Quadriceps femoris cross-sectional area and specific leg strength: relationship between different muscles and squat variations

Background The aim was to determine the relationship between the cross-sectional area of the quadriceps femoris and strength performance in the deep and parallel barbell squat. Methods The sample included 16 university students (seven female, 24.1 ± 1.7 years). Muscle strength was expressed as external load, including the one-repetition maximum and the body mass segments involved (calculated according to Dempster’s method). The cross-sectional area of the quadriceps femoris muscles was determined using ultrasound, while leg muscle mass was measured using the Bioelectrical Impedance method. Results The cross-sectional areas of the three vastii muscles and leg muscle mass showed moderate to strong correlation with external load in both squat types (r = 0.509–0.873). However, partial correlation (cross-sectional area of quadriceps femoris muscles were controlled) showed significant association only between leg muscle mass and deep squat (r = 0.64, p < 0.05). The cross-sectional area of the vastus lateralis showed a slightly higher correlation with external load in the parallel than in the deep squat (r = 0.67, p < 0.01 vs. r = 0.59, p < 0.05). The regression analysis extracted the vastus medialis cross-sectional area as the most important factor in manifesting strength (parallel squat: R2 = 0.569; deep squat: R2 = 0.499, both p < 0.01). The obtained results suggest that parallel squat strength depends mainly on the cross-sectional area of the vastii muscles, while it seems that the performance in the deep squat requires an additional engagement of the hip and back extensor muscle groups.

Effects of a preparatory training protocol on the movement and body stability of handball players

Handball is a sport with a high risk of injury, The prevalence of injury is only obtainable through a thorough and comprehensive analysis. One of the most commonly used test batteries for interpreting the characteristics of an injury is the Functional Movement Screen (FMSTM). It makes possible to possible to identify movement limitations and asymmetries which are believed to impact injury risk in sports. The aim of this study is to use the FMSTM to determine whether an eight-week training protocol can predict and prevent injuries in handball. The study sample comprised the fifteen members of the Borac handball club youth team. The initial measurement showed that most players (80%) had an overall score in the test battery ranging from 15 to 20 points. In addition, three players were found to have asymmetry. Only one of the three players had an overall score in the FMSTM of ≤14. The participants scored the lowest in the initial measurement for Rotary Stability, followed by Deep Squat and Hurdle Step Left. They scored the highest in the Shoulder Mobility. After the implementation of the exercise protocol for improving body mobility and stability, the final measurements showed that all the participants had an overall score in the FMSTM of >14. The value of eta squared showed that training in between the two measurements had a significant impact. At the time of testing and protocol implementation no players sustained any injuries during matches or in training. This study confirmed that the FMSTM can be used to predict injuries in sports.

The Level of the Functional Movement Screen Among Traditional Dancers

Movement assessments are commonly used to assess athlete&rsquo;s risk of injury as well as basic and specific skill movement patterns; however, dance is identified to be differing from sports because the average dancer&rsquo;s training load is higher than the athletes. This study aims to identify the difference in the Functional Movement Screen (FMS) level among traditional dancers in Malaysia. A quasi-experimental study design was adopted, which involved 66 dancers (M = 33; F = 33). The study comprised traditional dancers from three ethnic backgrounds, namely, Malay, Chinese and Indian. The descriptive analysis described the level of the dancers&rsquo; FMS, as follows: Malay (M = 16.18, SD = 2.062), Chinese (M = 18.50, SD = 1.102), Indian (M = 18.23, SD = 1.445). The ANOVA analysis found a significant difference in the FMS scores among all three groups of dancers, F (2,63) = 14.026, p &gt;.000. The deep squat, hurdle step, shoulder mobility, active straight leg raise and trunk stability tests for push-up indicated a significant difference, whereas the inline lunges test and rotational stability tests showed no significance difference. However, the Post Hoc analysis showed no significant difference between the Chinese and Indian dancers. It can be concluded that there is a difference in FMS scores between Malay, Chinese and Indian dancers. FMS may be a useful tool to help identify dancers about the risk of injury and improve their movement quality.

Assessing Movement Quality in Youth Footballers: The Relationship between Hip and Lower Limb Movement Screen and Functional Movement Screen

The Hip and Lower Limb Movement Screen (HLLMS) was developed to detect altered movement patterns and asymmetry specifically related to hip, pelvic, and lower limb movement control, as the other tools, such as the Functional Movement Screen (FMS), lacked focus on the hip and pelvic area. Both screening tools contain symmetrical and asymmetrical motor tasks which are based on observation of different aspects of each task performance. One motor task is in both screening tools. Therefore, they have some common features. The present study aimed to assess the relationship between the HLLMS and FMS performance in youth football players. The study included 41 elite male football (soccer) players (age: 15.6 ± 0.50 years), and the HLLMS and FMS scores were analyzed by assessing Spearman’s rank correlation. The FMS total score and the FMSMOVE were moderately correlated with the HLLMS total score (R = −0.54; −0.53, respectively). The FMS rotatory stability task was moderately correlated with the HLLMS small knee bend with the trunk rotation task (R = −0.50). The FMS deep squat task was moderately correlated with the HLLMS deep squat task (R = −0.46). The FMS hurdle step was weakly correlated with two of the HLLMS tasks: standing hip flexion (R = −0.37) and hip abduction with external rotation (R = −0.34). There were no other relationships found (p > 0.05). Out of the seven FMS tasks, only one asymmetrical (trunk rotary stability) and one symmetrical (deep squat) task were moderately related to the newly developed HLLMS tool contributing moderate relationship between the FMS total score and the HLLMS total score. Other FMS tasks were weakly or unrelated with the HLLMS. These findings indicate that these two screening tools mainly assess different aspects of movement quality in healthy youth football players.

Comparison of Lower Extremity Kinematics during the Overhead Deep Squat by Functional Movement Screen Score

It is unclear if the Functional Movement Screen (FMS) scoring criteria identify kinematics that have been associated with lower extremity injury risk. The purpose was to compare lower extremity kinematics of the overhead deep squat (OHDS) during the FMS between individuals who were grouped on FMS scoring. Forty-five adults who were free of injury and without knowledge of the FMS or its scoring criteria (males = 19, females = 26; height = 1.68 0.08 m; mass = 70.7 7 13.0 kg). Three-dimensional lower extremity kinematics during an OHDS were measured using a motion capture system. One-way MANOVA was used to compare kinematic outcomes (peak hip flexion angle, hip adduction angle, knee flexion angle, knee abduction angle, knee internal rotation angle, and ankle dorsiflexion angle) between FMS groups. Those who scored a 3 had greater peak hip flexion angle (F2,42 = 8.75; p = 0.001), knee flexion angle (F2,42 = 13.53; p = 0.001), knee internal rotation angle (F2,42 = 12.91; p = 0.001), and dorsiflexion angle (F2,42 = 9.00; p = 0.001) compared to those who scored a 2 or a 1. However, no differences were found in any outcome between those who scored a 2 and those who scored a 1, or in frontal plane hip or knee kinematics. FMS scoring for the OHDS identified differences in squat depth, which was characterized by larger peak hip, knee, and dorsi- flexion angles in those who scored a 3 compared with those who scored 2 or 1. However, no differences were found between those who scored a 2 or 1, and caution is recommended when interpreting these scores. Despite a different FMS score, few differences were observed in frontal or transverse plane hip and knee kinematics, and other tasks may be needed to assess frontal plane kinematics.

Muscle and Hip Contact Forces in Asymptomatic Men With Cam Morphology During Deep Squat

Cam morphology is defined as an aspherical femoral head-neck junction that causes abnormal contact of the acetabular rim with the anterior hip. Imaging confirmation of the cam morphology, associated with clinical signs and pain in the hip or groin, is characterized as femoroacetabular impingement (FAI) syndrome. Although some individuals with cam morphology do not experience any symptoms, sparse studies have been done on these individuals. Understanding the way asymptomatic individuals generate muscle forces may help us to better explain the progression of the degenerative FAI process and discover better ways in preventing the onset or worsening of symptoms. The purpose of this study was to compare the muscle and hip contact forces of asymptomatic cam morphology (ACM) and FAI syndrome men compared to cam-free healthy controls during a deep squat task. This prospective study compared 39 participants, with 13 in each group (ACM, FAI, and control). Five deep squatting trials were performed at a self-selected pace while joint trajectories and ground reaction forces were recorded. A generic model was scaled for each participant, and inverse kinematics and inverse dynamics calculated joint angles and moments, respectively. Muscle and hip contact forces were estimated using static optimization. All variables were time normalized in percentage by the total squat cycle and both muscle forces and hip contact forces were normalized by body weight. Statistical non-parametric mapping analyses were used to compare the groups. The ACM group showed increased pelvic tilt and hip flexion angles compared to the FAI group during the descent and ascent phases of the squat cycle. Muscle forces were greater in the ACM and control groups, compared to the FAI group for the psoas and semimembranosus muscles. Biceps femoris muscle force was lower in the ACM group compared to the FAI group. The FAI group had lower posterior hip contact force compared to both the control and ACM groups. Muscle contraction strategy was different in the FAI group compared to the ACM and control groups, which caused different muscle force applications during hip extension. These results rebut the concept that mobility restrictions are solely caused by the presence of the cam morphology and propose evidence that symptoms and muscle contraction strategy can be the origin of the mobility restriction in male patients with FAI.