scholarly journals Hip-Extensor Strength, Trunk Posture, and Use of the Knee-Extensor Muscles During Running

2016 ◽  
Vol 51 (7) ◽  
pp. 519-524 ◽  
Author(s):  
Hsiang-Ling Teng ◽  
Christopher M. Powers
Keyword(s):  
Muscle Strength ◽  
Sagittal Plane ◽  
Knee Injuries ◽  
Knee Extensor ◽  
Extensor Muscle ◽  
Muscle Performance ◽  
Flexion Angle ◽  
Knee Extensors ◽  
Trunk Flexion ◽  
Trunk Posture

Context: Diminished hip-muscle performance has been proposed to contribute to various knee injuries. Objective: To determine the association between hip-extensor muscle strength and sagittal-plane trunk posture and the relationships among hip-extensor muscle strength and hip- and knee-extensor work during running. Design: Descriptive laboratory study. Setting: Musculoskeletal biomechanical laboratory. Patients or Other Participants: A total of 40 asymptomatic recreational runners, 20 men (age = 27.1 ± 7.0 years, height = 1.74 ± 0.69 m, mass = 71.1 ± 8.2 kg) and 20 women (age = 26.2 ± 5.8 years, height = 1.65 ± 0.74 m, mass = 60.6 ± 6.6 kg), participated. Main Outcome Measure(s): Maximum isometric strength of the hip extensors was assessed using a dynamometer. Sagittal-plane trunk posture (calculated relative to the global vertical axis) and hip- and knee-extensor work (sum of energy absorption and generation) during the stance phase of running were quantified while participants ran over ground at a controlled speed of 3.4 m/s. We used Pearson product moment correlations to examine the relationships among hip-extensor strength, mean sagittal-plane trunk-flexion angle, hip-extensor work, and knee-extensor work. Results: Hip-extensor strength was correlated positively with trunk-flexion angle (r = 0.55, P < .001) and hip-extensor work (r = 0.46, P = .003). It was correlated inversely with knee-extensor work (r = −0.39, P = .01). All the correlations remained after adjusting for sex. Conclusions: Our findings suggest that runners with hip-extensor weakness used a more upright trunk posture. This strategy led to an overreliance on the knee extensors and may contribute to overuse running injuries at the knee.

Clinical Estimation of the Use of the Hip and Knee Extensors During Athletic Movements Using 2D Video

2021 ◽  
pp. 1-5
Author(s):  
Rachel K. Straub ◽  
Alex Horgan ◽  
Christopher M. Powers
Keyword(s):  
Sagittal Plane ◽  
Linear Regression Analysis ◽  
Knee Injuries ◽  
Knee Extensor ◽  
Practical Method ◽  
Movement Behavior ◽  
Knee Extensors ◽  
Deceleration Phase ◽  
Moment Ratio ◽  
Peak Knee

Given that increased use of the knee extensors relative to the hip extensors may contribute to various knee injuries, there is a need for a practical method to characterize movement behavior indicative of how individuals utilize the hip and knee extensors during dynamic tasks. The purpose of the current study was to determine whether the difference between sagittal plane trunk and tibia orientations obtained from 2D video (2D trunk–tibia) could be used to predict the average hip/knee extensor moment ratio during athletic movements. Thirty-nine healthy athletes (15 males and 24 females) performed 6 tasks (step down, drop jump, lateral shuffle, deceleration, triple hop, and side-step-cut). Lower-extremity kinetics (3D) and sagittal plane video (2D) were collected simultaneously. Linear regression analysis was performed to determine if the 2D trunk–tibia angle at peak knee flexion predicted the average hip/knee extensor moment ratio during the deceleration phase of each task. For each task, an increase in the 2D trunk–tibia angle predicted an increase in the average hip/knee extensor moment ratio when adjusted for body mass (all P < .013, R2 = .17–.77). The 2D trunk–tibia angle represents a practical method to characterize movement behavior that is indicative of how individuals utilize the hip and knee extensors during dynamic tasks.

scholarly journals Knee Extensor Muscle Strength And The Depressive Status Among Older Japanese Women: A Cross-sectional Study

2021 ◽  
Vol 53 (8S) ◽  
pp. 196-197
Author(s):  
Ohta Takahisa ◽  
Hiroyuki Sasai ◽  
Narumi Kojima ◽  
Yosuke Osuka ◽  
Kiyoji Tanaka ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Knee Extensor ◽  
Cross Sectional Study ◽  
Japanese Women ◽  
Extensor Muscle ◽  
Sectional Study ◽  
Cross Sectional ◽  
Knee Extensor Muscle Strength

The Association of Obesity With Quadriceps Activation During Sit-to-Stand

2020 ◽  
Vol 100 (12) ◽  
pp. 2134-2143
Author(s):  
Lance M Bollinger ◽  
Amanda L Ransom
Keyword(s):  
Vastus Lateralis ◽  
Knee Extensor ◽  
Quadriceps Muscle ◽  
Knee Extensors ◽  
Emg Activity ◽  
Vastus Medialis ◽  
Trunk Flexion ◽  
Maximal Voluntary Isometric Contraction ◽  
Sit To Stand ◽  
The Mean

Abstract Objective Obesity reduces voluntary recruitment of quadriceps during single-joint exercises, but the effects of obesity on quadriceps femoris muscle activation during dynamic daily living tasks, such as sit-to-stand (STS), are largely unknown. The purpose of this study was to determine how obesity affects quadriceps muscle recruitment during STS. Methods In this cross-sectional study, 10 women who were lean and 17 women who were obese completed STS from a chair with arms crossed over the chest. Three-dimensional motion analysis was used to define 3 distinct phases (I–III) of the STS cycle. The electromyographic (EMG) activity of the vastus medialis, vastus lateralis, and semitendinosus was measured. Results STS duration was greater (3.02 [SD = 0.75] seconds vs 1.67 [SD = 0.28] seconds) and peak trunk flexion angle was lower (28.9 degrees [SD = 10.4 degrees] vs 35.8 degrees [SD = 10.1 degrees]) in the women who were obese than in the women who were lean. The mean EMG activity of the knee extensors increased from phase I to phase II in both groups; however, the mean EMG activities of both the vastus medialis (32.1% [SD = 16.6%] vs 47.3% [SD = 19.6%] maximal voluntary isometric contraction) and the vastus lateralis (31.8% [SD = 19.4%] vs 47.5% [SD = 19.6%] maximal voluntary isometric contraction) were significantly lower during phase II in the women who were obese. The mean EMG activity of the semitendinosus increased throughout STS but was not significantly different between the 2 groups. Coactivation of the semitendinosus and knee extensors tended to be greater in the women who were obese but failed to reach statistical significance. Conclusions Knee extensor EMG amplitude was reduced in women who were obese during STS, despite reduced trunk flexion. Impact Reduced knee extensor recruitment during STS in obesity may redistribute forces needed to complete this task to other joints. Functional movement training may help improve knee extensor recruitment during STS in people who are obese. Lay Summary People with obesity often have low quadriceps muscle strength and impaired mobility during daily activities. This study shows that women who are obese have lower voluntary recruitment of quadriceps when rising from a chair than women who are lean do, which could increase workload on hip or ankle muscles during this important daily task. Quadriceps strengthening exercises might improve the ability to rise from sitting to standing.

scholarly journals Effects of long-term resistance training and simultaneous electro-stimulation on muscle strength and functional mobility in multiple sclerosis

2010 ◽  
Vol 17 (4) ◽  
pp. 468-477 ◽  
Author(s):  
Tom Broekmans ◽  
Machteld Roelants ◽  
Peter Feys ◽  
Geert Alders ◽  
Domien Gijbels ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Resistance Training ◽  
Muscle Strength ◽  
Controlled Trial ◽  
Knee Extensor ◽  
Functional Mobility ◽  
Knee Extensors ◽  
Strength Analysis ◽  
Control Group

Background: Resistance training studies in multiple sclerosis (MS) often use short intervention periods. Furthermore, training efficiency could be optimized by unilateral training and/or electrical stimulation. Objective: To examine the effect(s) of unilateral long-term (20 weeks) standardized resistance training with and without simultaneous electro-stimulation on leg muscle strength and overall functional mobility. Methods: A randomized controlled trial involving 36 persons with MS. At baseline (PRE) and after 10 (MID) and 20 (POST) weeks of standardized (ACSM) light to moderately intense unilateral leg resistance training (RESO, n = 11) only or resistance training with simultaneous electro-stimulation (RESE, n = 11, 100 Hz, biphasic symmetrical wave, 400 µs), maximal isometric strength of the knee extensors and flexors (45°, 90° knee angle) and dynamic (60–180°/s) knee-extensor strength was measured and compared with a control group (CON, n = 14). Functional mobility was evaluated using the Timed Get Up and Go, Timed 25 Foot Walk, Two-Minute Walk Test, Functional Reach and Rivermead Mobility Index. Results: Maximal isometric knee extensor (90°, MID: +10 ± 3%, POST: +10 ± 4%) in RESO and knee flexor (45°, POST: +7 ± 4%; 90°, POST: +9 ± 5%) in RESE strength increased ( p < 0.05) compared with CON but RESO and RESE did not differ. Also, impaired legs responded positively to resistance training (unilateral leg strength analysis) and functional reaching increased significantly in RESO (+18%) compared with CON. Dynamic muscle strength and the remaining functional mobility tests did not change. Conclusion: Long-term light to moderately intense resistance training improves muscle strength in persons with MS but simultaneous electro-stimulation does not further improve training outcome.

scholarly journals An Investigation into the Relation between the Technique of Movement and Overload in Step Aerobics

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Alicja Rutkowska-Kucharska ◽  
Katarzyna Wysocka ◽  
Sławomir Winiarski ◽  
Agnieszka Szpala ◽  
Małgorzata Sobera
Keyword(s):  
Knee Joint ◽  
Joint Angle ◽  
Sagittal Plane ◽  
Flexion Angle ◽  
Trunk Flexion ◽  
Smart System ◽  
Video Cameras ◽  
Reaction Forces ◽  
Joint Flexion ◽  
Dorsal Flexion

The aim of this research was to determine the features of a step workout technique which may be related to motor system overloading in step aerobics. Subjects participating in the research were instructors (n=15) and students (n=15) without any prior experience in step aerobics. Kinematic and kinetic data was collected with the use of the BTS SMART system comprised of 6 calibrated video cameras and two Kistler force plates. The subjects’ task was to perform basic steps. The following variables were analyzed: vertical, anteroposterior, and mediolateral ground reaction forces; foot flexion and abduction and adduction angles; knee joint flexion angle; and trunk flexion angle in the sagittal plane. The angle of a foot adduction recorded for the instructors was significantly smaller than that of the students. The knee joint angle while stepping up was significantly higher for the instructors compared to that for the students. Our research confirmed that foot dorsal flexion and adduction performed while stepping up increased load on the ankle joint. Both small and large angles of knee flexion while stepping up and down resulted in knee joint injuries. A small trunk flexion angle in the entire cycle of step workout shut down dorsal muscles, which stopped suppressing the load put on the spine.

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