Intramuscular haemodynamic responses to different durations of sustained extension in normal human masseter
Introduction
Stretching, shortening (with or without contraction) and isometric contraction are biomechanical factors that might influence haemodynamic measurements in jaw muscles. With the exception of a recent study by Kim et al. (1999), the effect that these factors might have on muscle blood volume has not been evaluated systematically. Such information would be unimportant if all research on blood flow was on resting (neither stretched nor shortened) muscles. Of course this is not the case and several recent studies on muscle blood flow involve stretching and/or contraction of the muscle studied. For example, Larsson et al. (1994) measured the microcirculation in the upper portion of the trapezius in 25 patients with pain persisting after a soft-tissue injury of the neck. They reported that the ability to increase muscle blood flow during arm elevation was impaired on the painful side in the patients with unilateral pain. Delcanho et al. (1996) demonstrated less perfusion of the masseter muscle immediately after maximal isometric contraction in patients with chronically painful masticatory muscles than in asymptomatic individuals. Tsukiyama et al. (1999) looked at the combined effects of cold pressor stimuli and muscle contraction on perfusion in the masseter. In all of these studies, some degree of stretching, shortening or contraction occurred.
In the one study in which contraction was evaluated systematically, Kim et al. (1999) describe the influence that various degrees of isometric muscle activation can have on intramuscular haemodynamics (specifically blood-volume recordings) in the masseter and temporalis. What is missing now is research on the influence that various amounts of stretching might have on jaw muscle haemodynamics (e.g. blood volume). Intramuscular blood flow has been measured during stretching of other muscles in several animal studies, but not in humans. Those animal studies revealed that intramuscular blood flow is impeded by stretching (Gimlette and Nasrallah, 1969, Wisnes and Kirkebø, 1976, Supinski et al., 1986). Gimlette and Nasrallah (1969) measured blood flow in a skeletal muscle (dog gastrocnemius) during and after stretching, using both 133Xenon clearance and venous occlusion plethysmography, and observed a decrease of flow during stretching with both methods. However, although by plethysmography they found a small increase in blood flow after the stretching, the decreased rate of 133Xenon clearance did not return to baseline. These studies are helpful, but in vivo human studies on specific muscle groups are needed.
We now elected to assess changes in intramuscular blood volume in the human masseter under conditions of maximum stretch. To determine whether any observed haemodynamic changes were dependent on the conditions of the stretch itself or on its duration, we also used varying periods of muscle extension. The null hypothesis was that there is no difference in the blood volume of the masseter before, during and after maximum extension of different durations.
Section snippets
Participants
Ten healthy non-smoking males (age 24.3±0.8 years; range 23–25 yr) without masticatory muscle pain participated. They were selected from students of the Okayama University Dental School. After a screening questionnaire those individuals deemed potentially suitable were questioned verbally about their medical and dental history to ensure they could safely participate in the experiment and provide unbiased data. They were then examined intraorally and extraorally to ensure that the selection
Haemoglobin
Fig. 1 shows changes in haemoglobin concentration before, during and after muscle extension. In all the experimental trials, the mean normalized haemoglobin decreased during the extension and then increased beyond baseline after it. However, these incremental changes were over (back to baseline) within 1 min after extension. The two-way, repeated-measures ANOVA for the mean maximal change in normalized haemoglobin before, during and after extension revealed a significant main effect for time
Discussion
In this study, a non-invasive method (near-infrared spectroscopy) was used to monitor haemodynamic changes in the masseter muscle. Its non-invasive nature makes it superior to earlier methods for measuring muscle blood volume, as the probe produces no tissue damage. We are confident that the blood-volume data collected represent the haemodynamic changes in the region of interest in the masseter, because the technique of near-infrared spectroscopy for measuring muscle haemodynamics has been
References (16)
- et al.
Haemodynamic responses in chronically painful, human trapezius muscle to cold pressor stimulation
Arch. Oral Biol.
(1999) - et al.
Haemodynamic changes induced by submaximal isometric contraction in painful and non-painful human masseter using near infrared spectroscopy
Arch. Oral Biol.
(1996) - et al.
Haemodynamic changes in human masseter and temporalis muscles induced by different levels of isometric contraction
Arch. Oral Biol.
(1999) - et al.
Chronic pain after soft-tissue injury of the cervical spine: muscle blood flow and electromyography at static loads and fatigue
Pain
(1994) - et al.
Cold pressor stimulus temperature and resting masseter muscle haemodynamics in normal human subjects
Arch. Oral Biol.
(1998) - et al.
Effect of intravenous infusion of an α-adrenergic blocking agent on the haemodynamic changes in human masseter muscle induced by cold pressor stimulation
Arch. Oral Biol.
(1999) - et al.
Effect of intravenous infusion of a β-adrenergic blocking agent on the haemodynamic changes in human masseter muscle induced by cold pressor stimulation
Arch. Oral Biol.
(1999) - et al.
Recovery from exercise induced desaturation in the quadriceps muscles of elite competitive rowers,
Am. J. Physiol.
(1992)
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