Isabella Annoni

Effect of Leg Dominance on The Center-of-Mass Kinematics During an Inside-of-the-Foot Kick in Amateur Soccer Players

Abstract Soccer kicking kinematics has received wide interest in literature. However, while the instep-kick has been broadly studied, only few researchers investigated the inside-of-the-foot kick, which is one of the most frequently performed techniques during games. In particular, little knowledge is available about differences in kinematics when kicking with the preferred and non-preferred leg. A motion analysis system recorded the three-dimensional coordinates of reflective markers placed upon the body of nine amateur soccer players (23.0 ± 2.1 years, BMI 22.2 ± 2.6 kg/m2), who performed 30 pass-kicks each, 15 with the preferred and 15 with the non-preferred leg. We investigated skill kinematics while maintaining a perspective on the complete picture of movement, looking for laterality related differences. The main focus was laid on: anatomical angles, contribution of upper limbs in kick biomechanics, kinematics of the body Center of Mass (CoM), which describes the whole body movement and is related to balance and stability. When kicking with the preferred leg, CoM displacement during the ground-support phase was 13% higher (p<0.001), normalized CoM height was 1.3% lower (p<0.001) and CoM velocity 10% higher (p<0.01); foot and shank velocities were about 5% higher (p<0.01); arms were more abducted (p<0.01); shoulders were rotated more towards the target (p<0.01, 6° mean orientation difference). We concluded that differences in motor control between preferred and non-preferred leg kicks exist, particularly in the movement velocity and upper body kinematics. Coaches can use these results to provide effective instructions to players in the learning process, moving their focus on kicking speed and upper body behavior

Dribbling determinants in sub-elite youth soccer players

Abstract Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s−1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.

Three-dimensional motion analysis of facial movement during verbal and nonverbal expressions in healthy subjects.

Functional impairments of facial expressions alter the quality of life and their quantitative analysis is key to describing and grading facial function and dysfunction. The aim of this investigation was to quantify 3D lip movements in a group of healthy young subjects. Lip movements during five repetitions of common and random sequences of vowels and nonverbal expressions were recorded using an optoelectronic 3D motion analyzer. The mean maximum displacement of facial landmarks was used to compute 3D unilateral mobility and the symmetry indices (SI) separately for each sex. Facial mobility was significantly greater during open‐mouth than closed‐mouth smiles. Facial movement among the subjects was largest during articulation of the vowel /a/ and smallest for /i/. Lips were pursed with a SI very close to 95%, while smiles were slightly more asymmetric. The vowel /a/ was articulated with significantly greater symmetry than /e/, /i/ and /u/. The outcomes suggest that the proposed method characterized normal facial animations satisfactorily, so it could be a useful tool for assessing patients with facial lesions and dentofacial deformities. Patient assessment would profit from this quantitative approach, which would reduce discrepancies among several clinical examinations. Clin. Anat. 29:991–997, 2016.

Morphological and functional facial asymmetry in patients with mild temporomandibular disorders: a pilot study

Facial asymmetry is normal in humans[1]. Authors indicated that facial asymmetry could influence the shape and function of the temporomandibular joints and vice versa[2]. In this study we collected preliminary reference values for facial asymmetry in adults with temporomandibular disorders (TMD), compared to a control group, using a 3D stereophotogrammetric imaging system and electromyographic (EMG) indices. Forty subjects (22 TMD; 18 control; paired for age: 21±2y) were recruited. Five linear measurements for each hemiface and asymmetry index (AI%) were computed from stereophotogrammetric scans. Standardized EMG indices for masseter and temporal muscles were obtained during clenching and gum chewing. Means of control and TMD groups were compared by t-test. For both groups, the AI for all linear measurements ranged from -10% to +10%; there was a great variability, especially for TMD group, who showed the higher values. For EMG indices, TMD group demonstrated a tendency to a more asymmetric muscular recruitment in static activities (masseter & temporal symmetry, C 87.5±1.76%; TMD 84.6±6.2%; p=0.06) and reduced symmetry during gum chewing (C 67.1± 20.9%; TMD 55.0±18.1%; p=0.06). The presence of higher asymmetry for stereophotogrammetry and EMG analyses, as well as the presence of alterations of masticatory function for the TMD group, suggest that this relationship should be further investigated. An analysis with a larger sample and with more severe TMD patients, together with a longitudinal study, is required to understand these possible relationships between morphology and function.

Body center of mass displacements during walking with low- and high-heeled shoes

Walking is a natural activity that is very often performed wearing shoes. Among many other kinds of footwear, high-heeled shoes induce increased ankle plantar flexion, greater knee flexion, anterior pelvic tilt, and trunk extension [1]. The modifications in the arrangement of body segments cause an altered position of the body centre of mass (CoM). In the current study, we quantitatively compared the 3D displacement of CoM during flat-heeled and high-heeled gait. Eleven volunteer women (mean age, 24 years) walked wearing either low-heeled and high-heeled shoes (minimum height, 70 mm). On each subject, the 3D coordinates of 14 body landmarks were recorded by an optoelectronic motion analyzer. The body was segmented in 10 independent masses: head, torso, two upper arms and two lower arms (upper body); two upper legs and two lower legs (lower body). Using mean anthropometric data, the whole body CoM was computed, as well as its superior (uCoM) and inferior (iCoM) components [2]. The body CoM was evaluated during normalized stride cycles. High-heeled gait, compared to flat-heeled gait, had a significantly lower CoM at Right heel strike (p=0.024) and Left heel strike (p=0.030). The same findings were also observed for uCoM and iCoM. No significant differences were found at Right toe off. In addition, a significant forward displacement of the iCoM in high-heeled gait was observed at each of the three stages (R heel strike, p=0.017; L heel strike, p=0.034; R toe off, p=0.003). Similar results were found for the whole CoM (p=0.024, p=0.038, p=0.004). The uCoM in high-heeled gait, instead, was significantly more anterior than in flat-heeled gait only at R toe off (p=0.024). Our findings confirmed that wearing high-heeled shoes significantly alters the normal displacement of both components of the human CoM.

Does physical fitness affect the locomotion kinematics of lower limbs in healthy adults

It is well known that obese and elderly subjects show modifications in joint range of motion (ROM) and spatio-temporal gait parameters. This is presumably due to a reduction in muscle strength and flexibility [1], but there are few quantitative studies that objectively measure the influence of physical performance on gait pattern. In this study, we investigated if different levels of strength and flexibility could affect the kinematics of lower limbs in a group of healthy adults. Sixteen normalweight subjects (age, 27.1±5.0 yr; BMI, 22±2.1 kg/m2; preferred walking speed 5.5±0.5 km/h) performed an isometric maximal voluntary contraction (iMVC) on a horizontal leg press equipped with two force plates. The V-sit and reach test was used to assess flexibility. An optoelectronic system was used to measure kinematics while subjects performed 10 min of treadmill walking at 5.5 km/h. We calculated the main spatio-temporal parameters, the ROM and the angular values of pelvis and lower limbs joints at heel strike and toe off events. To find possible associations between physical fitness and biomechanical values, we used the stepwise backward logistic regression analysis, adjusted for age, height and weight. Significant negative associations were identified between iMVC and knee angle at heel strike (F=7.831, p<0.01). Pelvic rotation ROM (F=7.31, p<0.01), knee ROM (F=5.061, p<0.05) and plantarflexion at heel strike (F=4.154, p<0.05) were positively associated with iMVC, as much as flexibility with hip extension at toe off (F=4.355, p<0.05). We found that, in accord with Ko et al. [2], the maximum knee extensor strength was related to modifications of knee ROM. In conclusion, it seems that even in adulthood, different values of strength and flexibility could affect some components of gait kinematics.

Maximum voluntary clenching and unilateral chewing in patients with mild-moderate TMD

Temporomandibular disorders (TMD) consist of a number of clinical problems that involve the masticatory muscles, the temporomandibular joint and associated structures. The aim of the study was to quantitatively compare electromyographic (EMG) parameters of patients with mild-moderate TMD and healthy subjects. Twenty patients with mild-moderate TMD (5 men, 15 women, 22–56 y) and 19 healthy subjects (9 men, 10 women, 21–49 y) were analyzed. sEMG of the left and right masseter and temporalis anterior muscles was recorded using a wireless device (TMJoint, BTS, Italy). Each subject performed a 5 s-maximum voluntary contraction (MVC) with the teeth in intercuspal position (CLENCH), and one with two 10 mm-thick cotton rolls positioned on the mandibular second premolars/first molars (COT). EMG activity was further recorded during unilateral, right and left, gum chewing. EMG potentials of both MVC and chewing were standardized as percentages of the potentials obtained during COT recording [1]. During MVC, EMG activities were less symmetric and had a larger torque component in TMD patients than in healthy subjects (muscular asymmetry: 10.4±9.1% vs 4.4±4.2%, Student’s t-test, p=0.013; torque: 9.8±10.9% vs 4.4±4.0%, p=0.047). During chewing, all healthy subjects had a good coordination between masseter and temporalis contractions, with a prevalent activity of the working-side muscles. Among TMD patients, instead, 9 subjects performed at least one of their unilateral chewing tests with an altered muscular coordination. EMG activity of TMD patients was less coordinated than that of healthy subjects, with a larger variability between chewing cycles (Hotelling’s ellipse area: 2275±2734% vs 1010±845%, Student’s t-test, p=0.061). sEMG analysis could be a useful tool to detect functionally altered stomatognathic muscular coordination. Dote ricerca: FSE, Regione Lombardia

Facial movements during verbal and not verbal activities: an optoelectronic 3D study

Functional impairments of facial movements alter the quality of life, and their quantitative analysis is a key step in the description and grading of facial function and dysfunction. In this investigation we assessed the symmetry of lip movements in verbal and non verbal movements in healthy subjects. Fifteen healthy young adults (aged 24.7±4.6 y) were analysed using a 3D motion analyzer (SMART-E, BTS, Italy). All subjects had a clinically normal facial function. For each subject, 11 soft tissue landmarks were identified by a set of 5-mm round reflective markers: n, nasion; ft, right and left frontotemporale; ng, right and left naso-genian; cph, right and left crista philtri; ch, right and left cheilion; li, right and left lower lip midpoints. Each subject performed five standardized, maximum labial animations from rest: open mouth smile (OS); closed mouth smile (CS); spontaneous smile (SS); lip pursing (LP); vowels pronunciation. Ten repetitions of each expression were recorded without modifications of the marker positions. The total 3D mobility of right and left sides (unit: mm) was computed during smile animations (OS: 42±11.1 vs 44.1±10.8; CS: 30.5±11.4 vs 33.1±12.3; SS: 38.8±13.7 vs 39.5±12.7), lip purse (35.1±5.8 vs 34.9±7.1) and vowels pronunciation (a: 33.8±9.5 vs 33.4±11.2; e: 21.4±8.1 vs 21±9.4; i: 15.4±5.2 vs 15.4±5.7; o: 23.2±7.6 vs 22.2±6.6; u: 20.8±6.5 vs 18.8±6.2). The movements were symmetric (no significant differences were found, Student’s t-paired test, p>0.05). Additionally, the asymmetry indices of labial landmark displacement [1] were not significantly different from 0 in both not-verbal (OS: 2.9%; CS: 4.3%; SS: 3.5%; LP: 0.7%) and verbal (a: 1.2%; e: 1.7%; i: 0.5%; o: 1.7%; u: 5.2%) activities. In conclusion, in healthy young adults standardized labial movements were performed with similar mobility between right and left sides. Data will be used for the quantitative assessment of the impairments of patients with facial lesions.

Three-dimensional analysis of jaw movements during unilateral gum chewing in healthy subjects and patients with temporomandibular disorders

In our laboratory, we are currently analyzing three-dimensional mandibular movements during the performance of physiological movements. The aim of the current investigation was to quantitatively compare the three-dimensional jaw movement of healthy subjects and patients with temporomandibular disorders (TMD) performing standardized unilateral gum chewing. Mandibular movements were non-invasively detected and recorded using an optoelectronic motion analyzer, with a 60 Hz sampling rate. Ten healthy subjects (mean age 32 y, SD 16 y) and ten subjects with mild or moderate TMD signs and symptoms (mean age 27 y, SD 8 y) chewed a gum alternatively on the right (R) and left (L) side of the mouth. Nine passive markers (diameter 5 mm) were used: three created a cranial reference system; three positioned on a stainless steel extraoral frame fixed on the mandibular anterior gingival, provided the mandibular reference system; two individualized the cutaneous projections of the R and L condyles, and one corresponded to the interincisal point. For both the healthy and TMD groups, the three-dimensional pathway of the interincisal reference point was evaluated in 16 chewing cycles on each side of the mouth. On average, the area covered by the interincisal point was similar (2-way ANOVA, p > 0.05) during R and L chewing in both healthy (frontal plane, 21.1±13.5 vs. 22±11.1 mm 2 ; sagittal plane, 9.4±4.8 vs. 9.4±3.8 mm 2 ) and TMD groups (frontal plane, 15.7±9.3 vs. 19.6±10.2 mm 2 ; sagittal plane, 11.3±6.1 vs. 9.3±5.9 mm 2 ). The interincisal point velocity during the closing phase was greater than during the opening phase (3-way ANOVA, p < 0.001), regardless of side in both healthy and TMD groups (respectively: R chewing opening, 3.3±1.1 vs. 3.4±0.6 cm/s; R chewing closing 4.5±1.6 vs. 4.6±0.9 cm/s; L chewing opening, 3.5±0.8 vs. 3.5±0.7 cm/s; L chewing closing, 5.0±1.6 vs. 4.5±1.2 cm/s). The morphological analysis of the frontal plane chewing patterns revealed a higher frequency of altered patterns 1 in the TMD group than in the control subjects (Chi-square, p < 0.01). These findings showed that, in TMD patients, the chewing-cycle kinematics is not different from the normal subjects. Anyway the presence of a higher frequency of altered cycles suggests that TMD can influence the masticatory pattern, even in mild or moderate TMD patients. 1. Takeda et al. J Oral Maxillofac Surg. 2009;67:1844-9.