Dry Needling of Myofascial Trigger Points: Quantification of the Biomechanical Response Using a Myotonometer.

Background: Biomechanical stiffness has been linked to risk of injury and found to be a measureable characteristic in musculoskeletal disorders. Specific identification of stiffness may clarify who is most likely to benefit from the trigger point dry needling (TDN). The purpose of this study is to investigate the reliability and concurrent validity of the MyotonPRO® to the criterion of shear wave ultrasound elastography for the measurement of biomechanical stiffness in the infraspinatus, erector spinae, and gastrocnemius of healthy subjects over increasing muscle contraction. Second purpose is to investigate the biomechanical effects of TDN to latent myofascial trigger points (MTrPs) in the infraspinatus, erector spinae, or gastrocnemius. Research Design and Method: The first phase of the study investigated 30 subjects who completed three levels of muscle contraction in standardized test positions for the infraspinatus, erector spinae and gastrocnemius. Biomechanical stiffness measures were collected using shear wave elastography and MyotonPRO®. The second phase of the study investigated 60 new subjects who were categorized into infraspinatus, erector spinae, or gastrocnemius group based on an identified latent MTrP. These subjects underwent TDN while monitoring biomechanical stiffness at baseline, immediately post TDN, and 24 hours later. Analysis: Discriminate ability, reliability, and correlations were calculated for measured stiffness variable across the three conditions of contraction in the first phase of the study. Differences between stiffness at baseline and after TDN were calculated in the second phase of the study. Results: Correlation of the two measurement methods in the three muscle regions was significant and strongest in the gastrocnemius. MyotonPRO reliability was excellent, and demonstrated ability to discriminate between the three levels of muscle contraction. In the second phase, immediate decreased stiffness was observed in the MTrP following TDN treatment. Significant decreased stiffness was found in in the erector spinae and gastrocnemius group who also demonstrated a localized twitch response during TDN. Stiffness returned to near baseline values after 24 hours. Discussion: The MyotonPRO® stiffness measurement was found to be reliable and discriminate across predefined muscle contraction intensities. TDN may cause an immediate change in stiffness but this change was not observed at 24 hours. It is not known whether these effects are present in a symptomatic population or related to improvements in other clinical outcomes. Future studies are necessary to determine if a decrease in biomechanical stiffness is an indication of patient improvement in pain and function

Nasal Resonance in Speech Sounds

A special phonophotographic camera makes possible the photographing of nasal resonance together with a time line. On the basis of these photographs, it is shown that each vowel has a specific nasal element in its resonance, the duration of which varies directly with the closeness of the vowel. It is shown further that the duration of nasal resonance in vowels phonated by individuals with badly nasal voices is greater than in vowels phonated by those having superior voices

Labor Arbitration and Title VII of the Civil Rights Act of 1964

Title VII of the Civil Rights Act of 1964 sets forth certain broad prohibitions of discrimination against individuals on the basis of race, color, religion, sex or national origin. Although Title VII deals with discrimination by employers, employment agencies and labor unions, this comment will concern itself only with the employer, and, more specifically, with one particular problem arising from an employer employee relationship

Recent Decisions

Comments on recent decisions by Lawrence J. Gallick, Joseph P. Summers, Thomas J. Kelly, Louis P. Pfeiler, and Hurley D. Smith

Cyclic ADP-ribose metabolism in rat kidney: High capacity for synthesis in glomeruli

Cyclic ADP-ribose metabolism in rat kidney: High capacity for synthesis in glomeruli. Recent discovery of cyclic ADP-ribose (cADPR) as an agent that triggers Ca2+ release from intracellular stores, through ryanodine receptor channel, is an important new development in the investigation of intracellular signaling mechanisms. We determined the capacity of kidney and its components for synthesis of cADPR from β-NAD, that is catalyzed by enzyme ADP-ribosyl cyclase, and enzymatic inactivation that is catalyzed by cADPR-glycohydrolase. Little or no activity of ADP-ribosyl cyclase was found in extracts from the whole rat kidney, renal cortex, outer and inner medulla. On the other hand, incubation of β-NAD with similar extracts from rat liver, spleen, heart, and brain resulted in biosynthesis of cADPR. In addition, extracts from suspension of proximal tubules or microdissected proximal convoluted tubules virtually lacked ADP-ribosyl cyclase activity. In sharp contrast to proximal tubules and cortex, extracts from glomeruli had high ADP-ribosyl cyclase activity, similar to that found in non-renal tissues. Authenticity of cADPR biosynthesized in glomeruli was documented by several criteria such as HPLC analysis, effect of inhibitors and homologous desensitization of Ca2+-release bioassay. On the other hand, the activity of cADPR-glycohydrolase was similar in extracts from glomeruli and in extracts from kidney cortex. Mesangial cells and vascular smooth muscle cells grown in primary culture displayed considerable ADPR-ribose cyclase activity. Our results show that extracts from glomeruli, unlike extracts from renal tissue zones and proximal tubules, have a singularly high capacity for synthesis of cADPR. We surmise that cADPR-triggered Ca2+-releasing system can serve as an intracellular signaling pathway that may be operant in regulations of glomerular cell functions

Age-related differences in conditioned pain modulation of sensitizing and desensitizing trends during response dependent stimulation

The current study evaluated age differences in conditioned pain modulation using a test stimulus that provided the opportunity to evaluate changes in heat pain sensitivity, sensitization, and desensitization within the same paradigm. During this psychophysical test, pain intensity clamping uses REsponse Dependent STIMulation (REDSTIM) methodology to automatically adjust stimulus intensity to maintain a desired pain rating set-point. Specifically, stimulus intensity increases until a pre-defined pain rating (the setpoint) is exceeded, and then decreases until pain ratings fall below the setpoint, with continued increases and decreases dictated by ratings. The subjects are blinded in terms of the setpoint and stimulus intensities. Younger and older subjects completed two test sessions of two REDSTIM trials, with presentation of conditioning cold stimulation between the trials of one session but not the other. The results indicated that conditioning cold stimulation similarly decreased the overall sensitivity of younger and older subjects, as measured by the average temperature that maintained a setpoint rating of 20 (on a scale of 0-100). The conditioning stimulus also significantly enhanced sensitization following ascending stimulus progressions and desensitization following descending stimulus progressions in older subjects relative to younger subjects. Thus, older subjects experienced greater swings in sensitivity in response to varying levels of painful stimulation. These results are discussed in terms of control over pain intensity by descending central modulatory systems. These findings potentially shed new light on the central control over descending inhibition and facilitation of pain