A Comparison between Core Stability Exercises and Muscle Thickness Using Two Different Activation Maneuvers

Core stability training is crucial for competitive athletes, individuals who want to improve their health and physical performance, and those undergoing clinical rehabilitation. This study compared the ultrasound (US) muscle thickness of the abdominals and lumbar multifidus (LM) muscles between seven popular trunk stability exercises performed using hollowing and bracing maneuvers. Forty-four healthy young adults, aged between 21 and 32 years, performed a plank, bird dog, beast crawl, dead bug, Pilates tap, bridge, and side planks using the bracing and the hollowing maneuver. The thickness of the transversus abdominis (TrA), internal oblique (IO), and LM muscles was measured simultaneously using two ultrasound machines. Analysis of variance designs indicated that during hollowing, the bird dog and side plank exercises resulted in the greatest increase in the muscle's relative thickness overall. The relative thickness of all muscles was significantly greater (p < 0.001) during hollowing (22.7 ± 7.80 to 106 ± 24.5% of rest) compared to bracing (18.7 ± 7.40 to 87.1 ± 20.9% of rest). The TrA showed the greatest increase in thickness (p < 0.001) compared to the IO and LM. Additionally, the IO had a greater increase in thickness (p < 0.001) than the LM. In conclusion, our findings indicate that the bird dog and side plank exercises, when performed with hollowing, showed the most significant total muscle thickness increase. Notably, the hollowing maneuver enhances the thickness of the TrA, IO, and LM muscles more than the bracing maneuver. This contributes to the discussion on optimal strategies for dynamic core stabilization.

Characteristics and Influencing Factors on the Hollowing of Traditional Villages-Taking 2645 Villages from the Chinese Traditional Village Catalogue (Batch 5) as an Example

With the rapid development of urbanization and modernization, the population of traditional villages migrates into surrounding areas, causing the hollowing of traditional villages. The disintegration of China's traditional village means the loss of historical memory and cultural characteristics of ethnic regions, seriously endangering the country's cultural heritage. To better understand the hollowing phenomenon, this study analyzed 2645 villages from the Chinese traditional village catalogue (Batch 5) and evaluated different village attributes, including location, household registration, permanent population, number of traditional buildings, cultural relics, historical buildings, and non-heritage representative projects. We constructed an evaluation index system and used the entropy weight method, comprehensive evaluation method, and correlation analysis method to quantitatively assess the characteristics and influencing factors of hollowing among traditional Chinese villages. The main results are as follows: ① The hollowing index was above 0.5; most traditional villages have entered the stage of high hollowing. ② The traditional villages with hollowing index above 0.9 comprised 92%, and those between 0.8 and 0.9 made up 6%. Those with hollowing index at intervals 0.7-0.8, 0.6-0.7, and 0.5-0.6 accounted for 0.98%, 0.30%, and 0.11%, respectively. ③ Population hollowing is the fundamental cause of traditional village hollowing. In more than 99% of traditional villages, the population hollowing index was greater than 0.7. ④ More than 99% of traditional villages have a building hollowing index greater than 0.4, and more than 92% of the villages had a per capita number below 0.1. ⑤ The cultural hollowing rate for most traditional villages was very high. The cultural hollowing index for more than 99% of traditional villages was greater than 0.7. This study provides references for government administrators and scholars in rural revitalization and traditional village hollowing governance.

Maintaining Lumbar Spine Stability: A Study of the Specific and Combined Effects of Abdominal Activation and Lumbosacral Orthosis on Lumbar Intrinsic Stiffness

BACKGROUND

Two potential interventions for enhancing lumbar stability are to actively increase abdominal muscle activity, either through the abdominal drawing-in maneuver (ADIM) or bracing, and passively increase lumbar stiffness using a lumbosacral orthosis (LSO).

OBJECTIVE

To compare the increase in lumbar stiffness after 2 active interventions (ADIM versus bracing) and 1 passive intervention (LSO), and to evaluate the combined effect of active (abdominal bracing) and passive interventions.

METHODS

In this experimental and comparative study, lumbar stiffness, a surrogate measure of lumbar stability, was estimated in 25 healthy individuals during 7 trunk perturbation conditions: (1) control, (2) ADIM, (3) bracing at 5% of right external oblique maximal voluntary activation (5% bracing), (4) bracing at 10% of right external oblique maximal voluntary activation (10% bracing), (5) LSO, (6) LSO plus 5% bracing, and (7) LSO plus 10% bracing. Electromyographic biofeedback of the external oblique was provided on a monitor, while ultrasound was used for the ADIM to ensure a sustained contraction of the transversus abdominis.

RESULTS

The ADIM, 5% bracing, and 10% bracing active interventions generated comparable lumbar stiffness. However, considering that bracing can range from 10% to 20%, it may be superior to hollowing, as further estimated with a mixed-effect statistical model. Combining bracing and an LSO resulted in an additive effect on lumbar stiffness.

CONCLUSION

Bracing and ADIM produced comparable lumbar stiffness, as they were performed at the same overall abdominal activation levels (5% and 10% maximal voluntary activation). The independent effects of bracing and LSO raises the possibility of combining these interventions in some circumstances. J Orthop Sports Phys Ther 2019;49(4):262-271. Epub 18 Jan 2019. doi:10.2519/jospt.2019.8565.