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The Effect of Non-Slippery Flooring on Postural Stability and Gait Parameters in Severe Osteoporosis Elderly
Ramin Rafeie, Mohammad Eftekhari Yazdi, Koorosh Nakhaee, Siamak Khorramymehr,
Volume 10, Issue 3 (12-2022)
Abstract
Objectives: Investigating the effective factors in controlling and increasing stability due to weakening of the balance parts of the body in the elderly with osteoporosis, in order to prevent falling is of particular importance, so in this study, the effect of anti-slip flooring in the stimulation of the somatosensory part of the sole of the foot to improve postural stability and gait balance has been evaluated in the elderly with osteoporosis.
Methods: 22 elderlies participated (11 elderly women with severe osteoporosis,11 healthy elderly women) in this study in two static and dynamic condition on three different surfaces including sponge non-slippery flooring (FL), PVC patterned non-slippery flooring (SF) and control surface (CO). In the static part, each participant was standing on the force plate for 30 seconds with eyes open and eyes closed. The values of the length, sway and average velocity of the anterior-posterior and internal-external center of pressure of the foot were measured. In the dynamic part, each participant walked at a selected speed on different surfaces and the values of the normalized step and stride length, step width, step and stride time, and average step and stride velocity were measured.
Results: PVC non-slippery flooring (SF) and control surface (CO) reduced all postural stability and gait variables (P < 0.05) in osteoporosis and healthy elderly than soft Sponge Surface (SF). Moreover, all postural stability variable and spatial and temporal gait parameters were significantly more in the osteoporosis elderly than in healthy elderlies (P < 0.05). Moreover, anterior-posterior mean velocity in open-eyed state significantly reduced in both elderly groups than close-eyed state (P < 0.05).
Conclusion: Stiff and patterned surfaces are more effective than soft spongy surfaces in stimulating the somatosensory part of the foot sole to improve stability in both osteoporotic and healthy elderly groups. The results of this study may be helpful to understand the characteristics of the elderly while walking and standing on non-slippery flooring in different environments and the ergonomic design of the environment in order to reduce slips and falls and as a result possible fracture in the elderly with severe osteoporosis. In addition, observation of instability between the elderly with osteoporosis and healthy suggests the need for further investigation and the use of auxiliary exercises to correct and improve stability.

Muscular Synergy of Trunk and Hip Segments in Carrying Hand Loads with Different Weights in Healthy Young People
Saeed Ilbeigi, Masoumeh Al-Eghabi, Mohammad Yousefi, Mohammad Hamed Hosseini,
Volume 12, Issue 3 (12-2024)
Abstract
Objectives: Designing one-handed carrying tasks based on biomechanical findings has a significant impact on preventing musculoskeletal injuries. The present study was conducted to investigate the muscle synergy of the trunk and pelvis in the manual carrying of loads with different weights in healthy young people.
Methods: In this experimental study, 20 male volunteers performed the walking protocol without load, carrying different weights of 5%, 10%, and 15% of their own weight during unilateral manual load carrying. The electrical activity of the trunk and pelvis muscles while carrying loads of different weights was recorded using an electromyography device (Biovision). To evaluate the differences between different load-carrying conditions, a repeated measures test was used at a significance level of P≤0.05.
Results: The results showed that in the performance of manual load carrying, there was a significant difference between muscle synergy (synergy size) in all walking protocols, including 5% and 10% of body weight and 5% and 15% of body weight and between 15% and 10% (P≤05). While in the performance of manual load carrying, a significant difference was found between muscle synergy (synergy direction) in 5% of body weight and 10% of body weight, this difference was not seen in manual load carrying with 5% of body weight and 15% of body weight and also between synergy of 15% and 10% (P≥0.05).
Conclusion: It seems that the difference in muscle synergy in terms of size in unilateral manual load carrying can, with increasing load, create more tension in the back and pelvic muscles; however, the direction or angle does not change compared to the no-load state.

Comparison of the Pattern of Muscle Synergy during Load Lifting with Two Techniques among Women with Non-specific Back Pain in the Healthy Group
Fateme Rezaie Pourmashizi, Behrouz Hajilou, Rashid Heidarimoghadam, Sara Anbarian, Mehrdad Anbarian,
Volume 13, Issue 1 (5-2025)
Abstract
Objectives: The core muscles of individuals with low back pain show a different activity pattern than the healthy group during load lifting. This issue may be due to changes in spinal control mechanisms, such as muscle synergies. The present study aimed to compare the synergy pattern of selected core muscles and lower limb muscles during load lifting and lowering with two different techniques among females with non-specific back pain in comparison with the healthy group.
Methods: A total of 18 healthy females with non-specific back pain and 18 match controls participated in this study. The activity of 8 muscles of the core and lower limbs was recorded while lifting a load of 10% of the subject's mass with stoop and squat techniques. Then, the pattern of muscle synergies was extracted using the non-negative matrix factorization algorithm. Pearson's correlation method and independent t-test were used to compare synergy patterns (P<0.05).
Results: Patients with back pain had a different muscle synergy pattern than those in the healthy group in stoop and squat techniques. The peak muscle synergy patterns of patients in both techniques were different from those of healthy subjects and were created in a different time cycle of lifting the load.
Conclusion: This study indicated that individuals with non-specific back pain use different synergy patterns during load lifting, and the body's control system may respond differently in patients with non-specific low back pain compared to healthy individuals. The changes observed in the relative weight of muscles in patients and healthy people may be caused by the changes in muscle synergy patterns, which require further studies.

The effect of upper material in military boots on lower limb loading during walking
Abbas Farjad Pezeshk, Saeed Ilbeigi, Mohammad Reza Vafaiee,
Volume 13, Issue 2 (9-2025)
Abstract
Background and Objectives: The role of shaft stiffness in military boots is widely recognized, yet most research focuses on quantifying stiffness rather than examining how material composition of boot shaft influences performance. This study explores how different boot materials affect kinetic parameters, comparing conventional leather boots to a hybrid leather-synthetic design to assess their impact on mobility and biomechanical efficiency.
Methods: A repeated-measures experimental design was employed, assessing twenty healthy male participants under four conditions: walking with a formal shoe and three military boot types, each featuring distinct shaft materials (two leather and one a hybrid leather-synthetic design). Ground reaction forces (GRF), rate of force development (RFD), impulse was recorded using a force plate. Statistical analysis involved repeated-measures ANOVA with Bonferroni correction.
Results: Featuring synthetic materials in the shaft, boot 3 showed reduced negative impulse, and elevated positive impulse relative to traditional leather boots during gait.
Conclusions: These findings highlight the biomechanical advantages of hybrid boot designs, suggesting that reduced shaft stiffness improves mobility and motion efficiency. The study underscores the need for optimized traditional boot materials to enhance gait performance while minimizing injury risks, particularly for military personnel.

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