scholarly journals Muscle Activation and Subjectively Perceived Effort in Typical Violin Positions

2021 ◽  
Vol 36 (3) ◽  
pp. 207-217
Author(s):  
Horst Hildebrandt ◽  
Oliver Margulies ◽  
Barbara Köhler ◽  
Marta Nemcova ◽  
Matthias Nübling ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Sagittal Plane ◽  
Longitudinal Axis ◽  
Borg Scale ◽  
Mean Values ◽  
Medicine Research ◽  
Perceived Effort ◽  
Musculoskeletal Problems ◽  
Medical Counseling ◽  
Violin Playing

Violinists display a high incidence of task-specific musculoskeletal problems. Sources pertaining to violin playing and teaching traditions as well as musicians’ medicine research offer only imprecise and contradictory recommendations regarding suitable instrument positions. The aim of this study was to add to a growing scientific base for teaching and medical counseling regarding violin positioning. The study evaluated muscle activation (EMG) and subjectively perceived effort (Borg scale) in four standardized typical violin positions, as well as the violinists’ normally used one. The hypothesis, the smaller the angle between the instrument’s longitudinal axis (LoAx) and the player’s central sagittal plane (CSP) and the angle between its lateral axis (LatAx) and the player’s horizontal plane (HP), the more muscle activation and perceived effort in the violinist’s left arm, was confirmed: Decreasing the LoAx-CSP angle from 50° to 20° and the LatAx-HP angle from 50° to 20° resulted in a highly significant and independent increase of EMG and Borg scale self-ratings mean values. Results may allow for a first step in decision-making on violin positioning for ergonomic adaptations in teaching as well as prevention and therapy of playing-related health problems at all levels of proficiency.

Evaluation of skin displacement in the equine neck

2014 ◽  
Vol 10 (3) ◽  
pp. 181-186 ◽  
Author(s):  
A. Bergh ◽  
A. Egenvall ◽  
E. Olsson ◽  
M. Uhlhorn ◽  
M. Rhodin
Keyword(s):  
Mixed Models ◽  
Sagittal Plane ◽  
Cervical Vertebrae ◽  
Statistical Significance ◽  
Longitudinal Axis ◽  
Joint Motion ◽  
Skin Marker ◽  
Significant Difference ◽  
Axis Parallel ◽  
Kinematic Studies

Kinematic studies, using reflective skin markers, are commonly used to investigate equine joint motion in equitation science and for rehabilitation purposes. In order to interpret the registrations accurately, the degree of skin displacement has been described for the limbs and back, but not yet for the neck. The aim of the present study was to measure sagittal plane skin displacement in the equine neck. Radiopaque skin markers were applied to the skin over the first six cervical vertebrae of six healthy horses. Latero-lateral radiographs were taken in three standardised neck positions in the sagittal plane: control (horizontal neck), ‘on the bit’ and ‘nose to carpus’. The scales of the images were normalised and calculation of skin displacement was done by use of a coordinate system, dividing the displacement along an x-axis parallel to the vertebra's longitudinal axis and a y-axis perpendicular to the x-axis. Mixed models analysis was employed to study the differences in distances in x- and y-directions, and statistical significance was set to PÃ0.05. Between control and ‘nose to carpus’ positions, there were significant differences in skin marker locations, relative to the underlying vertebrae, in the x-direction for C1-6, and in y-direction for C3-6. Between normal and ‘on the bit’ positions, there were significant difference in both x- and y-directions for C6. Differences in marker locations along x- and y-axes, respectively, were 3±9 mm and 44±14 mm. The outcome of this study indicates that skin displacement should be considered when investigating equine neck motion with skin marker methodology.

scholarly journals PARAMETERS FOR THE EVALUATION OF CERVICAL SAGITTAL BALANCE IN IDIOPATHIC SCOLIOSIS

2017 ◽  
Vol 16 (1) ◽  
pp. 38-41
Author(s):  
MAURICIO COELHO LIMA ◽  
MARCELO ITALO RISSO NETO ◽  
GUILHERME REBECHI ZUIANI ◽  
IVAN GUIDOLIN VEIGA ◽  
MARCOS ANTONIO TEBET ◽  
...  
Keyword(s):  
Idiopathic Scoliosis ◽  
Sagittal Balance ◽  
Sagittal Plane ◽  
Lateral View ◽  
Plumb Line ◽  
Cervical Lordosis ◽  
Thoracic Inlet ◽  
Mean Values ◽  
Cervical Sagittal Balance ◽  
The Mean

ABSTRACT Objective: There are no values defined as standard in the literature for the parameters of assessment of cervical sagittal balance in patients with idiopathic scoliosis. This study describes the sagittal cervical parameters in patients with idiopathic scoliosis. Methods: Study carried out in a tertiary public hospital in patients with adolescent idiopathic scoliosis, through the evaluation of panoramic radiographs in lateral view. The Cobb method was used to evaluate cervical lordosis from C2 to C7, distance from the center of gravity (COG) of the skull to C7, measurement of T1 slope, thoracic inlet angle (TIA), neck tilt, and plumb line from C7 to S1 (SVA C7-S1). A statistical analysis was performed, to demonstrate the relationship between the alignment of the thoracic spine in the sagittal plane and the cervical sagittal balance of patients with scoliosis. Results: Thirty-four patients were female (69.4%) and 15 male (30.6%). The mean values for COG-C7 were 0.71 mm (median 0.8 mm/standard deviation [SD]= 0.51 mm). For Cobb C2-C7, the mean was -11.7° (median -10°/SD= 20.4°). The mean slope of T1 was 23.5° (median 25°/SD= 9.5°). The mean cervical version was 58.8° (median 60°/DP= 15.4°). The mean TIA was 81.8° (median 85°/SD= 16.7°). The mean plumb line C7-S1 was -0.28 (-0.3/SD= 1.0). Conclusion: The analysis of the results showed that the mean values for the cervical lordosis are lower than the values described as normal in the literature, suggesting a loss of sagittal cervical balance in these patients.

Examination of the Origin and Branching Direction of the Anterior Medial Malleolar Artery From the Anterior Tibial Artery: A Cadaveric Study

2018 ◽  
Vol 12 (2) ◽  
pp. 167-171 ◽  
Author(s):  
Ichiro Tonogai ◽  
Fumio Hayashi ◽  
Yoshihiro Tsuruo ◽  
Koichi Sairyo
Keyword(s):  
Ankle Joint ◽  
Sagittal Plane ◽  
External Iliac Artery ◽  
Longitudinal Axis ◽  
Cadaveric Study ◽  
Ankle Arthroscopy ◽  
Anterior Tibial Artery ◽  
Tibial Artery ◽  
Anterior Tibial ◽  
Branching Point

Background. This study characterized the anterior medial malleolar artery (AMMA) branching from the anterior tibial artery (ATA) to identify problems in anterior ankle arthroscopy possibly contributing to injury to the AMMA. Methods. Barium was injected into 12 adult cadaveric feet via the external iliac artery and the origin and branching direction of the AMMA were identified on computed tomography. Results. The AMMA originated from the level of the ankle joint and below and above the ankle joint line (AJL) in 4 (33.3%), 6 (50.0%), and 1 (8.3%) specimen, respectively. Mean distance from the AJL to the branching point of the AMMA on the sagittal plane was 2.5 mm distal to the AJL. Mean angle between the distal longitudinal axis of the ATA and AMMA was 83.2°. Conclusions. This study established the origin and branching of the AMMA from the ATA. The AMMA should be examined carefully during ankle arthroscopy. Levels of Evidence: Level IV: Cadaveric study

Testing of primary stability of the Activ® L intervertebral disc prosthesis in cadaver bone and comparison of the two different anchoring concepts – keel and spike anchoring

2020 ◽  
Author(s):  
Christoph von Schulze Pellengahr ◽  
Wolfram Teske ◽  
Saurabh Kapoor ◽  
Alexander Klein ◽  
Bernd Wegener ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Statistical Significance ◽  
Primary Stability ◽  
Longitudinal Axis ◽  
Disc Prosthesis ◽  
Mean Values ◽  
Intervertebral Disc Prosthesis ◽  
Flexion Extension ◽  
Micro Motion

Abstract Background: High primary stability is the fundamental prerequisite for safe osseointegration of cementless intervertebral disc prosthesis. The aim of our study was to determine the primary stability of intervertebral disc prosthesis with two different anchoring concepts – keel and spike anchoring. Methods: 10 human cadaveric lumbar spine specimens with an ActivL intervertebral disc prosthesis (5 x keel anchoring, 5 x spike anchoring) were tested on a spine simulator. Under axial load, moments of flexion, extension, left and right bending and axial rotation were applied on the lumbar spine specimens through a defined three-dimensional movement program as per ISO 2631 and ISO/CD 18192-1.3 standards. Micro-motion of the implant was measured in every axis for both anchor types and compared using statistical test for significance after calculating 95% confidence intervals. Results: In the transverse axis, the keel anchoring concept showed lower mean values of micro-motion , which was statistically significant (p<0.05) compared to spike anchoring concept. In the sagittal axis, the results were again in favour of the keel anchoring, but did not reach statistical significance (p>0.05). The highest micro-motion values were observed in the longitudinal axis. Both concepts showed values around the threshold of primary stability (150 μm) with the spike concept showing lower mean values, but without a statistically significant difference.Conclusions: Both types of anchors met the criteria of primary stability. The keel anchoring shows a slight advantage compared to anchoring with spikes. Direct postoperative active mobilization doesn’t seem to compromise the primary stability of the prosthesis.

Individuals with low back pain improve in standing tolerance and sagittal plane muscle activation following exercise intervention

2019 ◽  
Vol 32 (6) ◽  
pp. 885-895 ◽  
Author(s):  
Evan Ingerson ◽  
Christopher Renfrow ◽  
Erin Aragon ◽  
Nathan Ferger ◽  
Britta Olson ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Muscle Activation ◽  
Exercise Intervention ◽  
Sagittal Plane ◽  
Low Back

Organizing principles for voluntary movement: extending single-joint rules

1995 ◽  
Vol 74 (4) ◽  
pp. 1374-1381 ◽  
Author(s):  
G. L. Almeida ◽  
D. A. Hong ◽  
D. Corcos ◽  
G. L. Gottlieb
Keyword(s):  
Muscle Activation ◽  
Sagittal Plane ◽  
Movement Control ◽  
General Rule ◽  
Dynamic Interactions ◽  
Multijoint Movement ◽  
Muscle Activation Patterns ◽  
Antagonist Muscles ◽  
The Subject ◽  
Emg Patterns

1. Four subjects performed fast flexions of the elbow or shoulder over three different distances. Elbow flexions were performed both in a horizontal, single-degree-of-freedom manipulandum and in a sagittal plane with the limb unconstrained. Shoulder flexions were only performed in the sagittal plane by the unconstrained limb. We simultaneously recorded kinematic and electromyographic (EMG) patterns at the “focal” joint, that which the subject intentionally flexed, and at the other, “nonfocal” joint that the subject had been instructed to not flex. 2. Comparisons of the elbow EMG patterns across tasks show that agonist and antagonist muscles were similar in pattern but not size, reflecting the net muscle torque patterns. Comparisons at the shoulder also revealed similar EMG patterns across tasks that reflected net muscle torques. 3. Comparisons of EMG patterns across joints show that elbow and shoulder flexors behaved similarly. This was not true of the extensors. The triceps EMG burst was delayed for longer distances but the posterior deltoid had an early, distance-invariant onset. 4. Similarities in EMG reflect torque demands required at the focal joint to produce flexion and at the nonfocal joint to reduce extension induced by dynamic interactions with the focal, flexing joint. These similarities appear despite very different kinematic intentions and outcomes. This argues against a strong role for length-sensitive reflexes in their generation. 5. These results support the hypothesis that movements are controlled by muscle activation patterns that are planned for the expected torque requirements of the task. This general rule is true whether we are performing single-joint or multiple-joint movements, with or without external constraints. The similarities between single-joint and multijoint movement control may be a consequence of ontogenetic development of multijoint movement strategies that prove useful and are therefore also expressed under the constrained conditions of specialized tasks such as those performed in single-joint manipulanda.

Correlation Between Quadriceps, Hamstring, Tibialis Anterior, and Gastrocnemius Muscle Activation, With Knee Flexion Angle In Basketball Athlete While Performing Double-Leg Landing Task

2020 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
Ditaruni Asrina Utami
Keyword(s):  
Knee Flexion ◽  
Tibialis Anterior ◽  
Muscle Activation ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Acl Injury ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Cross Sectional ◽  
Activation Ratio

ABSTRACTBackground: Anterior cruciate ligament (ACL) injury cause great disability for athlete. Recent focus of ACL injury management is on prevention by identifying the risk factors. Most of basketball injury mechanism is non-contact, related to landing process with small knee flexion angle. Muscle activation and its ratio, which control movement pattern in sagittal plane, are said to play a role in dynamic movement such as landing.Aims: The purpose of this study is to analyze the correlation between muscles activation and their activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with knee flexion angle of basketball athlete while performing double-leg landing task.Material and methods: This study was an observational analytic, cross sectional study. Study subjects was basketball athletes age 16 – 25 years in Surabaya. Measurements of knee flexion angle done with digital measurements of reflective marker, and muscle activation was measured with sEMG while performing double-leg landing task.Result: There was no significant correlation between maximum knee flexion angle and muscle activation of quadriceps (p=0,562), hamstring (p=0,918), tibialis anterior (p=0,394) and gastrocnemius (p=0,419). There was also no significant correlation between maximum knee flexion angle and the muscle activation ratio of quadriceps-hamstring (p=0,347), quadriceps-tibialis (p=0,139), quadriceps-gastrocnemius (p=0,626), hamstring-tibialis anterior (p=0,365), hamstring-gastrocnemius (p=0,867), and tibialis anterior-gastrocnemius (p=0,109).Conclusions: There was no correlation between muscle activation and muscle activation ratio of quadriceps, hamstring, tibialis anterior and gastrocnemius with maximum knee flexion angle in basketball athlete while performing double-leg landing task.

scholarly journals Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

2015 ◽  
Vol 50 (9) ◽  
pp. 905-913 ◽  
Author(s):  
Carolyn M. Meinerz ◽  
Philip Malloy ◽  
Christopher F. Geiser ◽  
Kristof Kipp
Keyword(s):  
Lower Extremity ◽  
Muscle Activation ◽  
National Collegiate Athletic Association ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Contact Angles ◽  
Ligament Injury ◽  
Initial Contact ◽  
Internal Joint ◽  
External Rotator

Context  Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. Objective  To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Design  Controlled laboratory study. Setting  University biomechanics laboratory. Participants  Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Intervention(s)  Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Main Outcome Measure(s)  Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Results  Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Conclusions  Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition.

The Borg Scale Validation for a Consumer Product - Automobile Polishes

1984 ◽  
Vol 28 (1) ◽  
pp. 98-101
Author(s):  
J. Kreifeldt ◽  
P. Hill ◽  
M. M. Clarke ◽  
J. Draper
Keyword(s):  
Heart Rate ◽  
Scale Validation ◽  
Bicycle Ergometer ◽  
Weight Lifting ◽  
Superior Performance ◽  
Work Effort ◽  
Borg Scale ◽  
Predictive Utility ◽  
Perceived Effort ◽  
Numerical Rating

The Borg scale which is purported to correlate subjectively perceived heart rate with objective physiological workload was tested for its predictive utility by subjects using 5 different car wax formulations. Subjects applied and removed the waxes from a high gloss painted panel. The amount of effort and time expended with each wax were determined using a force platform and timing device. Subjects also gave a Borg scale numerical rating as they used each wax. The reported high correlation between Borg scale ratings and exercises using a bicycle ergometer, weight lifting, etc. suggested that it might be a reliable predictor of workload effort or time in such common tasks as car waxing. Results indicate that the ability of the Borg values to predict either amount of time taken or effort expended was moderate (r =.58) on average, with a relatively high correlation between time and effort (r = .61). The rank orders of averages for Borg values and work effort, however, agreed well across the five waxes. Additionally, results clearly indicated superior performance (actual and perceived effort) of a newly formulated wax.

scholarly journals Similarity of Joint Kinematics and Muscle Demands Between Elliptical Training and Walking: Implications for Practice

2010 ◽  
Vol 90 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Judith M. Burnfield ◽  
Yu Shu ◽  
Thad Buster ◽  
Adam Taylor
Keyword(s):  
Decision Making ◽  
Muscle Activation ◽  
Clinical Decision Making ◽  
Sagittal Plane ◽  
Clinical Decision ◽  
Joint Kinematics ◽  
Vastus Lateralis Muscle ◽  
Evidence Based ◽  
Walking Ability ◽  
Repeated Measures Design

Background People with physical disabilities often face barriers to regaining walking ability and fitness after discharge from rehabilitation. Physical therapists are uniquely positioned to teach clients the knowledge and skills needed to exercise on functionally relevant equipment available in the community, such as elliptical trainers. However, therapeutic use is hindered by a lack of empirical information. Objective The purpose of this study was to examine joint kinematics and muscle activation recorded during walking and elliptical training to provide evidence-based data to guide clinical decision making. Design This was a prospective, controlled laboratory study using a repeated-measures design. Methods Twenty adults free from impairments that might hinder gait participated. After familiarization procedures, subjects walked and trained on 4 elliptical devices while kinematic, electromyographic (EMG), and stride characteristic data were recorded. Results Movement similarities between elliptical training and walking were supported by the documentation of relatively high coefficients of multiple correlation for the hip (.85–.89), thigh (.92–.94), knee (.87–.89) and, to a lesser extent, the ankle (.57–.71). Significantly greater flexion was documented at the trunk, pelvis, hip, and knee during elliptical training than during walking. One of the elliptical trainers most closely simulated sagittal-plane walking kinematics, as determined from an assessment of key variables. During elliptical training, gluteus maximus and vastus lateralis muscle activation were increased; medial hamstring, gastrocnemius, soleus, and tibialis anterior muscle activation were decreased; and gluteus medius and lateral hamstring muscle activation were relatively unchanged compared with muscle activation of those muscles in walking. On the basis of EMG findings, no elliptical trainer clearly emerged as the best for simulating gait. Limitations To date, only 4 elliptical trainers have been studied, and the contributions of the upper extremities to movement have not been quantified. Conclusions Although one of the elliptical trainers best simulated sagittal-plane walking kinematics, EMG analysis failed to identify one clearly superior device. This research provides evidence-based data to help guide clinical decision making related to the use of elliptical trainers across the health care continuum and into the community.

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