جستجوی مقالات مرتبط با کلیدواژه « تغییرپذیری هماهنگی » در نشریات گروه « پزشکی »

Propose:

Patellofemoral Pain Syndrome (PFPS) is a common ailment among runners and those leading active lifestyles. This study aimed to explore the differences in the coordination variability and muscle functionality in the lower limbs of professional athletes afflicted with PFPS compared to their healthy counterparts during running.

Eighteen male athletes with Patellofemoral Pain Syndrome (PFPS) and 18 healthy male athletes participated in this study. Data recording was conducted using 6 Inertial Measurement Unit (IMU) sensors placed on both thighs, shins, and feet, along with surface electrodes on the vastus medialis, vastus lateralis, and gluteus medius muscles. The coordination variability and electrical activity of the lower limbs of each participant were examined while running at a self-selected speed on a treadmill for 21 minutes, during both the stance and swing phases at the test's beginning, and only during the stance phase at the test's end. An independent t-test was utilized for statistical analysis (p≥0.05).

Coordination variability between sagittal thigh-sagittal shin, sagittal thigh-transverse shin, transverse thigh-transverse shin, frontal thigh-transverse shin, sagittal shin-transverse foot, and transverse shin-sagittal foot was lower in the PFPS group compared to the healthy group during the stance phase (p≥0.05), and sagittal shin-transverse foot coordination variability was lower during the swing phase (p=0.001). The activation timing of the vastus medialis and gluteus medius muscles in the PFPS group was delayed compared to the healthy group (p=0.005 and p=0.002, respectively) and remained active for a longer duration (p=0.007 and p=0.001, respectively), with less overall activity (p=0.001).

The research indicates that the performance of the muscles studied may be a contributing factor to the reduced coordination variability observed in the lower limbs.

 Pyramid and reverse pyramid loading patterns are used to increase the training load in resistance training. Although physiological studies have attempted to compare the two patterns, the difference between the two loading patterns on the biomechanics of the spine and pelvis has not been determined. This study aimed to investigate the effect of pyramid and inverted pyramid loadings on spinal and pelvic coordination variability in squat movement.

 Twelve bodybuilding athletes in Tehran City, Iran, voluntarily participated in this study. The subjects performed squat movements as the pyramid and reverse pyramid at intensities of 50%, 70%, and 90% of ten maximum repetitions. Then, the kinematic information of the three segments of their spine and pelvis was recorded. Coordination and variability coordination were calculated using a modified vector coding method.

 The results of repeated measures analysis of variance showed a significant difference in the coordination pattern for pelvic-lower back coordination, lower-back to lower-trunk spine, and lower-trunk-to-upper-trunk spine in the intensity of 50%. A significant difference was observed in the coordination pattern, with an intensity of 70% for the lower back and lower trunk spine. Also, no statistical significance was observed between the pyramidal and inverted pyramidal loading types for spine and pelvis coordination.

 According to the results of increasing the load in pyramid loading and decreasing the load in reverse loading, the coordination of distal couplings affected the sagittal plane more than the proximal one. It is recommended to use the reverse pyramid method for exercises and be more careful when performing pyramid exercises.

Optimizing strategies to reduce the negative effects of lifts on low back pain (LBP) have attracted the attention of researchers. One of the practical strategies to deal with the effects of loads on the spine is lumbar belts. The aim of this study was to investigate the effect of lumbar belts on the coordination variability of spine and pelvis during repetitive lifts in male athletes with non-specific chronic LBP.

Twelve male athletes with chronic LBP participated in the study voluntarily. Participants with and without belts lifted the box for one minute at a frequency of 10 times per minute, and cinematic information based on the three-segment model of spine was recorded using a motion capture system equipped with 10 cameras. Coordination and coordination changes for these segments were calculated using a modified vector coding (VC) method. To compare the collected data, if normal, paired t-test was used in SPSS software and in variability data, statistical parametric mapping (SPM) method was used in MATLAB software with the significance level of P ≤ 0.05.

A significant difference was observed for the coordination of the pelvic segment to the lower back segment [concentric phase (P ≤ 0.035), eccentric phase (P ≤ 0.043)]. On the other hand, no significant difference was reported between using and not using belts for the coordination of the lumbar segment to the lower trunk segment (P = 0.545), lower trunk segment to the upper trunk segment (P = 0.440), and the variability of all calculated couples

According to the findings, using the belt may optimize the transfer of motion from the distal segment to the proximal segment, which can reduce the pressure on the waist and prevent injury and pain in the lumbar region. Therefore, it is recommended that athletes with LBP use a belt when lifting heavy loads in order to transfer movement from the distal to the proximal segment correctly.

 The purpose of this research was to compare the coordination variability of lower extremity segments in men with genu varum and healthy men during treadmill running at different speeds.

 Among sports and physical education students, 15 healthy men and 15 men with genu varum voluntarily participated in this research. Each participant ran on treadmill for 60 seconds at preferred speed and 25% faster and 25% slower than preferred speed. The kinematics data of lower extremities were collected by MyoMotion motion analysis system at 200 Hz sampling frequency. Coordination calculations were done by continuous relative phase (CRP) method for three segments coupling and compared between two groups.

 The results of repeated measures analysis of variance (ANOVA) between groups showed that coordination patterns of segments did not differ significantly between the groups during running at different speeds (P ˃ 0.05). However, the change in running speed caused significant differences in coordination and coordination variability of segments in some phases of running in two groups (P ≤ 0.05).

 Coordination pattern of segments during running seems the same between genu varum and healthy groups; however, significant differences in these patterns and different running speeds were evident in both groups. On the other hand, coordination variability of segments was not different between groups, but the increase in running speed reduced the coordination variability during early and late swing and mid-stance phase of running in both groups. This finding may imply higher risk of overuse injuries at these phases.