anterior cruciate ligament

Considering the high prevalence of anterior cruciate ligament (ACL) injuries, several attempts have been made to repair the ligament to bring it closer to the natural anatomy. Using autografts such as the semi tandinousus and gracilis tendons (double-strand method) is the common surgical method to reconstruct ACL. However, to reconstruct ACL, using an autograft of quadrupled semitendinosus grafts (single-strand method) may have the same results and fewer complications than the first technique. Yet, there is not enough evidence in this regard. In this study, the results of using the two autografts to reconstruct ACL were compared.

Patients with ACL tear were enrolled in the study and divided into two groups (undergoing double-strand or single-strand graft surgery). After operation, all patients were assessed by using clinical examinations and Iysholm questionnaire. The results were compared between two groups.

Twenty nine patients under 30 years were enrolled in the study; 19 patients in the single- strand (n = 19) and 20 patients in the double strand groups (n = 20). There was no significant difference between two groups in terms of height, weight, body mass index (BMI), complications, and scores of Iysholm and pivot shift tests.

There were not significant difference between the two groups in terms of height, weight, BMI, complications and activity. Therefore, depending on the patient's condition and the length and diameter of the graft, one or both of the methods can be selected to reconstruct ACL.

Diagnosing an anterior cruciate ligament (ACL) rupture based on a physical examination is a challenge for both surgeons and surgeon’s assistant. The Lever sign test has been developed as a new physical examination to overcome the practical limitations of routine clinical trials and optimize diagnosis. The aim of the present study was to evaluate the reliability and diagnostic value and outcome of the Lever test.

In this prospective diagnostic study, 154 patients who were candidates for arthroscopic surgery were evaluated. Prior to the tests, patients' clinical manifestations were recorded. Lever, Drawer, Lachman and pivot diagnostic tests were performed by an orthopedic surgeon and an experienced surgeon assistant before and after anesthesia. The accuracy, sensitivity and specificity of these tests compared to arthroscopy findings were calculated as a gold standard. The ease of performing the tests was assessed from the point of view of the performers as well as the patients' pain during the test with the standard pain score (Visual Analog Scale, VAS).

The accuracy, sensitivity and specificity of Lever test before anesthesia were calculated as 70.5, 63, and 91.3 and after anesthesia 74.5, 66.51, 90.23 respectively. Among the tests, Lever was the easiest before anesthesia with 68%, and after anesthesia with 74.5% it was the easiest after drawer test from the point of view of the operators. Lever test with a vas score of 4.01 had the least pain during the test.

The lever test can be performed clinically easily and has little pain for the patient and is comparable to other orthopedic tests in terms of accuracy, sensitivity and specificity. This test is recommended as an effective orthopedic maneuver, along with other ACL tear diagnostic tools, especially when other tests are associated with severe pain.

Gait is a fundamental movement pattern influenced by various structures. This study aimed to determine the effect of sand-based training on ground reaction force frequency spectrum in individuals with anterior cruciate ligament (ACL) reconstruction and pronated feet during gait.

This clinical trial was conducted on 28 male students with pronated feet and ACL injuries aged 22-25 years at Mohaghegh Ardabili University. Participants were randomly assigned to two groups of 14: A control group and a sand-based training group. The ground reaction force variables were measured using a force plate in the pre-test and post-test.

The number of necessary harmonics in the free moment component decreased by 15.95% in the post-test (16.48±4.14) compared to the pre-test (19.11±2.15) of the control group (P<0.05). The number of necessary harmonics in the mediolateral direction of the ground reaction force decreased by 23.34% in the post-test (15.59±3.92) compared to the pre-test (19.23±2.66) of the training group (P<0.05). Additionally, the number of necessary harmonics in the anteroposterior direction of the ground reaction force increased by 33.04% in the post-test (21.61±2.55) compared to the pre-test (14.47±4.11) of the training group (P<0.05).

Sand-based training was able to improve the gait mechanics of individuals with ACL reconstruction and pronated feet.

Identifying neuromuscular adaptations in knee muscle activity after anterior cruciate ligament reconstruction in daily tasks has clinical value. This study aimed to investigate the electromyographic activity of selected lower limb muscles in people with anterior cruciate ligament reconstruction and healthy people descending from two heights of 25 and 40 cm.

Ten males who had undergone Anterior Cruciate Ligament Reconstruction (experimental group) and ten healthy males (control group), all aged between 20 and 30, were included in the study. The electromyographic activity of the Vastus Medialis Oblique, Vastus Lateralis, Rectus Femoris, Biceps Femoris, and Gastrocnemius muscles in landing from heights of 25 cm and 40 cm was measured using a surface BTS-EMG system (2000 Hz). The signals' maximum Root Mean Square values were normalized based on Maximum Voluntary Isometric Contraction and then compared between the two groups.

At a height of 25 cm, the muscles' EMG activity, except for the RF muscle, was lower in the Anterior Cruciate Ligament Reconstruction group than in the control group. The root mean square of Vastus Medialis Oblique in the anterior cruciate ligament reconstruction and control groups were significantly different (P=0.026). The results showed that at the height of 40 cm, the Root Mean Square in the Anterior Cruciate Ligament Reconstruction group was lower than that in the control group. Also, the level of Biceps Femoris activity in the Anterior Cruciate Ligament reconstruction group and the control group was statistically significant (P=0.013).

Two years after anterior cruciate ligament surgery, there were no differences in knee muscle activity during landing from different heights. More research is needed on gender differences, graft types, functional status, and the association between muscle activity patterns and re-injury risk.

 One of the most common sports injuries is the anterior cruciate ligament (ACL) injury. So far, research has supported the positive effect of training instructions based on an external focus of attention, but no study has been conducted on the effect of a holistic focus of attention in ACL injury prevention. This study aims to compare the effects of holistic and external focus of attention on single-leg jump length and knee flexion range of motion (ROM) of female athletes at risk of ACL injury.

This is a quasi-experimental study. Thirteen female athletes prone to ACL injury (diagnosed the by Tuck jump test) with a mean age of 23.77±4.42 years were selected purposefully. They performed three jumps under each instruction condition (control, external focus, and holistic focus) and nine jumps in total. The single-leg hop test was used to assess the jumping performance of the participants. The effect of the order of conditions was controlled by counterbalancing. Thus, after three jumps in the control condition, group 1 first performed three jumps under the holistic-focus condition and then three jumps under the external-focus condition, while group 2 performed the jumps in the reversed order. Data analysis was performed using repeated measures ANOVA, followed by pairwise comparisons using the Bonferroni test. P<0.05 was considered statistically significant.

 According to the results of ANOVA, the effect of the focus of attention on the jump distance and knee flexion ROM was significant (P=0.001, P<0.0001, respectively). The pairwise comparisons showed that the jump distance and knee flexion ROM under the external-focus condition were significantly higher than under the control condition (P=0.002), but there was no significant difference between the external- and holistic-focus conditions in the jump distance (P=0.622) and knee flexion ROM (P=0.965). The difference in the jump distance between holistic-focus and control conditions was not significant (P=0.078), but the knee flexion ROM was significantly higher under the holistic-focus condition than under the control attention (P=0.001).

 It seems that the instructions using the external or holistic focus of attention can increase knee flexion ROM, and the external-focus instructions can increase the single-leg jump performance in female athletes prone to ACL injuries.

Posterior tibial slope (PTS) is a crucial radiographic measurement to determine the tibial plateau angle relative to its shaft.

In this study, PACS images related to 612 patients who had visited the hospital for reasons such as knee injury or pain, physical examination, or knee reevaluation and had undergone X-ray examination were examined. PTS measurements were obtained using the GE CENTRICITY PACS software and subjected to analysis.

The distribution of mean PTS in right and left angles revealed no significant difference between the two groups (P = 0.830). Comparing the mean PTS distribution between men and women, there was no significant difference in left and right PTS (P > 0.05). Additionally, comparing mean PTS between the right and left sides across different age groups showed statistically significant differences (P < 0.001).

This study identified the normal range of PTS values in knee joints of healthy Iranian adults, which can serve as a guide for personalized treatments. We hope that the results of this study will encourage knee prosthesis manufacturers to consider the obtained PTS measurements, as well as gender and age differences, in their product development for the Iranian population.

 Asymmetrical gait mechanics after anterior cruciate ligament reconstruction (ACLR) are associated with the development of post-traumatic knee osteoarthritis. Current measures of gait mechanics have focused on peak magnitudes of knee kinematics, kinetics, and joint contact forces; nonetheless, they have seldom considered the plantar pressure and muscular frequency content in individuals with ACLR and pronate feet (PF). The present study aimed to compare ACLR and PF with healthy controls during walking.

The present study was conducted based on a quasi-experimental and laboratory design. The sample of this study comprised 13 people with ACLR and PF and 13 subjects from the healthy group. The mean age scores of patients in the two groups of healthy and sick participants were 22.9±4.1 and 23.2±4.5 years, respectively. During the test, subjects walked barefoot on an 18-m runway. Peak plantar pressure variables in both groups were recorded by a foot scan system (sampling rate: 300 Hz). The electromyography activity of the tibialis anterior, gastrocnemius medialis, vastus lateralis, vastus medialis, rectus femoris, biceps femoris, semitendinosus, and gluteus medius were recorded during walking.

The results demonstrated that the peak midfoot region plantar pressure values (P=0.018) were higher in the ACLR/PF group than in the healthy group during walking. In addition, the results highlighted a significant difference in the muscle frequency content of the rectus femoris (P=0.012, d=0.68) and vastus latelarlis (P=0.042) during the loading response and push-off phase in the ACLR/PF group compared to the healthy group during walking.

Peak plantar pressure values at the midfoot region and rectus femoris and vastus lateralis muscular frequency content in the ACLR/PF group differed from that of the healthy group during walking.

The risk of anterior cruciate ligament (ACL) injuries in childhood has increased in recent decades and could be a major threat to a child's sports career. An increased risk of ACL injury is associated with dynamic knee valgus (DKV). Therefore, this study aimed to analyze the effect of an ACL injury protocol on the LESS, proprioception, and DKV of child soccer players.

In this study, thirty male football players with DKV (mean ± SD: age 11.40 ± .72 years, weight 36.62 ± 4.68 kg, height 141.10 ± 3.98 m) were randomly assigned into two groups: control (n=15) and training (n=15). Single-leg landing, LESS, and knee joint proprioception tests were administered before and after the implementation of the training protocol. After identifying the variables, the training group performed the injury proprioception program for eight weeks, with three training sessions each lasting 20–25 minutes per week. The control group continued their normal warm-up routine. To examine the difference between the pre-test and post-test, repeated measures ANOVA was conducted using SPSS 26 software with a significance level of 0.05.

The results of the research showed that after eight weeks of the injury prevention program, there was a significant improvement in reducing the valgus angle of the knee (p=0.005, F=9.369, η²=0.251), reducing the LESS scores (p=0.002, F=12.374, η²=0.306) and improving proprioception (p=0.003, F=10.251, η²=0.268).

According to the results of the research, it can be concluded that Stop-X injury prevention program can lead to improvements in knee valgus pattern, LESS and proprioception in child soccer players. Using the results of this research is recommended to soccer coaches and training experts.

Strengthening and improving neuromuscular control in various ways, including technique modification, in order to prevent sports injuries, as a principle, is always of interest to researchers and athletes. Landing technique after jumping during sports such as volleyball is known as one of the most important non-contact mechanisms of knee joint ligament injury. The purpose of this study was to investigate the effect of dynamic neuromuscular stability (DNS) exercises on knee functional tests in female athletes.

30 female volleyball players (age 22.06±3.39 years, height 1.67±0.04 m, weight 63.70±8.86 kg and body mass index 22.81±3.38 kg/m2) with at least three years of experience in volleyball training, they participated in this research and were randomly divided into two control groups (15 people) and an experimental group (15 people). Tuck Jump and Landing Error Scoring System (LESS) tests were recorded as subjects' performance scores. The kinematic variables of the subjects' lower limbs were measured by two cameras from the sagittal and frontal views during the Tuck Jump and LESS tests, before and after DNS exercises. The functional error of the subjects was recorded using the Kinovea software and recorded in the special table for scoring the tests. The subjects of the experimental group participated in the program of DNS exercises for 6 weeks and 3 sessions per week (each session lasting about 50 minutes). In order to analyze the data, independent and dependent parametric t-tests were used for data with normal distribution, and Mann Whitney U and Wilcoxon non-parametric tests were used for data with non-normal distribution in SPSS version 23 software.

The findings of the current research showed that DNS exercises was led to a significant decrease in the average Tuck Jump errors from 10.66 in the pre-test to 7.80 in the post-test (p=0.001), the score of the LESS from 8.13 in the pre-test to 4.53 in the post-test (p=-0.001) and the ligament dominance score decreased from 1.40 in the pre-test to 0.8 in the post-test (p=0.003) in the experimental group.

According to the results of the present study, it seems that performing DNS exercises in female volleyball players reduces the risk of injury and improves Motor-performance and is probably effective in the rehabilitation of athletes. Therefore, the use of DNS exercises in sports with frequent jumps and landings such as volleyball is recommended to prevent ACL injury.

The aim of this research was to compare the vertical, medial-lateral and anterior-posterior components of ground reaction force after anterior cruciate ligament reconstruction with the healthy individuals during walking.

This was an analytic cross sectional research. The participants of this research included 46 football and volleyball athletes, who were divided into two groups of individuals with anterior cruciate ligament reconstruction (ACLR) and healthy individuals. A force plate was employed to evaluate the components of the ground reaction force while walking.The data were statistically analysed using independent t test and SPSS version 16 software.

The results related to the vertical component of ground reaction force showed that the participants with anterior cruciate ligament reconstruction applied more force to the ground during heel strike and toe-off compared to healthy individuals, although the difference between the two groups was not significant (p=0.09 and p=0.35), but this difference was greater during heel strike. Likewise, the results related to the horizontal components of the ground reaction force showed that participants with anterior cruciate ligament reconstruction applied more force to the ground in all horizontal components of the ground reaction force, but the biggest difference between the two groups was in the first 20% of the stance phase and in the posterior (p<0.007) and lateral (p<0.02) directions. This difference between the two groups was significant.

The results of the research showed that the most important difference between the two groups occurred in the first 20% of the stance phase. Although among the 6 measured components, only the posterior (p < 0.007) and medial (p < 0.02) ground force components were significant.

The purpose of this research was to investigate the effect of eight weeks of cross-training on the intensity of electrical activities and the functional quality of the muscles of athletes with anterior cruciate ligament injury during walking.

This semi-experimental study utilized a pre-test/post-test design. The statistical population included the athletes from Qeshm Island and Bandar Abbas City (football and volleyball), who had at least six months since their anterior cruciate ligament reconstruction. In this research, there were 30 participants who were divided into two training groups and a control group. The average age of the training group was 24.15 ± 7.89 and the control group was 24.97 ± 7.18 years. The electrical activity of the muscles was measured by an electromyography device in two phases, 100 milliseconds before (in the swing phase) and 200 milliseconds after the contact of the foot with the ground (in the stance phase). Also, the force plate device was used to measure the functional quality of the muscles. Ground reaction force; GRF and center of pressure; COP fluctuations were measured from the time of foot contact with the ground to 200 milliseconds after contact (in the stance phase), before and after cross training. The data were analyzed using SPSS software, version 25 and Repeated Measures ANOVA.

In the swing phase (100 milliseconds before the heel strike), the electromyography data of the research showed that after a period of cross training, the electrical activity of all the selected muscles increased, but this increase was significant in the tibialis anterior(from 45.18 to 48.31 microvolts) (p=0.009), rectus femoris (from 38.54 to 40.17 microvolts) (p=0.004), and gluteus medius (from 29.18 to 33.50 microvolts) (p=0.005). Also, the results of examining the electrical activity of the muscles in the stance phase (200 milliseconds after the heel strike), showed that the intensity of the electrical activity of all muscles increased after a period of cross training, but this increase was significant,  in the anterior tibial (from 09 44.56 to 49.5 microV) (p=0.001), vastus medialis(from 48.00 to 56.58 microV) (p=0.004), rectus femoris (from 45.18 to 48.31 microV) (p=0.02), biceps femoris (from 40.54 to 48.74 μV) (p=0.007) and gluteus medius (from 34.09 to 39.17 μV) (p=0.01). The results of the data related to moror control, (including the components of the ground reaction force and the fluctuations of the center of pressure from the time of the heel strike to 200 milliseconds later) after a period of cross training, a significant reduction has been shown in the vertical components (from 16 123.75 to 113.75 percent of weight in kilograms) (p=0.001), and the posterior component of the ground reaction force (from 23.12 to 19.15 percent of weight in kilograms) (p=0.002), and also in the fluctuations of the pressure center in the lateral direction (from 1.39 to 1.18 mm/s) (p=0.004) and the anterior direction (from 1.32 to 1.52 mm/s) (p=0.001).

Cross- training has been able to create changes in the injured leg through positive neuroplasticity in the motor cortex of the brain, which not only increases muscle activity, but also improves the quality and control of movement. It is suggested for sports injury and rehabilitation specialists to positively transfer the quality of movement to the injured leg It is suggested for sports injury and rehabilitation specialists to positively transfer the quality of movement to the injured leg. These exercises can be used to prevent anterior cruciate ligament injury and also in the initial time after the injury )when the person is unable to move the injured leg( or even after months of the injury.