Michelle E. Cohen

A test of the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury

This study was designed to test the 1992 International Standards for Neurological and Functional Classification of Spinal Cord Injury. One hundred and six professionals in the field of spinal cord injury attending an instructional course at the 1994 ASIA Meeting participated in the test. Participants completed a pretest and posttest in which they classified two patients who had a spinal cord injury (one with complete tetraplegia and one with incomplete paraplegia) by sensory and motor levels, zone of partial preservation (ZPP), ASIA Impairment Scale and completeness of injury. Between tests, three members of the ASIA Standards Executive Committee gave presentations on the neurological assessment, scoring, scaling and classification of spinal cord injury and a video of the actual examinations of the two cases was viewed. Percent ‘correct’ (as defined by the ASIA Standards Committee) was calculated for sensory and motor levels, ZPP, ASIA Impairment and completeness. Overall, the analyses showed that participants had very little difficulty in correctly classifying the patient with complete tetraplegia. Pretests scores ranged from 72% (left motor level) to 96% (complete injury), posttest scores from 73% (left motor level) to 100% correct (complete injury). For the patient with incomplete paraplegia (Case 2), scores were considerably lower. Pretest scores ranged from 16% (right motor level) to 95% correct (incomplete injury); posttest scores from 21% (right motor level) to 97% correct (incomplete injury). The results showed that further revisions of the 1992 Standards and more training is needed to ensure accurate classification of spinal cord injury.

Strength post-spinal cord injury: myometer vs manual muscle test

This study was designed to compare changes in strength after spinal cord injury (SCI) with the use of a hand held myometer to the manual muscle test (MMT). Eighty-eight C4-C8 Frankel A-D tetraplegie subjects were tested at various times up to 2 years post-SCI. Elbow flexor strength on successive examinations were grouped according to their early and later MMT scores (3.5 with no change in MMT, 3.5 to 4.0, and 3.5 to 4.5; 4.0 with no change in MMT, 4.0 to 4.5, and 4.0 to 5.0; 4.5 with no change in MMT, and 4.5 to 5.0). For each group, later myometric measurements (MYO) were expressed as percents of their earlier MYO and were anlayzed using paired Students t-tests. Later MYO were 116, 205, 232% (P>0.05, P<0.002, P<0.05) of their earlier MYO for groups 3.5 with no change in the MMT, 3.5 to 4.0, and 3.5 to 4.5 respectively. Later MYO were 140, 139, 191% (P<0.05, P<0.02, P<0.0001) of their earlier MYO for groups 4.0 with no change in MMT, 4.0 to 4.5, and 4.0 to 5.0 respectively. Later MYO were 127 and 126% (P<0.01, P<0.02) of their earlier MYO for groups 4.5 with no change in MMT and 4.5 to 5.0 respectively. In conclusion the hand held myometer detected changes in muscle strength not detected by the MMT.

Elbow extension using anterior deltoids and upper pectorals in spinal cord-injured subjects

OBJECTIVE Surface electromyography was used to identify muscles active in isometric elbow extension in spinal cord-injured (SCI) patients. DESIGN Tetraplegic subjects participated in this cohort study aimed at identifying some of the muscles that are active during isometric elbow extension. SETTING Regional Spinal Cord Injury (SCI) Center. PATIENTS The patients had to have a C6 motor level on the right side (wrist extensor > or = 3/5) with 0/5 or 1/5 elbow extensor muscle power. Of 32 patients who could be contacted by telephone, 6 eventually were able to make it to the SCI center for testing. MEASUREMENTS The patients performed a series of isometric elbow extension contractions of 25%, 50%, and 75% of maximum voluntary contraction (MVC) as measured by a force transducer. Surface electromyography (EMG) of the right elbow extensor, anterior deltoid, and upper pectoral muscles was measured using the root mean square (rms) of the amplitude of the motor unit activity as the parameter of muscle activity. Statistical analyses were performed using a repeated analysis of variance (ANOVA) with Tukey post-hoc HSD for each percentage of MVC. RESULTS For each muscle tested, there was significantly (p < 0.05) greater rms activity for each percentage of MVC except between 50% and 75% MVC of the elbow extensor muscle. However, the elbow extensor muscle had minimal EMG activity when compared with the amplitude of the rms activity of the anterior deltoid and upper pectoral muscles for each percentage of MVC. CONCLUSION The results of the study suggest that the anterior deltoid and the upper pectoral muscles exert an isometric elbow extension force for C6 quadriplegic patients.

Use of shoulder flexors to achieve isometric elbow extension in C6 tetraplegic patients during weight shift

The anterior deltoid muscle has been found to be active during elbow extension in normal volunteers and in C6 tetraplegic patients lacking a functional triceps. Using surface electromyography (EMG) on normal volunteers and on patients with spinal cord injury (SCI) at the C6 motor level, we evaluated whether the anterior deltoid and biceps brachii muscles are active during closed chain elbow extension in a simulated weight shift position. Thirteen normal volunteers performed isometric contractions at 5 submaximal levels of force ranging from 4 – 25 kg. Six SCI patients performed isometric contractions at force levels of 20%, 40%, 60%, 80% and 100% maximum voluntary contraction (MVC). Surface EMG over the right biceps, triceps, and anterior deltoid muscles was recorded for each participant and the root mean square (rms) electromyographic activity level for each muscle was determined at each level of force. Statistical analyses using repeated ANOVA with Tukey HSD post-hoc tests were performed for each level of force. The results indicated increasing rms activity of the triceps and anterior deltoid muscles with increasing force in normal volunteers to a significant degree (P<0.05). SCI patients showed significant increasing activity of the anterior deltoid with increasing force, but showed minimal triceps rms activity. In both groups, the biceps showed minimal rms activity. SCI patients exhibited significantly greater rms activity of the anterior deltoid at low force compared with normal volunteers. The results suggest that the anterior deltoid aids in isometric elbow extension during a simulated weight shift maneuver.