scholarly journals Which of the five classical ballet positions is the most demanding for the dancer’s body? An electromyography-based study to determine muscular activity

2020 ◽  
Vol 22 (4) ◽  
Author(s):  
Joanna Gorwa ◽  
Jarosław Kabaciński ◽  
Michał Murawa ◽  
Anna Fryzowicz

Purpose: The study aimed to determine which of the five classical ballet positions is the most demanding regarding muscular activity, values of external rotation in the hip joints, angular values of foot progression as well as the inclination (tilt) of the pelvis in the sagittal plane. Methods: In this cross-sectional study, 14 female pre-professional ballet dancers (aged 11–16) participated. Participants were tasked with the sequential adoption of five classical ballet positions (CP1–CP5). The electromyographic activity of the muscles of the trunk and the lower limb was recorded with surface electrodes. Kinematic data including hip and knee external rotation, foot progression angle and pelvic tilt were collected using a motion capture system. Results: Symmetric positions CP1 and CP2 were not as demanding as asymmetric CP3–CP5. Higher values of hip and foot external rotation without greater muscular effort in CP2 than CP1 was noticed. Considering asymmetric positions, CP3 did not trigger a greater activity of hip or foot muscular groups than CP4 and CP5. CP4 was characterised by the greatest pelvic anterior tilt and the lowest activity of GM in the forward lower limb. In CP5, forward lower limb entailed a higher activity of muscles supporting the foot than in the remaining positions. Conclusion: In terms of biomechanics, the most demanding classical ballet position in pre-professional dancers is CP4, followed by CP5, CP3, CP1 and CP2. This finding can be applied in educational methodology of dancers, figure skaters, synchronized swimmers, acrobatic gymnasts, rhythmic gymnasts or cheerleaders.

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Massimiliano Pau ◽  
Bruno Leban ◽  
Michela Deidda ◽  
Federica Putzolu ◽  
Micaela Porta ◽  
...  

The majority of people with Multiple Sclerosis (pwMS), report lower limb motor dysfunctions, which may relevantly affect postural control, gait and a wide range of activities of daily living. While it is quite common to observe a different impact of the disease on the two limbs (i.e., one of them is more affected), less clear are the effects of such asymmetry on gait performance. The present retrospective cross-sectional study aimed to characterize the magnitude of interlimb asymmetry in pwMS, particularly as regards the joint kinematics, using parameters derived from angle-angle diagrams. To this end, we analyzed gait patterns of 101 pwMS (55 women, 46 men, mean age 46.3, average Expanded Disability Status Scale (EDSS) score 3.5, range 1–6.5) and 81 unaffected individuals age- and sex-matched who underwent 3D computerized gait analysis carried out using an eight-camera motion capture system. Spatio-temporal parameters and kinematics in the sagittal plane at hip, knee and ankle joints were considered for the analysis. The angular trends of left and right sides were processed to build synchronized angle–angle diagrams (cyclograms) for each joint, and symmetry was assessed by computing several geometrical features such as area, orientation and Trend Symmetry. Based on cyclogram orientation and Trend Symmetry, the results show that pwMS exhibit significantly greater asymmetry in all three joints with respect to unaffected individuals. In particular, orientation values were as follows: 5.1 of pwMS vs. 1.6 of unaffected individuals at hip joint, 7.0 vs. 1.5 at knee and 6.4 vs. 3.0 at ankle (p < 0.001 in all cases), while for Trend Symmetry we obtained at hip 1.7 of pwMS vs. 0.3 of unaffected individuals, 4.2 vs. 0.5 at knee and 8.5 vs. 1.5 at ankle (p < 0.001 in all cases). Moreover, the same parameters were sensitive enough to discriminate individuals of different disability levels. With few exceptions, all the calculated symmetry parameters were found significantly correlated with the main spatio-temporal parameters of gait and the EDSS score. In particular, large correlations were detected between Trend Symmetry and gait speed (with rho values in the range of –0.58 to –0.63 depending on the considered joint, p < 0.001) and between Trend Symmetry and EDSS score (rho = 0.62 to 0.69, p < 0.001). Such results suggest not only that MS is associated with significantly marked interlimb asymmetry during gait but also that such asymmetry worsens as the disease progresses and that it has a relevant impact on gait performances.


2017 ◽  
Vol 52 (7) ◽  
pp. 643-648 ◽  
Author(s):  
Catherine Y. Wild ◽  
Avril Grealish ◽  
Diana Hopper

Context:  Because of the increasing popularity of participation in Irish dance, the incidence of lower limb injuries is high among this competitive population. Objective:  To investigate the effects of fatigue on the peak lower limb and trunk angles as well as the peak lower limb joint forces and moments of competitive female Irish dancers during the performance of a dance-specific single-limb landing. Design:  Cross-sectional study. Setting:  Laboratory. Patients or Other Participants:  Fourteen healthy, female, competitive Irish dancers (age = 19.4 ± 3.7 years, height = 165.3 ± 5.9 cm, mass = 57.9 ± 8.2 kg). Intervention(s):  Participants performed an Irish dance–specific leap before and after a dance-specific fatigue protocol. During each landing movement, 3-dimensional lower limb kinematics (250 Hz) and ground reaction forces (1000 Hz) were collected. Paired t tests were performed to determine the differences (P ≤ .05) in lower limb and trunk biomechanics prefatigue and postfatigue. Main Outcome Measure(s):  Peak lower limb and trunk angles as well as peak lower limb joint reaction forces and external moments. Results:  Compared with the prefatigue trials, dancers landed with reduced ankle plantar flexion (P = .003) and hip external rotation (P = .007) and increased hip-adduction alignment (P = .034) postfatigue. Dancers displayed greater anterior shear (P = .003) and compressive (P = .024) forces at the ankle and greater external knee-flexion moments (P = .024) during the postfatigue compared with the prefatigue landing trials. Conclusions:  When fatigued, dancers displayed a decline in landing performance in terms of aesthetics as well as increased ankle- and knee-joint loading, potentially exposing them to a greater risk of injuries.


2017 ◽  
Vol 41 (6) ◽  
pp. 579-586 ◽  
Author(s):  
Tulaya Prachgosin ◽  
Wipawan Leelasamran ◽  
Pruittikorn Smithmaitrie ◽  
Surapong Chatpun

Background: Total-contact orthosis (TCO) is one kind of foot orthosis (FO) that is used to adjust biomechanics in flexible flatfoot. Objective: To determine the effects of a TCO on the MLA moment, MLA deformation angle and lower limb biomechanics. Study Design: Cross-sectional study. Methods: Seven-flatfoot and thirteen-normal foot subjects were recruited by footprint and radiographs. The biomechanics of subjects with normal foot (NF), flatfoot with shoe only (FWOT) and flatfoot with TCO (FWT) were collected in a 3D motion analysis laboratory and force plates. The MLA and lower limb biomechanics in each condition during specific sub-phases of stance were analyzed. Results: The NF had larger MLA eversion moment after shod walking ( p = 0.001). The FWT condition compared with the FWOT condition had a significantly larger peak MLA upward moment ( p = 0.035) during pre-swing, larger peak knee external rotation angle ( p = 0.040) during mid stance, smaller peak knee extension moment during terminal stance ( p = 0.035) and a larger ground reaction force in the anterior-posterior direction during early stance ( p < 0.05). Conclusion: Our study found positive effects from the customized TCOs which included an increased TCO angle that led to a decreased peak MLA moment in the frontal plane in flexible flatfoot subjects during walking. Clinical relevance Lower limb biomechanics is different from normal in subjects with flexible flatfoot. The design of a TCO affects MLA, ankle and knee biomechanics and may be used to clinically correct biomechanical changes in flexible flatfoot.


Author(s):  
Tripta S. Bhagat ◽  
Luv Kumar ◽  
Prakhar Garg ◽  
Apoorv Goel ◽  
Amit Aggarwal ◽  
...  

Cellulitis is a bacterial infection of the dermis and subcutaneous tissues occupying a large proportion of hospital beds. This study was conducted for analysis of patients with cellulitis according to their demographics and clinical presentation and to examine their comorbidities, complications, and its management. This observational cross-sectional study was conducted in the Department of Surgery at Santosh Medical College and Hospitals involving a total of 60 cases having cellulitis and other soft tissue infections of lower limb. Analysis of their demographic profile, management, and complications was done. Cellulitis is seen commonly in males, 46 (76.6%). The mean age of patients affected by cellulitis in the study was 36.4 ± 1.23 years. The most common site affected is leg involving more people in field jobs. The most common risk factor was trauma in 46.6%, and other factors were diabetes mellitus and smoking, while abscess formation was the most common complication observed in 36.6% of cases. A total of 56.6% cases were managed conservatively, while 43.3% cases required surgical intervention. Mean hospital stay in this study was 5.02 ± 0.23 days. It was concluded that cellulitis is subcutaneous, spreading bacterial infection is more common in males, and its incidence is highest in working age group population. Lower limb is commonly involved. Trauma, smoking, and diabetes are significant risk factors for development of cellulitis. Abscess is the most common complication. About 50% patients with cellulitis can be managed conservatively and the rest require surgical intervention.


2018 ◽  
Vol 6 (1) ◽  
pp. 232596711775081 ◽  
Author(s):  
Jacopo Preziosi Standoli ◽  
Francesco Fratalocchi ◽  
Vittorio Candela ◽  
Tiziano Preziosi Standoli ◽  
Giuseppe Giannicola ◽  
...  

Background: Overhead athletes are at a greater risk of developing scapular dyskinesis (SD). Although swimming is considered an overhead sport, information regarding SD in these athletes is scarce. Purpose: To determine the prevalence of SD in young, asymptomatic elite swimmers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 661 asymptomatic elite swimmers were enrolled in this study (344 male, 317 female; mean age, 15.83 ± 2.20 years). Anthropometric characteristics, training routine, and stroke specialty were recorded. SD was assessed using a dynamic test consisting of an examination of the shoulder blades throughout synchronous forward flexion motion in the sagittal plane and was deemed to be either present or absent. Each movement was repeated 5 times. These evaluations were performed with athletes at rest, before any training or competition. Statistical analysis was performed. Results: SD was detected in 56 (8.5%) participants. Type I SD was the most common (46.5%); male participants were 2 times as likely to have SD as female participants (39 male, 17 female; P < .01). No correlation was found between the dominant limb and side affected ( P = .258); rather, a correlation was found between the breathing side and side affected, in that swimmers with a preferred breathing side were more prone to develop SD in the opposite shoulder ( P < .05). Swimmers involved in long-distance races were found to have a greater risk of developing SD ( P = .01). Conclusion: SD may be an asymptomatic condition in elite young swimmers and is present in 8.5% of these athletes. Early diagnosis may be useful for asymptomatic athletes with SD and to avoid its possible evolution to a symptomatic condition.


2021 ◽  
pp. 2150019
Author(s):  
Andriana Koufogianni ◽  
Asimakis K. Kanellopoulos ◽  
Konstantinos Vassis ◽  
Ioannis A. Poulis

Design: Cross-sectional study. Background: Osteoarthritis is one of the most common conditions in our society. A growing number of studies suggest the existence of central sensitization (CS) in a subgroup of osteoarthritic patients. One of the criteria included for the classification of CS pain is the expanded distribution of pain. As this criterion is a well-recognized sign of CS, a digital pain drawing (DPD) analysis would be useful to easily identify possible extended areas of pain distribution (PD) in patients with OA. Objective: To study the relationship between the percentage of distribution of pain in the lower limb for both knee and hip, in patients before hip or knee arthroplasty, and the Central Sensitization Inventory Questionnaire. Methods: Twenty women (mean [Formula: see text] years) with diagnosed chronic (over 3 months) knee ([Formula: see text]) and hip ([Formula: see text]) OA participated in the study, with intensity of pain from mild to severe, meaning pain [Formula: see text]/10 using the Numeric Pain Rating Scale (NPRS). The PD was analyzed via software created for this research, called “Pain Distribution Application”. Results: A statistically significant positive correlation between CSI and PD to the lower extremity OA (hip and knee) ([Formula: see text], [Formula: see text]) was found. The distribution of pain has a linear correlation with the results in CSI, of patients who tested positive for CS, i.e. with a score of [Formula: see text]. Conclusions: As the distribution of pain on the surface of the body (diffusion) increases, so does the score of people who test positive for CSI. Our results showed that calculating the distribution of pain with our application may have a utility as a CS screening tool. The PD threshold of 10% of the body area is an index for CS for chronic pain lower limb OA patients.


2019 ◽  
Vol 28 (10) ◽  
pp. 2311-2318 ◽  
Author(s):  
Mariana Tedeschi Benatto ◽  
Lidiane Lima Florencio ◽  
Marcela Mendes Bragatto ◽  
Samuel Straceri Lodovichi ◽  
Fabíola Dach ◽  
...  

2020 ◽  
Vol 8 (10) ◽  
pp. 232596712095742
Author(s):  
Munif Hatem ◽  
Scott J. Nimmons ◽  
Anthony Nicholas Khoury ◽  
Hal David Martin

Background: The orientation of the acetabulum has a fundamental role in impingement and instability of the hip, and the spinopelvic parameters are thought to predict the sagittal orientation of the acetabulum (SOA). However, similar to the acetabular version (axial orientation) and inclination (coronal orientation), the cephalic or caudal orientation of the acetabulum in the sagittal plane, or SOA, may primarily be an intrinsic feature of the acetabulum itself. Purpose: To determine whether the spinopelvic parameters predict the sagittal orientation of the acetabulum in individuals without lumbar deformity. Study Design: Cross-sectional study; Level of evidence, 4. Methods: A retrospective analysis was performed in 89 patients (94 hips; 62 female, 27 male; mean ± SD age, 45.9 ± 15.4 years) without lumbosacral deformity who underwent magnetic resonance arthrogram (MRA) for assessment of hip pain. The SOA was determined in the sagittal cut MRA. A line was drawn at the distal limit of the anterior and posterior acetabular horns longitudinally to the transverse ligament, and the angle between this line and the axial plane represented the SOA. The sacral slope, pelvic incidence, and spinopelvic tilt were determined using a 3-dimensional cursor and the axial, sagittal, and coronal cuts. All MRA studies were performed with the patient in the supine position. Results: The SOA had a mean ± SD cephalic orientation of 18° ± 6.6°. No significant correlation was observed between the SOA and the sacral slope ( r = –0.03; P = .77). A weak correlation was observed between the SOA and the pelvic incidence ( r = 0.22; P = .03) and between the SOA and the spinopelvic tilt ( r = 0.41; P < .01). Conclusion: The SOA cannot be presumed based on the spinopelvic parameter. Similar to the well-known parameters to assess the axial and coronal orientation of the acetabulum, the assessment of the SOA demands acetabular-specific parameters. Additional studies are necessary to assess the SOA in asymptomatic hips, including disparities between genders. Clinically significant values for abnormal SOA of the acetabulum remain to be defined.


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