RESUMEN
BACKGROUND: Forward head posture (FHP) is a forward positioning of the head relative to the trunk in the sagittal plane. This posture is one of the most prevalent poor postures in patients with head and neck pain. Rehabilitative Ultrasound Imaging (RUSI) is a reliable method to objectively evaluate muscle thickness and function. OBJECTIVE: To compare thickness of cervical muscles that control both head and neck posture between asymptomatic women with and without FHP. METHODS: Seventy asymptomatic women aged between 20 and 40 years, with and without FHP (35 in each group), participated in the study. The thickness of the cervical muscles (rectus capitis posterior - RCP, oblique capitis superior - OCS, semispinalis capitis - SSC, sternocleidomastoid - SCM, and longus coli - LCo) was measured using RUSI and the data was compared between the two groups. RESULTS: The comparison of cervical muscle thickness between women with and without FHP revealed significant difference only with regard to the muscle thickness of the SCM muscle (mean difference: 0.7mm, 95% confidence interval of the difference: 0.14, 1.26mm, p value: 0.014). The thickness of this muscle was greater in women with FHP. CONCLUSION: Tonic contraction of the SCM muscle can lead to greater thickness of this muscle in subjects with FHP.
Asunto(s)
Cabeza/fisiología , Músculos del Cuello/fisiología , Dolor de Cuello/fisiopatología , Postura/fisiología , Femenino , Humanos , Rango del Movimiento ArticularRESUMEN
Aim: This study evaluated the effect of varying the powder/liquid (P/L) ratio on the shear bond to dentin (SBS) and flexural strength (FS) of glass ionomer cements (GIC)s. Methods: Three types of GICs (Fuji II, Fuji II LCi and Fuji IX GP) were mixed using the following P/L ratios: 20% lower than the manufacturer's ratio, manufacturer's ratio, 20% higher than the manufacturer's ratio (9 groups). SBS (MPa) was evaluated and the mode of failure checked under stereomicroscope. FS (MPa), of the specimens (25×2×2mm) assessed using a universal testing machine at a crosshead speed of 1 mm/min. The data were subjected to two-way ANOVA and Tukey's test for analysis (p< 0.05). Results: The highest SBS and FS (MPa) obtained for Fuji II, Fuji II LCi and Fuji IX were 6.12±2.11 and 16.96±2.73; 11.60±3.19 and 49.58±8.75; 7.39±2.77 and 20.32±2.09, respectively. The interaction between materials and P/L ratios had no significant effect on the properties tested in this study. Fuji II LCi exhibited significantly higher SBS and FS than the other two GICs in all P/L ratios. Conclusions: No significant differences were observed between Fuji II and Fuji IX. Twenty percent variation in P/L ratio had no significant effect on SBS and FS of GICs.