures can be seen around mainly the sub-angular clasts. Patches of clay can also be seen throughout the sample.

DE #6 260.90-261.0

Coarse grained sediment with clasts ranging from small to medium in size. Clast shape range from sub-angular to sub-rounded. Lineations are present throughout the sample. Edge-to-edge grain crushing, grain stacking, and comet structures can also be seen. Some grains are crushed into one another. Areas of finer sediment can also be seen.

HG 367.80-367.90

Dark grey sediment with clasts that range from small to medium. The clasts are mainly sub-rounded. Lineations are abundant with minor amounts of rotation structures and comet structures. Grain crushing can also be seen throughout the sample.

HG 493.80-493.90

Coarse brown sediment, with clasts ranging from small to large in size. Clast shape ranges from sub-angular to rounded. Lineations and grain crushing are common throughout the sample. It also contains comet structures and a few rotation structures. Many of the larger clasts are also fractured.

HG 28.75-28.90

This sample contains clasts that range from small to large. A few fractured grains can be seen. The grain shape ranges from angular to rounded. Rotation structures can be seen throughout the sample along with some edge-to-edge grain crushing.

HG 64.80-64.90

Dark brown sediment with clasts ranging from small to large in size. The clast shape ranges from angular to sub-rounded. Many of the larger clasts are fractured. Grain crushing is abundant throughout the sample. A few lineations can also be seen throughout the sample.

HG 129.75-129.90

Brown sediment with clasts ranging from small to medium in size. Clast shape ranges from angular to sub-rounded. Rotation structures are abundant in this sample. Edge-to-edge grain crushing, comet structures, and lineations can also be seen in this sample.

Barnes Wines, Limited By-Law No. 90

The By-Law summary states it is "a by-law relating generally to the transaction of the business and affairs of Barnes Wines, Limited". The sub headings of the bill are as follows: Head Office, Corporate Seal, Meetings of Shareholders, Directors, Officers, Notices, Interpretation.