جستجوی مقالات مرتبط با کلیدواژه "نیروی عکس العمل" در نشریات گروه "پزشکی"

Knee genu varum is one of the lower limb abnormalities associated with biomechanical changes in lower limbs. The present study aims to compare the effects of shoe lifespan on ground reaction force (GRF) components in women with knee genu varum and healthy peers during running.

The is randomized clinical trial. Participants were 15 female college students with knee genu varum and 15 healthy peers. A new pair of sport shoes was given to each participant during to wear them for six months. Then, they were asked to run at a preferred speed in three trials with the new shoes (pre-test phase) and three trials with the used shoes (post-test phase) in a path where a force plate was installed. Statistical analysis was conducted by using repeated measures ANOVA. All analyses were done in SPSS v. 23 software. The significance level was set at 0.05.

 The results indicated the significant main (group) effect of shoes on peak anterior-posterior GRF during heel contact and on the anterior-posterior impulse (P<0.018, d>0.8). The values of these variables in the genu varum group were significantly higher than in the healthy group. Moreover, findings showed the significant main effects of shoes on the time to reach the peak GRF during heel strike and on the loading rate (P< 0.02, d > 0.9). The time to reach the peak GRF during heel strike with the used shoes was shorter than with the new shoes (P= 0.015, d=0.9), while the vertical loading rate during running with the worn shoes was greater than with the new shoes (P=0.019, d=0.9).

 Running with shoes having a lifespan >6 months is a risk factor for women with knee genu varum.

Running poses an essential role in maintaining cardiovascular health. However, it has been demonstrated that 2.5 to 38 injuries per 1,000 hours of running can occur. The purpose of this study was to investigate ground reaction forces components during running with running shoes compared to control shoes in individuals with genu varum.

This study was laboratory and semi-experimental. The statistical society includes all male students at the University of Mohaghegh Ardabili. The subjects of the study consist of 15 healthy males and 14 males with genu varum. Ground reaction force components were recorded using Bertec force plate during running in four conditions: barefoot, running shoes (Alborz shoes and agility shoes), and control shoes. Two ways ANOVA with repeated measure was used for statistical analyses.

Peak lateral ground reaction force at heel contact with Alborz shoes were higher than that of control shoes (P = 0.001). Peak anterior ground reaction force component at the push-off phase with agility shoes were lower than those in control shoes (P < 0.003) and barefoot (P < 0.019) condition.

Since Alborz shoes were able to reduce the peak lateral ground reaction force, using these shoes was recommended to reduce injuries. However, further study in this field is warranted.

Investigating the risk factors during single crossover landing in people with flat foot complication is unknown. Therefore, the aim of the present study is to compare the ground reaction forces and the amount of load introduced during crossover landing in people with flat foot and healthy individuals.
  

The study method is descriptive-comparative. Twelve male subjects with low longitudinal arch (age = 24.67 ± 4.45; height= 176.12 ± 5.64; Weight= 765.62 ±11.2) and twenty-two matched healthy control subjects (age=23.47 ±5.63; height= 178.66 ± 3.87; Weight= 714.31 ±13.61) participated in this study. Based on the Arch Height Index (AHI), was divided into two healthy and healthy groups with flat feet. The ground reaction force was measured using a force plate (1000 Hz) during crossover-landing. Then, the kinetic indicators, including the peak of the ground reaction force and the time to reach them and the loading rate, were extracted by Vicon Nexus 1.8.5, Polygon 4.1.2 software. Data were analyzed with SPSS. 23.

People with flat feet have fewer vertical ground reaction force (FZ1,2,3) when crossover landing compared to healthy individuals (P <0.05). The time to reach the minimum vertical force of the action photo (valley) at the moment of contact of the toe with the ground (TFZ2) is faster in people with flat foot complication (P = 0.022).

People with flat feet had less vertical force, less vertical reaction time, and faster reaction time than healthy people, and these factors were considered as a risk factor for increasing fracture of 1-3 metatarsal and ankle sprain. Therefore, it is recommended to teach strategies to prevent these risk factors in activity and rehabilitation.

Aims and The purpose of this study was to compare the parameters of ground reaction force during landing in patients with chronic low back pain. Material and 21 healthy men and 21 men with chronic low back pain participated in this study. Using a Kistler force plate )1000Hz) GRF during landing was measured. Then, maximum GRF and their related time-to-peak, impulse and loading rate were obtained. Independent t student was used to analyze the data (α=0.05). Findings: People with chronic low back pain have lower internal-external GRF and have a lower vertical GRF to touching the ground )FZ2) when landing compared to healthy people. Patients with chronic low back pain have a lower loading rate(Y)(P=.049). People with low back pain have a higher vertical ground reaction force than healthy people, and these factors are considered as a risk factor for increasing compressive forces to the spine.

Although the main goal in Perthes disease treatment is to increase the contact area between the femoral head and acetabulum and also to reduce the pressure applied on the hip joint, but no treatment was successful in this field. It seems that not any study has yet investigated the effect of orthoses on joint reaction force in Perthes disease. The purpose of this study was to assess the hip joint reaction force in Perthes disease with and without the use of Scottish rite orthosis. The research is a case series study. In this study, among 10 patients suffering from perthes two seven-years-old boys with Perthes disease in the right hip joint were selected. These boys had no history of orthopedic and other structural problems. They were asked to walk in the lab space with and without Scottish rite orthosis. Open SIMM software for evaluation of joint reaction force was used in both situations. Using paired t-test, the difference between kinetic and kinematic parameters for each individual was analyzed. The findings of this study indicated that ground reaction force was increased during the use of orthotics, although it seems that joint reaction force is reduced with the use of orthotics (P= 0.05). Use of orthoses can affect the kinematic of hip joint and pelvic. Since the joint reaction force is one of the most important parameters that affected the joint destruction and deformity, it can be said that the use of orthosis can affect the final joint deformity. Thus, it is recommended that further research be carried out on more cases.