scholarly journals Relationships between Hip Flexibility and Pitching Biomechanics in Adolescent Baseball Pitchers

2021 ◽  
Author(s):  
Maxwell L. Albiero ◽  
Wesley Kokott ◽  
Cody Dziuk ◽  
Janelle A. Cross
Keyword(s):  
External Rotation ◽  
Pearson Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Kinematic Chain ◽  
Abduction Angle ◽  
Cross Sectional ◽  
Flexion Extension ◽  
Hip Abduction ◽  
Baseball Pitchers

Abstract Context: Inadequate hip active range of motion (AROM) may stifle the energy flow through the kinematic chain and decrease pitching performance while increasing the risk for pitcher injury. Objective: To examine the relationship of hip AROM and pitching biomechanics during a fastball pitch in adolescent baseball pitchers. Design: Cross-Sectional study. Setting: Biomechanics laboratory. Participants: A voluntary sample of 21 adolescent baseball pitchers (16.1 ± 0.8 yrs.; 183.9 ± 5.2 cm; 77.9 ± 8.3 kg). Main Outcome Measure (s): Bilateral hip internal rotation (IR), external rotation (ER), flexion, extension, and abduction AROM were measured. Three-dimensional biomechanics were assessed as participants threw from an indoor pitching mound to a strike zone net at regulation distance. Pearson correlation coefficients were used to determine correlations between hip AROM and biomechanical metrics. Results: Statistically significant negative correlations were found at foot contact between back hip ER AROM and back hip abduction angle (p=0.030, r=−0.474), back hip ER AROM and torso rotation angle (p=0.032, r=−0.468),and back hip abduction AROM and lead hip abduction angle (p=0.037, r=−0.458). Back hip extension AROM was positively correlated with increased stride length (p=0.043, r=0.446). Lead hip abduction AROM was also positively correlated with normalized elbow varus torque (p=0.034, r=0.464). Conclusions: There were several relationships between hip AROM and biomechanical variables during the pitching motion. The findings support the influence hip AROM can have on pitching biomechanics. Overall, greater movement at the hips allows for the kinematic chain to work at its maximal efficiency, increasing pitch velocity potential.

scholarly journals The patellofemoral morphology and the normal predicted value of tibial tuberosity-trochlear groove distance in the Chinese population

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhe Li ◽  
Guanzhi Liu ◽  
Run Tian ◽  
Ning Kong ◽  
Yue Li ◽  
...  
Keyword(s):  
Individual Differences ◽  
Chinese Population ◽  
Pearson Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Tibial Tuberosity ◽  
Trochlear Groove ◽  
Lasso Regression ◽  
Cross Sectional ◽  
Anterior Posterior

Abstract Background Our objective was to obtain normal patellofemoral measurements to analyse sex and individual differences. In addition, the absolute values and indices of tibial tuberosity-trochlear groove (TT-TG) distances are still controversial in clinical application. A better method to enable precise prediction is still needed. Methods Seventy-eight knees of 78 participants without knee pathologies were included in this cross-sectional study. A CT scan was conducted for all participants and three-dimensional knee models were constructed using Mimics and SolidWorks software. We measured and analysed 19 parameters including the TT-TG distance and dimensions and shapes of the patella, femur, tibia, and trochlea. LASSO regression was used to predict the normal TT-TG distances. Results The dimensional parameters, TT-TG distance, and femoral aspect ratio of the men were significantly larger than those of women (all p values < 0.05). However, after controlling for the bias from age, height, and weight, there were no significant differences in TT-TG distances and anterior-posterior dimensions between the sexes (all p values > 0.05). The Pearson correlation coefficients between the anterior femoral offset and other indexes were consistently below 0.3, indicating no relationship or a weak relationship. Similar results were observed for the sulcus angle and the Wiberg index. Using LASSO regression, we obtained four parameters to predict the TT-TG distance (R2 = 0.5612, p < 0.01) to achieve the optimal accuracy and convenience. Conclusions Normative data of patellofemoral morphology were provided for the Chinese population. The anterior-posterior dimensions of the women were thicker than those of men for the same medial-lateral dimensions. More attention should be paid to not only sex differences but also individual differences, especially the anterior condyle and trochlea. In addition, this study provided a new method to predict TT-TG distances accurately.

scholarly journals Three-dimensional motion analysis of ten common Asian sitting positions in daily living and factors affect range of hip motions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Phob Ganokroj ◽  
Jirayu Chaowalitwong ◽  
Pichitpol Kerdsomnuek ◽  
Narumol Sudjai ◽  
Pisit Lertwanich ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Motion Analysis ◽  
External Rotation ◽  
Three Dimensional ◽  
Cross Sectional Study ◽  
Flexion Angle ◽  
Abduction Angle ◽  
Female Group ◽  
Cross Sectional ◽  
Kinematic Data

Abstract Background Sitting involves many activities of daily life and requires most motion in the hip joint. Asians have more hip flexion and external rotation motions than Westerners owing to cultural and lifestyle differences. Being aware of the normal range of hip motion is essential in clinical practice. Limited research has focused on the hip motions of common sitting positions. The objective was to determine the hip motions of 10 common sitting positions, and to determine whether gender or being overweight affects the range of hip motions. Methods An experimental cross-sectional study was conducted to determine hip motions by using a standard, three-dimensional, motion-analysis system. Healthy subjects performed 10 sitting positions during 3 trials. All hip-kinematic data were measured on the dominant leg of each participant, except for the right- and left-monk positions (both hips were analyzed). Density plots were constructed and statistical analyses were performed to detect the differences between groups (male and female; non-overweight and overweight). Results The 48 participants comprised 24 males and 24 females. Most were right-leg dominant (45 participants, 93.8%). Of the 22 participants in the overweight group (body mass index ≥23 kg/m2), 18 (75%) were male. Squatting showed the highest flexion angle (99.7°, 47.3°–122°). Cross-legged sitting had the highest abduction angle (28.9°, 9.9°–45.7°) and the largest external rotation angle (62°, 37.6°–81.7°). In the female group, there were trends toward a greater flexion angle (4 out of 10 sitting positions) and a smaller abduction angle (6 out of 9 positions), with P values < 0.05. As to body weight, the overweight participants had a smaller flexion angle but a greater abduction angle, with 5 out of 9 positions having a P value < 0.05. Kinematic data of the transverse plane revealed that the heterogeneity of the rotational angles depended on the sitting position. Conclusions This study provided the functional hip motions of common Asian sitting positions. The kinematic data can be utilized in clinical practice as reference values to determine safe positions. Gender and being overweight affected the hip angles in the sagittal and frontal planes. Trial registration Number TCTR20181021004, retrospectively registered at the Thai Clinical Trials Registry (http//:www.clinicaltrials.in.th).

scholarly journals The Three-Dimensional Morphology of the Patellofemoral Joint and the Normal Predicted Value of Tibial Tuberosity-Trochlear Groove Distance In Chinese Population

2020 ◽  
Author(s):  
Zhe Li ◽  
Guanzhi Liu ◽  
Run Tian ◽  
Ning Kong ◽  
Yue Li ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Tibial Tuberosity ◽  
Trochlear Groove ◽  
Lasso Regression ◽  
Cross Sectional ◽  
P Values ◽  
Anterior Posterior

Abstract Our objective was to obtain normal patellofemoral measurements so as to provide a reference for prosthetic design. Besides, the absolute values and indices of TT-TG distances are still controversial in clinical application. A better method to enable precise clinical applications is still needed.Methods:78 knees of 78 subjects without knee pathologies were included in this cross-sectional study. A CT scan was obtained from all subjects and three-dimensional knee models were constructed using Mimics and SolidWorks software. We measured and analyzed 19 parameters including TT-TG distance and dimensions and shapes of patella, femur, tibia, and trochlea. LASSO regression was used to predict the normal TT-TG distances.Results:The dimensional indexes, TT-TG distance, and femoral aspect ratio of the males were significantly larger than those of females (all P values <0.05). However, after controlling the bias from age, height, and weight, there were no significant differences in TT-TG distances, PAL, and anterior-posterior dimensions between genders (all P values >0.05). The Pearson correlation coefficients between the AFO and other indexes were consistently below 0.3, indicating a none or weak relationship. Similar results were observed for the SA and the Wiberg index. Using LASSO regression, we obtained four parameters to predict TT-TG distance (R2=0.5612, P<0.01) to achieve the optimal accuracy and convenience. Conclusion:The anterior-posterior dimensions of the females were thicker than those of males for the same medial-lateral dimensions. More attention should be paid to not only gender differences but individual differences, especially the anterior condyle and trochlea. Besides, this study provided a new method of predicting TT-TG distance to enable precise clinical diagnoses and guide the medial transfer of the tibial tuberosity.

scholarly journals Three-dimensional motion analysis of hip motions in ten common Asian sitting positions in daily living. Do gender and being overweight affect the range of hip motions?

2021 ◽  
Author(s):  
Phob Ganokroj ◽  
Jirayu Chaowalitwong ◽  
Pichitpol Kerdsomneuk ◽  
Narumol Sudjai ◽  
Pisit Lertwanich ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Motion Analysis ◽  
External Rotation ◽  
Three Dimensional ◽  
Cross Sectional Study ◽  
Flexion Angle ◽  
Abduction Angle ◽  
Female Group ◽  
Cross Sectional ◽  
Kinematic Data

Abstract Background Sitting involves many activities of daily life and requires most motion in the hip joint. Asians have more hip flexion and external rotation motions than Westerners owing to cultural and lifestyle differences. Being aware of the normal range of hip motion is essential in clinical practice. Limited research has focused on the hip motions of common sitting positions. The objective was to determine the hip motions of 10 common sitting positions, and to determine whether gender or being overweight affects the range of hip motions.Methods An experimental cross-sectional study was conducted to determine hip motions by using a standard, three-dimensional, motion-analysis system. Healthy subjects performed 10 sitting positions during 3 trials. All hip-kinematic data were measured on the dominant leg of each participant, except for the right- and left-monk positions (both hips were analyzed). Density plots were constructed and statistical analyses were performed to detect the differences between groups (male and female; non-overweight and overweight).Results The 48 participants comprised 24 males and 24 females. Most were right-leg dominant (45 participants; 93.8%). Of the 22 participants in the overweight group (body mass index ≥ 23 kg/m2), 18 (75%) were male. Squatting showed the highest flexion angle (99.7º; 47.3º–122º). Cross-legged sitting had the highest abduction angle (28.9º; 9.9º–45.7º) and the largest external rotation angle (62º; 37.6º–81.7º). In the female group, there were trends toward a greater flexion angle (4 out of 10 sitting positions) and a smaller abduction angle (6 out of 9 positions), with P values < 0.05. As to body weight, the overweight participants had a smaller flexion angle but a greater abduction angle, with 5 out of 9 positions having a P value < 0.05. Kinematic data of the transverse plane revealed that the heterogeneity of the rotational angles depended on the sitting position.Conclusions This study provided the functional hip motions of common Asian sitting positions. The kinematic data can be utilized in clinical practice as reference values to determine safe positions. Gender and being overweight affected the hip angles in the sagittal and frontal planes.Trial registration: Number TCTR20181021004, retrospectively registered at the Thai Clinical Trials Registry (http://www. clinicaltrials.in.th).

scholarly journals Reliability of hip muscle strength measured in principal and intermediate planes of movement

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11521
Author(s):  
Basilio A.M. Goncalves ◽  
David J. Saxby ◽  
Adam Kositsky ◽  
Rod S. Barrett ◽  
Laura E. Diamond
Keyword(s):  
Muscle Strength ◽  
External Rotation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Hip Strength ◽  
Minimum Detectable Change ◽  
Hip Muscle ◽  
Flexion Extension ◽  
Hip Abduction ◽  
Muscle Actions

Background Muscle strength testing is widely used in clinical and athletic populations. Commercially available dynamometers are designed to assess strength in three principal planes (sagittal, transverse, frontal). However, the anatomy of the hip suggests muscles may only be recruited submaximally during tasks performed in these principal planes. Objective To evaluate the inter-session reliability of maximal isometric hip strength in the principal planes and three intermediate planes. Methods Twenty participants (26.1 ± 2.7 years, 50% female) attended two testing sessions 6.2 ± 1.8 days apart. Participants completed 3-5 maximal voluntary isometric contractions for hip abduction, adduction, flexion, extension, and internal and external rotation measured using a fixed uniaxial load cell (custom rig) and commercial dynamometer (Biodex). Three intermediate hip actions were also tested using the custom rig: extension with abduction, extension with external rotation, and extension with both abduction and external rotation. Results Moderate-to-excellent intraclass correlation coefficients were observed for all principal and intermediate muscle actions using the custom rig (0.72–0.95) and the Biodex (0.85–0.95). The minimum detectable change was also similar between devices (custom rig = 11–31%; Biodex = 9–20%). Bland-Altman analysis revealed poor agreement between devices (range between upper and lower limits of agreement = 77–131%). Conclusions Although the custom rig and Biodex showed similar reliability, both devices may lack the sensitivity to detect small changes in hip strength commonly observed following intervention.

Leader-Member Exchange (LMX) Impact on Work-Home Interference in a South African Commuter Transport Engineering Company

2019 ◽  
Vol 43 ◽  
Author(s):  
Jan Christoff Visagie ◽  
Michael M. Jones ◽  
Herman L. Linde
Keyword(s):  
South African ◽  
Structural Equation ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Leader Member Exchange ◽  
Negative Consequences ◽  
Dyadic Relationship ◽  
Cross Sectional ◽  
Engineering Company ◽  
Member Exchange

The South African workplace is confronted with many leadership challenges, specifically those relating to the employment relationship between subordinates and their supervisors. A high-quality relationship is essential, considering the work-family spillovers employees experience. Limited research has been conducted on the potential positive and negative consequences of the leader-member exchange (LMX) dyadic relationship. In this study, we used a cross-sectional research design, and drew an employee sample (N = 120) from a commuter transport engineering company. A five-point Likert scale was employed and statistical analyses were carried out using the SAS statistical program. We calculated Pearson correlation coefficients and used structural equation modelling to test the proposed conceptual model to indicate possible correlations between the different variables. The main finding of the study was that the nature of the LMX relationship quality in the relevant company appeared to be high and positively related to work-home enrichment but negatively related to work-home conflict and role overload. The article concludes by making a number of suggestions to respond to challenges.

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus

2021 ◽  
pp. 1-6
Author(s):  
Young Jin Jo ◽  
Young Kyun Kim
Keyword(s):  
Range Of Motion ◽  
Female Athletes ◽  
External Rotation ◽  
Preventive Measure ◽  
Control Group ◽  
Knee Valgus ◽  
Strength Ratio ◽  
Flexion Extension ◽  
Hip Abduction ◽  
Single Leg Squat

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.

scholarly journals A Quantitative Comparison of Multispectral Refraction Topography and Autorefractometer in Young Adults

2021 ◽  
Vol 8 ◽  
Author(s):  
Yunru Liao ◽  
Zhenlan Yang ◽  
Zijing Li ◽  
Rui Zeng ◽  
Jing Wang ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
High Agreement ◽  
Intraclass Correlation Coefficients ◽  
Repeatability And Reproducibility ◽  
The Mean

Purpose: Purpose of this study is to evaluate the measuring consistency of central refraction between multispectral refraction topography (MRT) and autorefractometry.Methods: This was a descriptive cross-sectional study including subjects in Sun Yat-sen Memorial Hospital from September 1, 2020, to December 31, 2020, ages 20 to 35 years with a best corrected visual acuity of 20/20 or better. All patients underwent cycloplegia, and the refractive status was estimated with autorefractometer, experienced optometrist and MRT. We analyzed the central refraction of the autorefractometer and MRT. The repeatability and reproducibility of values measured using both devices were evaluated using intraclass correlation coefficients (ICCs).Results: A total of 145 subjects ages 20 to 35 (290 eyes) were enrolled. The mean central refraction of the autorefractometer was −4.69 ± 2.64 diopters (D) (range −9.50 to +4.75 D), while the mean central refraction of MRT was −4.49 ± 2.61 diopters (D) (range −8.79 to +5.02 D). Pearson correlation analysis revealed a high correlation between the two devices. The intraclass correlation coefficient (ICC) also showed high agreement. The intrarater and interrater ICC values of central refraction were more than 0.90 in both devices and conditions. At the same time, the mean central refraction of experienced optometrist was −4.74 ± 2.66 diopters (D) (range −9.50 to +4.75D). The intra-class correlation coefficient of central refraction measured by MRT and subjective refraction was 0.939.Conclusions: Results revealed that autorefractometry, experienced optometrist and MRT show high agreement in measuring central refraction. MRT could provide a potential objective method to assess peripheral refraction.

Validation of the Three-Item Skindex-Mini Among Hidradenitis Suppurativa Patients With Diverse Racial Backgrounds

2020 ◽  
Vol 24 (5) ◽  
pp. 457-460
Author(s):  
Lauren A.V. Orenstein ◽  
Adaugo Amah ◽  
Fiona M. Shaw ◽  
Chao Zhang ◽  
Robert A. Swerlick ◽  
...  
Keyword(s):  
Hidradenitis Suppurativa ◽  
Rating Scale ◽  
Clinical Care ◽  
Pearson Correlation ◽  
Life Quality ◽  
Correlation Coefficients ◽  
Numeric Rating Scale ◽  
Secondary Outcome ◽  
Cross Sectional ◽  
And Function

Background Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that severely impairs patients’ quality of life (QoL). Instruments such as the 10-item Dermatology Life Quality Index and 16-item Skindex-16 have been used to assess QoL in HS; however, it is unknown whether the shorter 3-item Skindex-mini can also provide an accurate assessment of skin-related QoL in patients with HS. Objectives The aim was to assess how well the Skindex-16 correlates with its shorter adaptation, the Skindex-mini, in capturing QoL among patients with HS. Methods This retrospective cross-sectional study included all HS patients seen in the HS Clinic at The Emory Clinic between January 1, 2019, and August 16, 2019. We compared the correlation between the symptom, emotion, and function domains of the Skindex-16 and Skindex-mini using Pearson correlation coefficients (CC). Secondary outcome measures included individual survey item analysis, ItchyQuant scores, and numeric rating scale of pain. Results We identified 108 encounters among 75 unique hidradenitis suppurativa patients (43 black/African American, 18 white, 5 Asian/Pacific Islander, 3 Latino, 4 Other, 2 unknown). Pearson CC between the Skindex-16 and Skindex-mini domain scores for all encounters were 0.770 ( P < .001), 0.787 ( P < .001), and 0.801 ( P < .001) for the symptom, emotion, and function domains, respectively. The mean pain and ItchyQuant scores were 4.14 (SD 3.31) and 3.55 (SD 3.34), respectively. Conclusions The Skindex-mini correlated highly with the Skindex-16 in a racially diverse group of patients with HS. The Skindex-mini is a streamlined QoL instrument that could be practically implemented into routine clinical care among diverse patients presenting to dermatology.

Sign in / Sign up

Export Citation Format

Share Document