The maintenance of stability is intricately tied to the precise adjustment of the body’s center of gravity within the base of support . This process involves continuous and fine-tuned coordination of motor commands, sensory feedback, and postural adjustments. While the human body effortlessly accomplishes this task, various factors can disrupt this delicate balance, leading to a loss of stability.
One critical factor influencing stability is the distribution of body weight, which, if asymmetrical, can jeopardize equilibrium. Postural stability is a multi-faceted process that integrates sensory information from visual, proprioceptive, and vestibular systems [2,3,4,5].
The central nervous system processes these inputs to orchestrate the necessary muscular responses for maintaining balance . However, when this sensory processing is compromised, it can result in impaired postural stability control .
Sensorimotor Integration and Postural Control
Central to postural stability is the integration of sensory information from visual, proprioceptive, and vestibular systems. These systems work harmoniously to provide a comprehensive picture of the body’s position in space. Visual cues allow for spatial orientation, while proprioceptive input informs the brain about limb and body position. The vestibular system contributes information about head movement and spatial orientation.
This integration is crucial for stability, as evidenced by studies where postural sway during standing was increased due to targeted manipulations of peripheral sensory inputs [3,4,13,14]. These findings emphasize the significance of peripheral signals in detecting positional changes and the central processing of these signals in maintaining stability.
Posture’s Role in Stability
The influence of posture on stability cannot be understated. Variations in spinal alignment and body part positioning can significantly impact stability [15,16,17,18]. Postural deviations such as sway back, rounded shoulders, hyperkyphosis, hyperlordosis, and forward head posture alter the activation of muscles responsible for maintaining balance . The forward head posture and hyperkyphosis have been linked to increased postural sway [18,20,21], suggesting that posture directly influences neuromuscular control and the body’s center of gravity.
Self-Mobilization Exercise for Postural Correction
Recognizing the importance of posture, a novel self-mobilization exercise program was developed to address spinal curvature deviations like hyperkyphosis, hyperlordosis, and forward head posture [22,23]. This exercise program aims to induce joint mobilization-like effects through self-initiated movements while lying supine.
Previous studies have shown that this self-mobilization exercise program can lead to a decrease in anterior-posterior (AP) postural sway when standing on an unstable platform . However, these findings lacked detailed analysis of the plantar center of pressure (CoP) movements, a critical element in postural stability assessment.
This study seeks to elucidate the influence of the self-mobilization exercise program on postural stability. The primary objective is to examine the impact of the exercise program on various sway parameters while standing on a stable surface. Specifically, the study aims to investigate changes in plantar CoP relative to the base of support during static standing.
Based on prior research, it is hypothesized that the self-mobilization exercise program will lead to a decrease in postural sway parameters, particularly in the AP direction [16,22,23]. This is grounded in the understanding that the exercise program addresses spinal curvature deviations associated with increased postural sway.
Furthermore, the secondary hypothesis is that changes in sway parameters will be consistent regardless of whether participants stand with eyes open or closed, based on previous findings .
This study investigated the impact of a self-mobilization exercise program designed to realign spinal curvature on postural stability as measured by center of pressure (CoP) sway parameters during static standing on a stable surface.
The findings shed light on the effects of the exercise program on postural control and provide insights into the underlying mechanisms contributing to improved stability.
The main outcomes of the study revealed that there was no significant difference in CoP sway parameters between the pre- and post-test measures for both groups with eyes open. However, a notable outcome was observed in the Exercise group with eyes closed. In this group, there was a significant decrease in the area, distance, excursion, and root mean square (RMS) displacement of the CoP sway in the anterior-posterior (AP) direction.
The root mean square (RMS) displacement of the CoP sway in the anterior-posterior (AP) direction is a measure of the variability of the center of pressure (CoP) in the AP direction. The CoP is the point of application of the ground reaction force, and it is constantly moving as we stand or walk. The RMS displacement of the CoP sway is a measure of how much the CoP moves from its average position.
A high RMS displacement of the CoP sway in the AP direction indicates that the CoP is moving a lot, which can be a sign of instability. This can be caused by a number of factors, such as fatigue, decreased muscle strength, or neurological disorders. A low RMS displacement of the CoP sway in the AP direction indicates that the CoP is moving less, which is a sign of stability.
The RMS displacement of the CoP sway in the AP direction can be measured using a force platform. A force platform is a device that measures the ground reaction force. The RMS displacement of the CoP sway can be calculated from the data collected by the force platform.
The RMS displacement of the CoP sway in the AP direction is a useful measure of postural stability. It can be used to assess the risk of falls in people who are at risk of falling, such as older adults or people with neurological disorders. It can also be used to monitor the effectiveness of interventions that are designed to improve postural stability.
Here are some of the factors that can affect the RMS displacement of the CoP sway in the AP direction:
- Fatigue: As we become fatigued, our muscles become weaker and our ability to maintain balance decreases. This can lead to an increase in the RMS displacement of the CoP sway in the AP direction.
- Decreased muscle strength: If we have decreased muscle strength in our legs, we will have less control over our balance. This can also lead to an increase in the RMS displacement of the CoP sway in the AP direction.
- Neurological disorders: People with neurological disorders, such as Parkinson’s disease or multiple sclerosis, often have difficulty controlling their balance. This can lead to an increase in the RMS displacement of the CoP sway in the AP direction.
- Age: Older adults tend to have less muscle strength and flexibility than younger adults. This can make them more susceptible to falls, and can lead to an increase in the RMS displacement of the CoP sway in the AP direction.
If you are concerned about your postural stability, you should talk to your doctor. They can assess your risk of falls and recommend interventions that can help to improve your balance.
Importantly, these changes indicate not only reduced overall CoP movement but also diminished CoP fluctuation. These results underscore the effectiveness of the self-mobilization exercise program in enhancing postural stability.
The study’s findings align with prior research, which also demonstrated a reduction in AP postural sway after the self-mobilization exercise program, consistent across various CoP sway parameters . The mechanism behind this reduction can be attributed to the positioning participants adopt during the exercise program.
The supine lying position on a pole, where only select body areas are supported, induces a gravitational pull on unsupportive body parts. This gravitational force promotes posterior movement, resulting in changes in spinal alignment and improved postural stability in the AP direction. The exercise program appears to influence postural stability selectively in the AP direction, which is governed by ankle muscle activation and control [28,29].
Interestingly, the study highlighted that changes in postural stability were observed only in the eyes-closed condition. This suggests that the exercise program’s impact on stability was more pronounced when visual feedback was eliminated as a contributing factor.
In challenging conditions where visual cues are absent, the body relies more on the vestibular and proprioceptive systems for stability control. The exercise program seems to facilitate the shift in sensory integration towards these more reliable systems during the eyes-closed condition.
Nevertheless, certain aspects remain unclear and warrant further investigation. The exact mechanisms underlying the sensory shift that leads to reduced postural sway need deeper exploration. Moreover, the study’s scope was limited to static standing, so future research should explore the exercise program’s effects in dynamic tasks such as gait.
Additionally, considering the study’s inclusion of healthy young adults, extending the findings to patient and elderly populations is essential to ascertain the program’s broader applicability.
In conclusion, the self-mobilization exercise program demonstrates its potential to enhance postural stability in the AP direction. The posterior gravitational pull during exercises contributes to improved spinal alignment and subsequently, reduced postural sway. The exercise program’s effects on stability are direction-dependent and emphasize the importance of proper sensory integration.
These findings have valuable implications for healthcare professionals, including physical therapists, athletic trainers, and conditioning coaches. The exercise program’s successful distribution of the center of mass and improved postural symmetry can be extrapolated to various contexts and directions, further enriching therapeutic interventions and enhancing overall postural control.
As a result, the study not only contributes to the understanding of postural stability mechanisms but also presents a practical application for clinical settings.
reference link : https://www.mdpi.com/2073-8994/15/7/1321