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Zahra Ghahremani, Hassan Daneshmandi, Mehrdad Anbarian,
Volume 21, Issue 26 (12-2023)
Abstract
The purpose of this study was to assess the acute effect of warm-up protocols (general and post-activation potentiation) on vertical jump performance and jump-landing technique in female handball players with trunk dysfunction. Twelve trained female handball players with trunk dysfunction participated voluntarily in this study. Subjects randomly performed three different warm-up protocols on separate days: 1- general warm-up protocol, 2- general warm-up with 2 repetitions of dynamic half-squat at %90 of one repetition maximum, 3- general warm-up with 2 repetitions of static half-squat at %90 of one repetition maximum. In the fifth minutes of recovery period after 3 protocols, subjects performed vertical jump and the Landing Error Scoring System tests, and Landing Error Scoring System scores, valgus and flexion angles, and vertical jump height was assessed. ANOVA with repeated measures was used for statistical data analysis. The jump height increased significantly after performing the second and third protocols related to general warm-up (p=0.039, p=0.047 respectively), but there weren’t a significant difference in Landing Error Scoring System score, valgus and flexion angles for three protocols. It seems that the special warm-up method by post-activation potentiation can improve vertical jump performance without influencing Anterior cruciate ligament injury risk.
Seyed Mohammad Hosseini, Seyed Vahid Seyedazizi, Sahar Bala Khiyavi, Ali Keshtiaray,
Volume 21, Issue 26 (12-2023)
Abstract
The researchers conducted the present study with the aim of investigating the pain and muscle disorders of patients with covid-19 with people who have experienced it. The research was applied and comparative. Samples were calculated using G-power of 303 people, and sports teachers were excluded from the research. The Nordic questionnaire was provided to Ardabil education and training employees after the investigation, the number of people with one year of identification and the number of 113 people with the age range of 30 to 45 years reported no reduction. Then, musculoskeletal disorders of 9 body areas in both groups were evaluated using descriptive statistics and chi-square test at a significance level of 0.01. The muscle pain of the affected group was significantly (P<0.01) higher than that of the healthy group, and also based on the chi-square test, the amount of back and neck pain was 52% and 45%, respectively, in affected people compared to other organs. It was more meaningful. (P<0.01) noticed that there was no significant difference between the pain and discomfort of different organs in the non-observed group. Corona patients may experience pain, and the cause of it in the Nordic questionnaire, in addition to physical abnormalities and excessive muscle disease, can be from Corona disease; Therefore, the Nordic questionnaire should be used.
Mohadeseh Ashrafizadeh, Ali Asghar Norasteh,
Volume 22, Issue 28 (12-2024)
Abstract
Jumping motor tasks in people with motor control defects are probably associated with incomplete movement patterns, which can be related to non-collision injuries of the lower limbs. Therefore, the aim of the present study is to investigate the eight-week training program of feedback on the biomechanical variables of athletes with selected motor control defects in landing jump tasks.
The present study is a randomized clinical trial study before and after the intervention. 34 male recreational athletes with movement control defects were selected based on the study criteria and then randomly assigned to control and feedback groups. To analyze the data, two-way analysis of variance and Bonferroni statistical tests were used for each movement task at a significance level of P < 0.05.
The results of the study indicated an increase in the electrical activity of the VM and GM muscles in different phases of jumping in the feedback group. Also, the feedback group showed a decrease in knee valgus angle in the frontal plane (P < 0.05).
The results of the present study showed that feedback can be used to correct incomplete movement patterns in jump-landing tasks.
Mohadeseh Ashrafizadeh, Ali Asghar Norasteh,
Volume 23, Issue 30 (1-2026)
Abstract
Introduction & Aim: Motor control deficits such as dynamic knee valgus and quadriceps dominance are recognized as key modifiable risk factors for lower-limb injuries. Feedback-based training has been proposed as an effective strategy to correct high-risk biomechanics. This systematic review aimed to investigate the effects of feedback interventions on lower-limb mechanics and performance during jump-landing movements
Methods: A comprehensive search was conducted in international databases (PubMed, Scopus, Science Direct, Google Scholar) and national databases (Magiran, Irandoc) from 2000 to 2023. Studies were included if they examined the effects of any form of feedback on healthy individuals with lower-limb motor control deficits. From an initial 540 retrieved articles, 20 studies met the inclusion criteria after screening and full-text review.
Results: Most studies reported that feedback, particularly external or real-time feedback, led to increased flexion angles of the hip and knee in the sagittal plane during jump-landing. The findings regarding frontal plane mechanics were inconsistent: some studies showed a reduction in knee valgus angle, while others reported no significant change. A majority confirmed a reduction in peak vertical ground reaction force following feedback. However, limited studies assessed performance outcomes such as jump height or reactive strength index, and their findings were contradictory.
Conclusion: Feedback interventions appear effective in improving biomechanical risk factors related to lower-limb injury during jump-landing tasks; however, their impact on functional performance remains unclear. Further research is required to determine long-term retention and performance outcomes.
