Technical NoteComparison Between Neck and Shoulder Stiffness Determined by Shear Wave Ultrasound Elastography and a Muscle Hardness Meter
Introduction
Neck and shoulder pain is a common complaint in the general population, and one of its initial symptoms is neck and shoulder stiffness (Ming et al. 2004). Neck and shoulder pain has a significant detrimental impact on health-related quality of life and physical functioning (Hill et al., 2010, Luo et al., 2004) and appears to relate to other disorders, such as headache and arm numbness or pain (Whiteley et al., 1993, Yeung et al., 2004). The objective evaluation of neck and shoulder stiffness is thus essential to find individuals who are at risk of neck and shoulder pain and to prevent neck and shoulder pain. A muscle hardness meter is often used to assess neck and shoulder stiffness (Arokoski et al., 2005, Ashina et al., 1999, Horikawa, 2001, Matsubara et al., 2011). In view of the powerful and potentially obfuscating influence of the hardness of subcutaneous adipose tissue and superficial muscles, however, there are doubts about whether this instrument is useful in evaluating the hardness of deep muscles.
Meanwhile, muscle elasticity has recently been quantified using shear wave ultrasound elastography (Akagi and Takahashi, 2013, Akagi and Takahashi, 2014, Akagi et al., 2014, Chernak et al., 2013, Maher et al., 2013, Nakamura et al., 2014). Kuo et al. (2013) determined neck muscle stiffness using shear wave ultrasound elastography and found that patients with chronic neck pain symptoms had a significantly stiffer trapezius muscle. However, they did not use the muscle hardness meter, and it is not clear whether the muscle hardness meter can measure neck and shoulder stiffness conveniently. In this study, therefore, we evaluated neck and shoulder stiffness using shear wave ultrasound elastography and the muscle hardness meter and compared the results. Given that the hardness of the masseter muscle assessed by ultrasound elastography was correlated with that determined with a muscle hardness meter (Ariji et al. 2013), we hypothesized that neck and shoulder stiffness evaluated by shear wave ultrasound elastography would correspond to that evaluated with a muscle hardness meter to some extent. In addition, individuals' subjective neck and shoulder stiffness was also determined to verify correspondence between objective and subjective neck and shoulder stiffness.
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Patients
After providing written informed consent, a total of 24 men (n = 12; age, 21 ± 1 y; body height, 172 ± 5 cm; body mass, 60 ± 6 kg; presented as mean ± standard deviation [SD]) and women (n = 12; age, 22 ± 1 y; body height, 159 ± 5 cm; body mass, 54 ± 5 kg) (all expressed as the mean ± standard deviation [SD]) without any orthopedic abnormalities of the neck and shoulders participated in the present study. The patients were either sedentary or physically active. The study protocol was approved
Results and Discussion
Descriptive data on the indices of muscle hardness are summarized in Table 1. None of the correlation coefficients between the values of muscle hardness indices determined with the muscle hardness meter and those determined with shear wave ultrasound elastography were significant (R1: r = 0.179, p = 0.404; R2: r = 0.208, p = 0.329; R3: r = 0.134, p = 0.532; L1: r = 0.085, p = 0.694; L2: r = 0.197, p = 0.357; L3: r = 0.330, p = 0.115). This result disproved the hypothesis that neck and shoulder
Acknowledgments
This study was partly supported by MEXT/JSPS KAKENHI Grant 24700689 (Grant-in-Aid for Young Scientists B).
References (20)
Effect of visual display terminal height on the trapezius muscle hardness: Quantitative evaluation by a newly developed muscle hardness meter
Appl Ergon
(2001)- et al.
Neck muscle stiffness quantified by sonoelastography is correlated with body mass index and chronic neck pain symptoms
Ultrasound Med Biol
(2013) - et al.
Relationships of clinical, psychologic, and individual factors with the functional status of neck pain patients
Value Health
(2004) - et al.
Quantification of dry needling and posture effects on myofascial trigger points using ultrasound shear-wave elastography
Arch Phys Med Rehabil
(2013) - et al.
Neck and shoulder pain related to computer use
Pathophysiology
(2004) - et al.
Acute effects of static stretching on muscle hardness of the medial gastrocnemius muscle belly in humans: An ultrasonic shear-wave elastography study
Ultrasound Med Biol
(2014) - et al.
Density and hydration of fresh and fixed human skeletal muscle
J Biomech
(2005) - et al.
Acute effect of static stretching on hardness of the gastrocnemius muscle
Med Sci Sports Exerc
(2013) - et al.
Effect of a 5-week static stretching program on hardness of the gastrocnemius muscle
Scand J Med Sci Sports
(2014) - et al.
Muscle hardness of the triceps brachii before and after a resistance exercise session: A shear wave ultrasound elastography study
Acta Radiol
(2014)