A Comparison of Age Level on Baseball Hitting Kinematics

2009 ◽  
Vol 25 (3) ◽  
pp. 210-218 ◽  
Author(s):  
Rafael F. Escamilla ◽  
Glenn S. Fleisig ◽  
Coop DeRenne ◽  
Marcus K. Taylor ◽  
Claude T. Moorman ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Range Of Motion ◽  
High Speed ◽  
Knee Extension ◽  
Left Knee ◽  
Baseball Players ◽  
Left Elbow ◽  
Ball Contact ◽  
Analysis System ◽  
S Peak

We propose that learning proper hitting kinematics should be encouraged at a young age during youth baseball because this may help reinforce proper hitting kinematics as a player progresses to higher levels of baseball in their adult years. To enhance our understanding between youth and adult baseball hitting, kinematic and temporal analyses of baseball hitting were evaluated with a high-speed motion analysis system between 12 skilled youth and 12 skilled adult baseball players. There were only a small number of temporal differences between youth and adult hitters, with adult hitters taking significantly greater time than youth hitters during the stride phase and during the swing. Compared with youth hitters, adult hitters a) had significantly greater (p < .01) lead knee flexion when the hands started to move forward; b) flexed the lead knee over a greater range of motion during the transition phase (31° versus 13°); c) extended the lead knee over a greater range of motion during the bat acceleration phase (59° versus 32°); d) maintained a more open pelvis position at lead foot off ground; and e) maintained a more open upper torso position when the hands started to move forward and a more closed upper torso position at bat-ball contact. Moreover, adult hitters had greater peak upper torso angular velocity (857°/s versus 717°/s), peak left elbow extension angular velocity (752°/s versus 598°/s), peak left knee extension angular velocity (386°/s versus 303°/s), and bat linear velocity at bat-ball contact (30 m/s versus 25 m/s). The numerous differences in kinematic and temporal parameters between youth and adult hitters suggest that hitting mechanics are different between these two groups.

Relationship Between Weightbearing Ankle Dorsiflexion Passive Range of Motion and Ankle Kinematics During Gait

2017 ◽  
Vol 107 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Min-Hyeok Kang ◽  
Jae-Seop Oh
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Knee Extension ◽  
Ankle Dorsiflexion ◽  
Physically Active ◽  
Ankle Kinematics ◽  
The Difference ◽  
Analysis System ◽  
The Relationship ◽  
Paired T Test

Background: Measurement of weightbearing ankle dorsiflexion (DF) passive range of motion (PROM) has been suggested as a way to estimate ankle kinematics during gait; however, no previous study has demonstrated the relationship between ankle DF during gait and ankle DF PROM with knee extension. We examine the relationship between maximum ankle DF during gait and nonweightbearing and weightbearing ankle DF PROM with knee extension. Methods: Forty physically active individuals (mean ± SD age, 21.63 ± 1.73 years) participated in this study. Ankle DF PROM with knee extension was measured in the nonweightbearing and weightbearing conditions; maximum ankle DF during gait was assessed using a three-dimensional motion analysis system. The relationship between each variable was calculated using the Pearson product moment correlation coefficient, and the difference in ankle DF PROM between the nonweightbearing and weightbearing conditions was analyzed using a paired t test. Results: The weightbearing measurement (r = 0.521; P &lt; .001) for ankle DF PROM showed a greater correlation with maximum ankle DF during gait than did the nonweightbearing measurement (r = 0.245; P = .029). Ankle DF PROM was significantly greater in the weightbearing than in the nonweightbearing condition (P &lt; .001) despite a significant correlation between the two measurements (r = 0.402; P &lt; .001). Conclusions: These findings indicate that nonweightbearing and weightbearing measurements of ankle DF PROM with knee extension should not be used interchangeably and that weightbearing ankle DF PROM with the knee extended is more appropriate for estimating ankle DF during gait.

Effects of Bat Grip on Baseball Hitting Kinematics

2009 ◽  
Vol 25 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Rafael F. Escamilla ◽  
Glenn S. Fleisig ◽  
Coop DeRenne ◽  
Marcus K. Taylor ◽  
Claude T. Moorman ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Range Of Motion ◽  
Elbow Flexion ◽  
Linear Velocity ◽  
Elbow Extension ◽  
Kinematic Parameters ◽  
Time Duration ◽  
Motion System ◽  
Ball Contact ◽  
Pelvis Rotation

A motion system collected 120-Hz data from 14 baseball adult hitters using normal and choke-up bat grips. Six swings were digitized for each hitter, and temporal and kinematic parameters were calculated. Compared with a normal grip, the choke-up grip resulted in 1) less time during stride phase and swing; 2) the upper torso more opened at lead foot contact; 3) the pelvis more closed and less bat linear velocity at bat-ball contact; 4) less range of motion of the upper torso and pelvis during swing; 5) greater elbow flexion at lead foot contact; and 6) greater peak right elbow extension angular velocity. The decreased time during the stride phase when using a choke-up grip implies that hitters quicken their stride when they choke up. Less swing time duration and less upper torso and pelvis rotation range of motion using the choke-up grip supports the belief of many coaches and players that using a choke-up grip results in a “quicker” swing. However, the belief that using a choke-up grip leads to a faster moving bat was not supported by the results of this study.

scholarly journals Static vs. Dynamic Acute Stretching Effect on Quadriceps Muscle Activity during Soccer Instep Kicking

2013 ◽  
Vol 39 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Mohammadtaghi Amiri-Khorasani ◽  
Eleftherios Kellis
Keyword(s):  
Angular Velocity ◽  
Muscle Activity ◽  
High Speed ◽  
Muscle Activation ◽  
Body Height ◽  
Rectus Femoris ◽  
Quadriceps Muscle ◽  
Knee Extension ◽  
Emg Activity ◽  
Dynamic Stretching

Abstract The purpose of this study was to compare the effects of static and dynamic stretching on quadriceps muscle activation during maximal soccer instep kicking. The kicking motion of twelve male college soccer players (body height: 174.66 ± 5.01 cm; body mass: 72.83 ± 4.83 kg; age: 18.83 ± 0.75 years) was captured using six synchronized high-speed infra-red cameras whilst electromyography (EMG) signals from vastus medialis (VM), lateralis (VL) and rectus femoris (RF) were recorded before and after static or dynamic stretching. Analysis of variance designs showed a higher increase in knee extension angular velocity (9.65% vs. -1.45%, p < 0.001), RF (37.5% vs. -8.33%, p < 0.001), VM (12% vs. - 12%, p < 0.018), and VL EMG activity (20% vs. -6.67%, p < 0.001) after dynamic stretching exercises. Based on these results, it could be suggested that dynamic stretching is probably more effective in increasing quadriceps muscle activity and knee extension angular velocity during the final swing phase of a maximal soccer instep kick than static stretching.

Hip internal and external rotation range of motion reliability in youth baseball players

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Garrett S. Bullock ◽  
Edward C. Beck ◽  
Gary S. Collins ◽  
Stephanie R. Filbay ◽  
Kristen F. Nicholson
Keyword(s):  
Range Of Motion ◽  
External Rotation ◽  
Baseball Players ◽  
Youth Baseball

scholarly journals Gender Differences in Kinematic Analysis of the Lower Limbs during the Chasse Step in Table Tennis Athletes

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 703
Author(s):  
Xiaoyi Yang ◽  
Yuqi He ◽  
Shirui Shao ◽  
Julien S. Baker ◽  
Bíró István ◽  
...  
Keyword(s):  
Female Athletes ◽  
External Rotation ◽  
Rotational Velocity ◽  
Knee Extension ◽  
Lower Limbs ◽  
Table Tennis ◽  
Male Athletes ◽  
Analysis System ◽  
Hip Flexion ◽  
Hip Internal Rotation

The chasse step is one of the most important footwork maneuvers used in table tennis. The purpose of this study was to investigate the lower limb kinematic differences of table tennis athletes of different genders when using the chasse step. The 3D VICON motion analysis system was used to capture related kinematics data. The main finding of this study was that the step times for male athletes (MA) were shorter in the backward phase (BP) and significantly longer in the forward phase (FP) than for female athletes (FA) during the chasse step. Compared with FA, knee external rotation for MA was larger during the BP. MA showed a smaller knee flexion range of motion (ROM) in the BP and larger knee extension ROM in the FP. Moreover, hip flexion and adduction for MA were significantly greater than for FA. In the FP, the internal rotational velocity of the hip joint was significantly greater. MA showed larger hip internal rotation ROM in the FP but smaller hip external rotation ROM in the BP. The differences between genders can help coaches personalize their training programs and improve the performance of both male and female table tennis athletes.

A comparative study of the acute effects of knee brace vs. kinesiotape on selected isokinetic strength variables of the knee muscles

2021 ◽  
pp. 1-6
Author(s):  
Ali Kerim Yilmaz ◽  
Mehmet Vural ◽  
Mustafa Özdal ◽  
Menderes Kabadayi
Keyword(s):  
Knee Injuries ◽  
Knee Extension ◽  
Acute Effects ◽  
Post Injury ◽  
Kinesio Tape ◽  
Knee Strength ◽  
Significant Difference ◽  
S Peak ◽  
Male Subjects ◽  
Methods Of Treatment

BACKGROUND: Different methods of treatment for preventing knee injuries, enhancing knee strength and minimising post-injury risks have been explored. Among these methods, Kinesio tape (KT) and knee braces (KB) are commonly used. OBJECTIVE : To investigate the acute effects of KT and KB on isokinetic knee strength parameters. METHODS: A total of 15 healthy sedentary male subjects voluntarily participated in the study. Concentric isokinetic knee extension (EX) and flexion (FLX) strength were measured at three sessions: 1. Baseline 2. with KT (’KT’) 3. with KB (’KB’). Tests were performed at 60, 180 and 240∘/s. Peak moment (PM), Hamstring/Quadriceps ratio (HQR), and joint angle at peak moment (JAPM) were measured. RESULTS: ‘KT’ and ‘KB’ were associated with increase in PMEX, PMFLX, HQR at 60 and 240∘/s (p< 0.05) and increased JAPMEX. No significant difference was observed at 180∘/s (p> 0.05). CONCLUSION: In healthy individuals, ‘I’ shape KT and KB positively affect EX and FLX strengths and HQR, especially at low angular velocity.

scholarly journals Cutaneous mucinosis of infancy: a rare case of joint involvement

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Cristina Morreale ◽  
Dario Bleidl ◽  
Angela Rita Sementa ◽  
Clara Malattia
Keyword(s):  
Rare Case ◽  
Steroid Injection ◽  
Left Knee ◽  
Joint Involvement ◽  
Normal Range ◽  
Reticular Dermis ◽  
Case Presentation ◽  
Left Elbow ◽  
Inflammatory Drugs ◽  
One Year

Abstract Background Primary cutaneous mucinosis are a heterogeneous group of diseases characterized by the deposition of glycosaminoglycans in the dermis and the follicles. These diseases are rare in children therefore their diagnosis and management are still challenging. Joint involvement has been reported in patients with secondary cutaneous mucinosis and, rarely, in primary mucinosis. We describe a case of Cutaneous Mucinosis of Infancy with joint involvement. Case presentation An healthy 5-year-old boy showed acute arthritis of the left knee and left elbow confirmed by ultrasound. Laboratory tests were within normal range. Symptoms disappeared after a course of nonsteroid anti-inflammatory drugs. One year later, the knee swelling reappeared; juvenile idiopathic arthritis was diagnosed and intra-articular steroid injection was performed. Due to persistence of arthritis of the knee he was admitted to our hospital. On physical examination variable skin-colored lesions were observed, which had been in existence for over 2 years. We performed a skin biopsy that showed an interstitial mucine deposition in the reticular dermis. Cutaneous Mucinosis of Infancy was diagnosed. Discussion and conclusions Cutaneous Mucinosis of Infancy is a persistent dermatosis with benign prognosis and no treatment is generally required. Our case report is particularly interesting because it is the first in which joint involvement has been reported in CMI, a disorder that has so far been described as limited to skin involvement. Further studies will be necessary in order to clarify the pathogenesis of joint involvement in primary mucinosis.

scholarly journals The Optimization of Alternating Current Electrospun PA 6 Solutions Using a Visual Analysis System

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2098
Author(s):  
Tomas Kalous ◽  
Pavel Holec ◽  
Jakub Erben ◽  
Martin Bilek ◽  
Ondrej Batka ◽  
...  
Keyword(s):  
High Voltage ◽  
High Speed ◽  
Visual Analysis ◽  
Polyamide 6 ◽  
Alternating Current ◽  
Sine Wave ◽  
Electrospinning Process ◽  
Camera System ◽  
Polymeric Solutions ◽  
Analysis System

The electrospinning process that produces fine nanofibrous materials have a major disadvantage in the area of productivity. However, alternating current (AC) electrospinning might help to solve the problem via the modification of high voltage signal. The aforementioned productivity aspect can be observed via a camera system that focuses on the jet creation area and that measures the average lifespan. The paper describes the optimization of polyamide 6 (PA 6) solutions and demonstrates the change in the behavior of the process following the addition of a minor dose of oxoacid. This addition served to convert the previously unspinnable (using AC) solution to a high-quality electrospinning solution. The visual analysis of the AC electrospinning of polymeric solutions using a high-speed camera and a programmable power source was chosen as the method for the evaluation of the quality of the process. The solutions were exposed to high voltage applying two types of AC signal, i.e., the sine wave and the step change. All the recordings presented in the paper contained two sets of data: firstly, camera recordings that showed the visual expression of electrospinning and, secondly, signal recordings that provided information on the data position in the signal function.

Patient Self-Assessed Passive Range of Motion of the Knee Cannot Replace Health Professional Measurements

2017 ◽  
Vol 30 (08) ◽  
pp. 829-834
Author(s):  
Frank Madsen ◽  
Anders Odgaard ◽  
Jens Borgbjerg
Keyword(s):  
Range Of Motion ◽  
Knee Extension ◽  
Flexion Contracture ◽  
Patient Assessment ◽  
Limits Of Agreement ◽  
Self Assessment ◽  
Knee Motion ◽  
Bland Altman Method ◽  
Flexion And Extension ◽  
Patient Self Assessment

AbstractThe purpose of this study was to investigate whether patients can accurately self-assess their knee passive range of motion (PROM). A picture-based questionnaire for patient self-assessment of knee PROM was developed and posted to patients. The self-assessed PROM from 58 patients was compared with surgeon-assessed PROM using a short-arm goniometer. Agreement between the measurement methods was calculated with the Bland-Altman method. We calculated the sensitivity and specificity of patient-assessed PROM in dichotomously detecting knee motion impairment in both flexion (≤ 100 degrees) and extension (≥ 10-degree flexion contracture). Surgeon- and patient-assessed knee PROM showed a mean difference (95% limits of agreement) of −2.1 degrees (−42.5 to 38.3 degrees) for flexion and −8.1 degrees (−28.8 to 12.7 degrees) for extension. The sensitivity of patient self-assessed PROM in identifying knee flexion and extension impairments was 86 and 100%, respectively, whereas its specificity was 84 and 43%, respectively. Although wide limits of agreement were observed between surgeon- and patient-assessed knee PROM, the picture-based questionnaire for patient assessment of knee ROM was found to be a valid tool for dichotomously detecting knee motion impairment in flexion (≤ 100 degrees). However, the specificity of the questionnaire for detection of knee extension impairments (≥ 10-degree flexion contracture) was low, which limits is practical utility for this purpose.

scholarly journals Acute Effects of Doorway Stretch on the Glenohumeral Rotational Range of Motion and Scapular Position in High-School Baseball Players

2021 ◽  
Author(s):  
Takashi Higuchi ◽  
Yuichi Nakao ◽  
Yasuaki Tanaka ◽  
Masashi Sadakiyo ◽  
Koki Hamada ◽  
...  
Keyword(s):  
High School ◽  
Range Of Motion ◽  
Acute Effects ◽  
Baseball Players
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