KINEMATIC ANALYSIS BY GENDER IN DIFFERENT JUMP TESTS BASED ON A SMARTPHONE INERTIAL SENSOR

ABSTRACT Introduction: Vertical jump tests can be used as estimators of muscular power, physical capacity, motor development and functional capacity. The ability to jump can be analyzed with different methods, including the use of inertial sensors. Objective: To describe and analyze kinematic characteristics using the inertial sensor integrated into the iPhone 4S® and jump contact mat variables in the squat jump (SJ) and countermovement jump (CMJ) tests, and to determine the interaction between kinetic and kinematic variables. Methods: A cross-sectional study was conducted with 27 healthy young adults. The primary outcome measures were linear acceleration, flight time, contact time, jump height and dynamometry of the knee extensors. Spearman's rho was used to investigate the correlation between variables. The Mann–Whitney U rank-sum test was used for the analysis of intergender variance. Results: The greatest difference between groups (gender) was in the dynamometry variables (p<0.001) and contact mat variables (p<0.001). Between the jump tests, the greatest difference between groups (gender) was in the CMJ test (p<0.001). Conclusion: The inertial sensor embedded in the smartphone demonstrated a correlation with the jump mat and the dynamometry. Finally, the higher kinetic and kinematic scores observed in the jumps performed by male participants than in those performed by female participants suggest that they can be used to better characterize their jumping profile. Level of Evidence IV; Diagnostic Studies - Investigating a Diagnostic Test.

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Head Impact Biomechanics in Youth Flag Football: A Prospective Cohort Study

The American Journal of Sports Medicine ◽

10.1177/03635465211026643 ◽

2021 ◽

pp. 036354652110266

Author(s):

Landon B. Lempke ◽

Rachel S. Johnson ◽

Rachel K. Le ◽

Melissa N. Anderson ◽

Julianne D. Schmidt ◽

...

Keyword(s):

Mixed Model ◽

Linear Acceleration ◽

Cross Sectional Study ◽

Head Impact ◽

Rotational Acceleration ◽

Event Type ◽

Level Of Evidence ◽

Cross Sectional ◽

Head Impact Biomechanics ◽

Impact Biomechanics

Background: Youth flag football participation has rapidly grown and is a potentially safer alternative to tackle football. However, limited research has quantitatively assessed youth flag football head impact biomechanics. Purpose: To describe head impact biomechanics outcomes in youth flag football and explore factors associated with head impact magnitudes. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We monitored 52 player-seasons among 48 male flag football players (mean ± SD; age, 9.4 ± 1.1 years; height, 138.6 ± 9.5 cm; mass, 34.7 ± 9.2 kg) across 3 seasons using head impact sensors during practices and games. Sensors recorded head impact frequencies, peak linear ( g) and rotational (rad/s2) acceleration, and estimated impact location. Impact rates (IRs) were calculated as 1 impact per 10 player-exposures; IR ratios (IRRs) were used to compare season, event type, and age group IRs; and 95% CIs were calculated for IRs and IRRs. Weekly and seasonal cumulative head impact frequencies and magnitudes were calculated. Mixed-model regression models examined the association between player characteristics, event type, and seasons and peak linear and rotational accelerations. Results: A total of 429 head impacts from 604 exposures occurred across the study period (IR, 7.10; 95% CI, 4.81-10.50). Weekly and seasonal cumulative median head impact frequencies were 1.00 (range, 0-2.63) and 7.50 (range, 0-21.00), respectively. The most frequent estimated head impact locations were the skull base (n = 96; 22.4%), top of the head (n = 74; 17.2%), and back of the head (n = 66; 15.4%). The combined event type IRs differed among the 3 seasons (IRR range, 1.45-2.68). Games produced greater IRs (IRR, 1.24; 95% CI, 1.01-1.53) and peak linear acceleration (mean difference, 5.69 g; P = .008) than did practices. Older players demonstrated greater combined event–type IRs (IRR, 1.46; 95% CI, 1.12-1.90) and increased head impact magnitudes than did younger players, with every 1-year age increase associated with a 3.78 g and 602.81-rad/s2 increase in peak linear and rotational acceleration magnitude, respectively ( P≤ .005). Conclusion: Head IRs and magnitudes varied across seasons, thus highlighting multiple season and cohort data are valuable when providing estimates. Head IRs were relatively low across seasons, while linear and rotational acceleration magnitudes were relatively high.

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Kinematic Mobile Drop Jump Analysis at Different Heights Based on a Smartphone Inertial Sensor

Journal of Human Kinetics ◽

10.2478/hukin-2019-0131 ◽

2020 ◽

Vol 73 (1) ◽

pp. 57-65

Author(s):

Alvaro Mateos-Angulo ◽

Alejandro Galán-Mercant ◽

Antonio Ignacio Cuesta-Vargas

Keyword(s):

Young Adults ◽

Inertial Sensor ◽

Linear Acceleration ◽

Cross Sectional Study ◽

Jump Height ◽

Drop Jump ◽

Maximum Acceleration ◽

Cross Sectional ◽

Jump Test ◽

Relevant Variables

AbstractThe purpose of this study was to describe the acceleration variables in a plyometric jump test using the inertial sensor built into an iPhone 4S® smartphone, and the jumping variables from a contact mat. A cross-sectional study was conducted involving 16 healthy young adults. Linear acceleration, flight time, contact time and jump height were measured in a drop jump test from 60 cm and from 30 cm. Greater acceleration values were found in the drop jump test from 60 cm; the same was observed for the values from the contact mat. Multiple regression analysis was performed for each drop jump test: jump height was used as the dependent variable, and the most relevant variables were used as predictor variables (weight and maximum angular velocity in the Y axis for analysis of the drop jump from 60 cm, and weight and maximum acceleration in the Z axis for the drop jump from 30 cm). We found a significant regression model for the drop jump test from 60 cm (R2 = 0.515, p “ 0.001) and for the test from 30 cm (R2 = 0.460, p “ 0.01). According to the results obtained in this study, the built-in iPhone 4S® inertial sensor is able to measure acceleration for healthy young adults performing a vertical drop jump test. The acceleration kinematic variables are higher in the drop jump test from 60 cm than from 30 cm.

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Reliability of a Smartphone Compared With an Inertial Sensor to Measure Shoulder Mobility: Cross-Sectional Study (Preprint)

10.2196/preprints.13640 ◽

2019 ◽

Author(s):

Cristina Roldán-Jiménez ◽

Jaime Martin-Martin ◽

Antonio I Cuesta-Vargas

Keyword(s):

Inertial Sensors ◽

Inertial Sensor ◽

Cross Sectional Study ◽

Functional Tests ◽

Cross Sectional ◽

Cronbach Alpha ◽

Interclass Correlation ◽

Shoulder Flexion ◽

The Cost ◽

Measuring Tool

BACKGROUND The shoulder is one of the joints with the greatest mobility within the human body and its evaluation is complex. An assessment can be conducted using questionnaires or functional tests, and goniometry can complement the information obtained in this assessment. However, there are now validated devices that can provide more information on the realization of movement, such as inertial sensors. The cost of these devices is usually high and they are not available to all clinicians, but there are also inertial sensors that are implemented in mobile phones which are cheaper and widely available. Results from the inertial sensors integrated into mobile devices can have the same reliability as those from dedicated sensors. OBJECTIVE This study aimed to validate the use of the Nexus 4 smartphone as a measuring tool for the mobility of the humerus during shoulder movement compared with a dedicated InertiaCube3 (Intersense) sensor. METHODS A total of 43 subjects, 27 affected by shoulder pathologies and 16 asymptomatic, participated in the study. Shoulder flexion, abduction, and scaption were measured using an InertiaCube3 and a Nexus 4 smartphone, which were attached to the participants to record the results simultaneously. The interclass correlation coefficient (ICC) was calculated based on the 3 movements performed. RESULTS The smartphone reliably recorded the velocity values and simultaneously recorded them alongside the inertial sensor. The ICCs of the 3 gestures and for each of the axes of movement were analyzed with a 95% CI. In the abduction movement, the devices demonstrated excellent interclass reliability for the abduction humeral movement axis (Cronbach alpha=.98). The axis of abduction of the humeral showed excellent reliability for the movements of flexion (Cronbach alpha=.93) and scaption (Cronbach alpha=.98). CONCLUSIONS Compared with the InertiaCube3, the Nexus 4 smartphone is a reliable and valid tool for recording the velocity produced in the shoulder.

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Reliability of a Smartphone Compared With an Inertial Sensor to Measure Shoulder Mobility: Cross-Sectional Study

JMIR mhealth and uhealth ◽

10.2196/13640 ◽

2019 ◽

Vol 7 (9) ◽

pp. e13640

Author(s):

Cristina Roldán-Jiménez ◽

Jaime Martin-Martin ◽

Antonio I Cuesta-Vargas

Keyword(s):

Inertial Sensors ◽

Inertial Sensor ◽

Cross Sectional Study ◽

Functional Tests ◽

Cross Sectional ◽

Cronbach Alpha ◽

Interclass Correlation ◽

Shoulder Flexion ◽

The Cost ◽

Measuring Tool

Background The shoulder is one of the joints with the greatest mobility within the human body and its evaluation is complex. An assessment can be conducted using questionnaires or functional tests, and goniometry can complement the information obtained in this assessment. However, there are now validated devices that can provide more information on the realization of movement, such as inertial sensors. The cost of these devices is usually high and they are not available to all clinicians, but there are also inertial sensors that are implemented in mobile phones which are cheaper and widely available. Results from the inertial sensors integrated into mobile devices can have the same reliability as those from dedicated sensors. Objective This study aimed to validate the use of the Nexus 4 smartphone as a measuring tool for the mobility of the humerus during shoulder movement compared with a dedicated InertiaCube3 (Intersense) sensor. Methods A total of 43 subjects, 27 affected by shoulder pathologies and 16 asymptomatic, participated in the study. Shoulder flexion, abduction, and scaption were measured using an InertiaCube3 and a Nexus 4 smartphone, which were attached to the participants to record the results simultaneously. The interclass correlation coefficient (ICC) was calculated based on the 3 movements performed. Results The smartphone reliably recorded the velocity values and simultaneously recorded them alongside the inertial sensor. The ICCs of the 3 gestures and for each of the axes of movement were analyzed with a 95% CI. In the abduction movement, the devices demonstrated excellent interclass reliability for the abduction humeral movement axis (Cronbach alpha=.98). The axis of abduction of the humeral showed excellent reliability for the movements of flexion (Cronbach alpha=.93) and scaption (Cronbach alpha=.98). Conclusions Compared with the InertiaCube3, the Nexus 4 smartphone is a reliable and valid tool for recording the velocity produced in the shoulder.

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Vertical Jump Height Estimation Algorithm Based on Takeoff and Landing Identification Via Foot-Worn Inertial Sensing

Journal of Biomechanical Engineering ◽

10.1115/1.4038740 ◽

2018 ◽

Vol 140 (3) ◽

Cited By ~ 1

Author(s):

Jianren Wang ◽

Junkai Xu ◽

Peter B. Shull

Keyword(s):

Motion Capture ◽

Motor Development ◽

Inertial Sensors ◽

Inertial Sensor ◽

Vertical Jump ◽

Jump Height ◽

Inertial Sensing ◽

Estimation Errors ◽

Height Estimation ◽

Vertical Jump Height

Vertical jump height is widely used for assessing motor development, functional ability, and motor capacity. Traditional methods for estimating vertical jump height rely on force plates or optical marker-based motion capture systems limiting assessment to people with access to specialized laboratories. Current wearable designs need to be attached to the skin or strapped to an appendage which can potentially be uncomfortable and inconvenient to use. This paper presents a novel algorithm for estimating vertical jump height based on foot-worn inertial sensors. Twenty healthy subjects performed countermovement jumping trials and maximum jump height was determined via inertial sensors located above the toe and under the heel and was compared with the gold standard maximum jump height estimation via optical marker-based motion capture. Average vertical jump height estimation errors from inertial sensing at the toe and heel were −2.2±2.1 cm and −0.4±3.8 cm, respectively. Vertical jump height estimation with the presented algorithm via inertial sensing showed excellent reliability at the toe (ICC(2,1)=0.98) and heel (ICC(2,1)=0.97). There was no significant bias in the inertial sensing at the toe, but proportional bias (b=1.22) and fixed bias (a=−10.23cm) were detected in inertial sensing at the heel. These results indicate that the presented algorithm could be applied to foot-worn inertial sensors to estimate maximum jump height enabling assessment outside of traditional laboratory settings, and to avoid bias errors, the toe may be a more suitable location for inertial sensor placement than the heel.

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Prevalence of Morphological Variations Associated With Femoroacetabular Impingement According to Age and Sex: A Study of 1878 Asymptomatic Hips in Nonprofessional Athletes

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120977892 ◽

2021 ◽

Vol 9 (2) ◽

pp. 232596712097789

Author(s):

Rodolfo Morales-Avalos ◽

Adriana Tapia-Náñez ◽

Mario Simental-Mendía ◽

Guillermo Elizondo-Riojas ◽

Michelle Morcos-Sandino ◽

...

Keyword(s):

Femoroacetabular Impingement ◽

Alpha Angle ◽

Cross Sectional Study ◽

Level Of Evidence ◽

Crossover Sign ◽

Cross Sectional ◽

Radiographic Findings ◽

Morphological Variations ◽

Pelvic Radiographs ◽

Center Edge

Background: Radiographic findings related to the cam and pincer variants of femoroacetabular impingement (FAI) include measurements of the alpha angle and lateral center-edge angle (LCEA). The function of these radiographic findings has been put into question because of high heterogeneity in reported studies. Purpose: The aim of this study was 3-fold: (1) to determine the prevalence of cam and pincer variants according to sex and age on anteroposterior (AP) pelvic radiographs from an asymptomatic nonathletic population, (2) to identify the most common radiographic signs of cam- and pincer-type variants, and (3) to determine if there are variations in the prevalence of these radiographic signs according to sex and age. Study Design: Cross-sectional study; Level of evidence, 3. Methods: There were 3 independent observers who retrospectively analyzed the 939 AP pelvic radiographs (1878 hips) of patients aged 18 to 50 years who did not have hip symptoms and who were not professional athletes. The prevalence of the cam and pincer variants according to the alpha angle and LCEA, respectively, and the presence of other radiographic signs commonly associated with these variables were determined in the overall population and by subgroup according to sex and age group (18-30, 31-40, and 41-50 years). Descriptive and inferential statistics were used to analyze the study sample. Results: The mean age of the included population was 31.0 ± 9.2 years, and 68.2% were male. The prevalence of the cam-type variant was 29.7% (558/1878), and that of the pincer-type variant was 24.3% (456/1878). The radiographic signs that were most associated with the cam and pincer variants were a pistol-grip deformity and the crossover sign, respectively. Significant differences ( P < .001) in the prevalence of these variants were identified between men and women in both variants. No differences were observed in the alpha angle or LCEA according to sex or age. Conclusion: Radiographic findings suggestive of FAI had significant variations with respect to sex and age in this study sample. This study provides information to determine the prevalence of these anatomic variants in the general population.

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Effect of the COVID-19 pandemic on the ability of level 1 trauma centers to meet American College of Surgeons research requirements

Trauma Surgery & Acute Care Open ◽

10.1136/tsaco-2021-000692 ◽

2021 ◽

Vol 6 (1) ◽

pp. e000692

Author(s):

Robert M Madayag ◽

Erica Sercy ◽

Gina M Berg ◽

Kaysie L Banton ◽

Matthew Carrick ◽

...

Keyword(s):

Cross Sectional Study ◽

Trauma Centers ◽

Level Of Evidence ◽

Cross Sectional ◽

American College Of Surgeons ◽

The Usa ◽

Virus Exposure ◽

Level 1 ◽

Verification Process ◽

Question Survey

IntroductionThe COVID-19 pandemic has had major effects on hospitals’ ability to perform scientific research while providing patient care and minimizing virus exposure and spread. Many non-COVID-19 research has been halted, and funding has been diverted to COVID-19 research and away from other areas.MethodsA 28-question survey was administered to all level 1 trauma centers in the USA that included questions about how the pandemic affected the trauma centers’ ability to fulfill the volume and research requirements of level 1 verification by the American College of Surgeons (ACS).ResultsThe survey had a 29% response rate (40/137 successful invitations). Over half of respondents (52%) reported reduced trauma admissions during the pandemic, and 7% reported that their admissions dropped below the volume required for level 1 verification. Many centers diverted resources from research during the pandemic (44%), halted ongoing consenting studies (33%), and had difficulty fulfilling research requirements because of competing clinical priorities (40%).DiscussionResults of this study show a need for flexibility in the ACS verification process during the COVID-19 pandemic, potentially including reduction of the required admissions and/or research publication volumes.Level of evidenceLevel IV, cross-sectional study.

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School-Time Movement Behaviors and Fundamental Movement Skills in Preschoolers: An Isotemporal Reallocation Analysis

Perceptual and Motor Skills ◽

10.1177/00315125211013196 ◽

2021 ◽

pp. 003151252110131

Author(s):

Clarice Maria de Lucena Martins ◽

Cain Craig Truman Clark ◽

Rafael Miranda Tassitano ◽

Anastácio Neco de Souza Filho ◽

Anelise Reis Gaya ◽

...

Keyword(s):

Low Income ◽

Motor Development ◽

Compositional Analysis ◽

Cross Sectional Study ◽

Fine Motor ◽

Cross Sectional ◽

Movement Skills ◽

School Time ◽

Fundamental Movement Skills ◽

Time Movement

Little is known of how reallocations of time spent in different movement behaviors during preschool might relate to preschoolers’ fundamental movement skills (FMS), a key predictor of later physical activity (PA). Thus, the aim of this study was to examine (a) whether preschoolers’ school-time movement was associated with their FMS and (b) the effects on FMS of reallocating time between PA and sedentary behavior (SB). This was a cross-sectional study, using intervention data with Brazilian low-income preschoolers. We observed Brazilian preschoolers of both sexes ( Mage = 4.5, SD = 0.8 years-old; 101boys) over 10 hours of school-time and objectively assessed their PA and SB with Actigraph wGT3X and their FMS with the Test of Gross Motor Development – Second Edition. We explored the associations between school-time movement behaviors and FMS and between reallocated school-time movement behaviors and FES using compositional analysis in R (version 1.40-1), robCompositions (version 0.92-7), and lmtest (version 0.9-35) packages. This isotemporal reallocation showed that, for manipulative skills, reallocating time (5, 10, and 15 minutes, respectively) from light PA to SB was associated with increasing skill (0.14, 0.28, and 0.42 FMS units), raising questions as to whether fine motor activity occurred during SB. Thus, school-time movement significantly predicted FMS, with a modest increase in SB, at the expense of light PA eliciting improved manipulative skills.

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Factors Associated With Knee Pain and Heel Pain in Youth Soccer Players Aged 8 to 12 Years

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119883370 ◽

2019 ◽

Vol 7 (11) ◽

pp. 232596711988337 ◽

Cited By ~ 1

Author(s):

Toshiyuki Iwame ◽

Tetsuya Matsuura ◽

Naoto Suzue ◽

Joji Iwase ◽

Hirokazu Uemura ◽

...

Keyword(s):

Knee Pain ◽

Cross Sectional Study ◽

Heel Pain ◽

Older Age ◽

Soccer Players ◽

Clinical Factors ◽

Level Of Evidence ◽

Cross Sectional ◽

Youth Soccer ◽

Study Participants

Background: Soccer is played by many children younger than 12 years. Despite its health benefits, soccer has also been linked to a high number of sport-related injuries. Purpose: To investigate the relationship between clinical factors and knee or heel pain in youth soccer players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Study participants included 602 soccer players aged 8 to 12 years who were asked whether they had experienced episodes of knee or heel pain. Data were collected on age, body mass index, years of playing soccer, playing position, and training hours per week. Associations of clinical factors with the prevalence of knee or heel pain were examined by univariate and multivariate logistic regression analyses. Results: Episodes of knee and heel pain were reported by 29.4% and 31.1% of players, respectively. Multivariate analyses revealed that older age and more years of playing soccer were significantly and positively associated with the prevalence of knee pain ( P = .037 and P = .015 for trend, respectively) but did not identify any significant associations for heel pain. Conclusion: In this study of youth soccer players, knee pain was associated with older age and more years of play, but heel pain was not significantly associated with any factor.

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Acetabular Chondral Lesions in Hip Arthroscopy: Relationships Between Grade, Topography, and Demographics

The American Journal of Sports Medicine ◽

10.1177/0363546517708192 ◽

2017 ◽

Vol 45 (11) ◽

pp. 2501-2506 ◽

Cited By ~ 18

Author(s):

Carlos Suarez-Ahedo ◽

Chengcheng Gui ◽

Stephanie M. Rabe ◽

Sivashankar Chandrasekaran ◽

Parth Lodhia ◽

...

Keyword(s):

Traumatic Injury ◽

Demographic Factors ◽

Patient Characteristics ◽

Cross Sectional Study ◽

Chondral Lesion ◽

Level Of Evidence ◽

Cross Sectional ◽

Chondral Lesions ◽

Chondral Damage ◽

Male Sex

Background: Hip pain remains a challenge given the multiple factors that can cause damage to the articular cartilage, such as traumatic injury, metabolic damage, and morphologic variations such as femoroacetabular impingement (FAI) and that can contribute to progression of osteoarthritis. However, a direct relationship between patient characteristics, the extent of acetabular chondral damage, and topologic characteristics of chondral lesions has not been established. Purpose: To compare the grade of acetabular chondral damage, measured in terms of acetabular labrum articular disruption (ALAD) classification, to the size and position of the chondral lesions, matching patients’ demographic factors such as age and body mass index (BMI). Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study included all hip arthroscopies performed by the corresponding author from August 7, 2008, to November 19, 2014, in which acetabular chondral lesions were intraoperatively identified and measured in terms of ALAD grade, clockface location, and size. Bivariate analyses and multiple logistic regression were used to identify the demographic factors, characteristics of the acetabular chondral lesion, and other anatomic characteristics that were related to the ALAD grade of the acetabular chondral lesion. Results: Acetabular chondral lesions were measured in 1502 patients during the study period. Multivariate analysis showed that higher ALAD grade of acetabular chondral damage was significantly related to male sex, more advanced age, the area of the acetabular chondral lesion, anterior extension of the acetabular chondral lesion within the anterosuperior quadrant, labral detachment from the acetabular cartilage, and posterior extension of the labral tear. Conclusion: Higher grades of acetabular chondral damage were related to male sex, increased age, height, weight, BMI, and the size of the lesion. Chondral lesions were generally found in the anterosuperior region of the acetabulum, consistent with labral lesions and the weightbearing area of the acetabulum.

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