To compare ultrasonography (USG) parameters of deep abdominal muscles (transversus abdominis-TrA, internal obliques-IO) between women with and without chronic neck pain (CNP).
Women with CNP (n=18; mean-age=37.7 years; mean-BMI=22.7 kg/m2) and asymptomatic individuals (n=18; mean-age=36.1 years; mean-BMI=21.8 kg/m2) participated in the study. The activation of the deep neck flexors (ADNF) was measured using cranio-cervical flexion test. Muscle thickness, changes in thickness (ΔT), and contraction ratio (CR) of deep abdominal muscles were evaluated by ultrasonography device in two conditions: standard-protocol and during ADNF. For each condition, ultrasound image of abdominal muscles was captured at rest and during abdominal draw-in manoeuvre (ADIM).
Comparative statistics revealed no significant difference between groups regarding ultrasonography parameters in the standard-protocol (p>0.05). Besides, there was no difference in the CR of TrA and IO between groups in the two conditions. However, women with CNP showed less muscle thickness of TrAADIM during ADNF than the asymptomatic participants (p<0.05). The CNP group also had decreased ΔT of TrA(ADIM-rest) during ADNF compared to the asymptomatic group (p<0.05).
The ultrasonography parameters of TrA suggest that motor control in the lumbar region is altered in women with CNP. The combination of cervical stabilization exercises with ADIM can be a novel strategy in the treatment of CNP.

Research investigating differences in gluteus medius muscle activity in those with and without chronic nonspecific low back pain is both limited and conflicting. Additionally, in these populations the relationship between gluteus medius muscle activity, foot type, and transversus abdominis muscle thickness is unclear.
We aimed to investigate gluteus medius muscle activity during gait in those with and without chronic nonspecific low back pain. Secondarily, we aimed to explore the association between gluteus medius muscle activity, foot type, and transversus abdominis muscle thickness within groups.
This case control study recruited 30 people with and 30 people without chronic nonspecific low back pain and matched participants by age (±5 years), sex, and body mass index (±2 BMI units). Gluteus medius muscle activity was measured with surface electromyography during walking gait, with foot type and transversus abdominis muscle thickness measured with the Foot Posture Index and ultrasound respectively. The Mann-Whitney U test was used to investigate differences in gluteus medius muscle activity between groups. Spearman rank order correlation was performed to explore the association between gluteus medius muscle activity, foot type, and transversus abdominis thickness within each group. A linear regression was used to analyse significant correlations (P < 0.05).
We found no significant differences in gluteus medius muscle activity between groups. However, there was a moderate correlation between the Foot Posture Index score and gluteus medius peak amplitude (P = 0.04) for those with mild to moderate chronic nonspecific low back pain.
Clinicians should be aware that patients with mild to moderate chronic nonspecific low back pain may not demonstrate significant differences in gluteus medius muscle activity compared to those without back pain. Additionally, higher peak gluteus medius muscle activity is likely to occur in people with mild to moderate chronic nonspecific low back pain and planus feet.

BACKGROUND: An impact of regular physical activity (RPA) on the abdominal muscles may be significant when comparing various symptomatic groups. However, there is lack comprehensive information in this field. The objective of this study was to assess the lateral abdominal wall at rest and during abdominal drawing-in manoeuvre in adolescent physically active girls in different body positions.
METHODS: One hundred and forty-four female students, 13-17 years of age, participated in the study. Participants were divided into 2 groups based on a physical activity (PA) statement. Measurements of the thickness of the abdominal muscles at rest and during abdominal drawing-in manoeuvre were made in the supine and standing positions by ultrasound imaging.
RESULTS: Compared to the control group, activities of the obliquus internus and transversus abdominis muscles were higher in the regular PA group by 8.9% (95%CI: 3.1-14.7) and 36% (95%CI: 19.1-47.5), respectively. In the RPA group, the transversus abdominis preferential activation ratio was greater by 0.03 (95%CI: 0.01-0.04), and the contraction ratio was greater by a mean value of 0.35 (95%CI: 0.18-0.46).
CONCLUSIONS: RPA does not have any effect on the resting thickness of the abdominal muscles in the supine and standing positions. Girls performing RPA have a greater ability to perform an independent activation and greater contractions of the transversus abdominis.

BACKGROUND: Low back pain (LBP) is a common complaint amongst adolescent athletes. While different studies have shown association between LBP and trunk muscle thickness in the general population, few articles have studied it in adolescent athletes.
OBJECTIVE: The aim of this study is to compare lateral abdominal muscle thickness and function, and cross sectional area (CSA) of lumbar multifidus (LM) in adolescent soccer players with and without LBP.
METHODS: In total, 28 adolescent soccer players with and without LBP, from the premier league participated in this study. The thickness of external oblique, internal oblique and transversus abdominis and the CSA of the LM muscles at L4 level on both sides were measured at rest and contraction via ultrasound imaging (USI). In addition, leg length discrepancy, hamstring flexibility, active lumbar forward flexion, and isometric muscle endurance of trunk extensors were measured in both groups. (study design/setting: case control study).
RESULTS: The mean (SD) age in LBP group and non-LBP group were 14.0 (1.1) and 14.1 (0.9) years, respectively. There was no significant difference in baseline characteristics of participants between groups. Findings showed no significant difference between LBP and non-LBP groups comparing all measured variables.
CONCLUSIONS: The data obtained support that there is not a correlation between abdominal muscle thickness and CSA of the lumbar multifidi and LBP in adolescent soccer players. These findings suggest that other factors rather than the thickness of deep trunk muscles may play a more significant role in the etiology of LBP in adolescent soccer players.