scholarly journals New Training Tasks for Stepwise Loading in Isometric Bodyweight Squat with Active Posture Control

2021 ◽  
Vol 11 (17) ◽  
pp. 8151
Author(s):  
Tetsuro Kitamura ◽  
Yukako Ishida ◽  
Shinji Tsukamoto ◽  
Manabu Akahane ◽  
Tomoo Mano ◽  
...  
Keyword(s):  
Athletic Training ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Knee Flexion ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Foot Pressure ◽  
Training Strategy ◽  
Center Of Foot Pressure ◽  
Stepwise Loading

Isometric bodyweight squats are fundamental exercises in athletic training and rehabilitation. Previously, we measured muscle activity in a normal squat posture (NSP) and a squat posture with the center of foot pressure (COP) intentionally shifted forward as far as possible (forward-shifted posture: FSP), and the muscle activity patterns varied significantly according to the COP location. This study focused on stepwise loading as a training strategy. Ten healthy male participants performed isometric bodyweight squats in a previous study, adopting the NSP and FSP, with three knee flexion angles (30°, 60°, and 90°). The muscle activities of the vastus medialis (VM), semitendinosus, tibialis anterior (TA), and gastrocnemius muscle lateral head were measured using surface electromyogram. This study further explored the relationship between COP shifting and knee flexion angles on electromyogram changes using three-dimensional diagrams. In one-way repeated measures analysis of variance by ranks, knee flexion angles affected the muscle activities of the VM and TA in the NSP and muscle activities of the VM in the FSP. Combining these findings, stepwise loading tasks were created to train individual target muscles. The ten male participants examined all the tasks, and the feasibility was confirmed accordingly.

Effect of Knee Joint Angle on Regional Hamstrings Activation During Isometric Knee-Flexion Exercise

2020 ◽  
pp. 1-6
Author(s):  
Raki Kawama ◽  
Masamichi Okudaira ◽  
David H. Fukuda ◽  
Hirohiko Maemura ◽  
Satoru Tanigawa
Keyword(s):  
Knee Joint ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Knee Flexion ◽  
Muscle Activation ◽  
Joint Angle ◽  
Motor Nerve ◽  
Activity Level ◽  
Activity Levels ◽  
Knee Joint Angle

Context: Each hamstring muscle is subdivided into several regions by multiple motor nerve branches, which implies each region has different muscle activation properties. However, little is known about the muscle activation of each region with a change in the knee joint angle. Understanding of regional activation of the hamstrings could be helpful for designing rehabilitation and training programs targeted at strengthening a specific region. Objective: To investigate the effect of knee joint angle on the activity level of several regions within the individual hamstring muscles during isometric knee-flexion exercise with maximal effort (MVCKF). Design: Within-subjects repeated measures. Setting: University laboratory. Participants: Sixteen young males with previous participation in sports competition and resistance training experience. Intervention: The participants performed 2 MVCKF trials at each knee joint angle of 30°, 60°, and 90°. Outcome Measures: Surface electromyography was used to measure muscle activity in the proximal, middle, and distal regions of the biceps femoris long head (BFlh), semitendinosus, and semimembranosus of hamstrings at 30°, 60°, and 90° of knee flexion during MVCKF. Results: Muscle activity levels in the proximal and middle regions of the BFlh were higher at 30° and 60° of knee flexion than at 90° during MVCKF (all: P < .05). Meanwhile, the activity levels in the distal region of the BFlh were not different among all of the evaluated knee joint angles. In semitendinosus and semimembranosus, the activity levels were higher at 30° and 60° than at 90°, regardless of region (all: P < .05). Conclusion: These findings suggest that the effect of knee joint angle on muscle activity level differs between regions of the BFlh, whereas that is similar among regions of semitendinosus and semimembranosus during MVCKF.

Effect of Different Insole Materials on Kinetic and Kinematic Variables of the Walking Gait in Healthy People

2018 ◽  
Vol 108 (5) ◽  
pp. 390-396 ◽  
Author(s):  
Ramadan Özmanevra ◽  
Salih Angin ◽  
İzge H. Günal ◽  
Ata Elvan
Keyword(s):  
Repeated Measures ◽  
Knee Flexion ◽  
Reaction Force ◽  
Three Dimensional ◽  
Ankle Dorsiflexion ◽  
Healthy People ◽  
Walking Gait ◽  
System A ◽  
Significant Difference ◽  
Analysis System

Background: There is a lack of data that could address the effects of off-the-shelf insoles on gait variables in healthy people. Methods: Thirty-three healthy volunteers ranging in age from 18 to 35 years were included to this study. Kinematic and kinetic data were obtained in barefoot, shoe-only, steel insole, silicone insole, and polyurethane insole conditions using an optoelectronic three-dimensional motion analysis system. A repeated measures analysis of variance test was used to identify statistically significant differences between insole conditions. The alpha level was set at P &lt; .05 Results: Maximum knee flexion was higher in the steel insole condition (P &lt; .0001) compared with the silicone insole (P = .001) and shoe-only conditions (P = .032). Reduced maximum knee flexion was recorded in the polyurethane insole condition compared with the shoe-only condition (P = .031). Maximum knee flexion measured in the steel insole condition was higher compared to the barefoot condition (P = .020). Higher maximum ankle dorsiflexion was observed in the barefoot condition, and there were significant differences between the polyurethane insole (P &lt; .0001), silicone insole (P = .001), steel insole (P = .002), and shoe conditions (P = .004). Least and highest maximum ankle plantarflexion were detected in the steel insole and silicone insole conditions, respectively. Maximum ankle plantarflexion in the barefoot and steel insole conditions (P = .014) and the barefoot and polyurethane insole conditions (P = .035) were significant. There was no significant difference between conditions for ground reaction force or joint moments. Conclusions: Insoles made by different materials affect maximum knee flexion, maximum ankle dorsiflexion, and maximum ankle plantarflexion. This may be helpful during the decision-making process when selecting the insole material for any pathological conditions that require insole prescription.

Neuromuscular strategies in the paretic leg during curved walking in individuals post-stroke

2011 ◽  
Vol 106 (1) ◽  
pp. 280-290 ◽  
Author(s):  
Karine Duval ◽  
Kathryn Luttin ◽  
Tania Lam
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Activity Patterns ◽  
Neuromuscular Control ◽  
Gluteus Medius ◽  
Medial Gastrocnemius ◽  
Foot Pressure ◽  
Post Stroke ◽  
Stroke Group ◽  
Path Curvature

Reduced flexibility over the neuromotor control of paretic leg muscles may impact the extent to which individuals post-stroke modulate their muscle activity patterns to walk along curved paths. The purpose of this study was to compare lower-limb movements and neuromuscular strategies in the paretic leg of individuals with stroke with age-matched controls during curved walking. Participants walked at their preferred walking velocity along four different paths of increasing curvature, while lower-limb kinematics and muscle activity were recorded. A second group of able-bodied individuals walked along the four paths, matching the walking speed of the stroke group. The stroke group showed reduced lower-limb joint excursion and disordered modulation of foot pressure during curved walking, accompanied by reduced modulation of muscle activity patterns. In the inner leg of the curve in control subjects, the posteromedial muscles (medial gastrocnemius and medial hamstrings) showed decreased electromyographic amplitude as path curviture increased. Conversely, activity of the posterolateral musculature of the outer leg was decreased with increasing path curvature. Activity in the tibialis anterior and gluteus medius was also modulated with path curvature. However, in the stroke group, we found reduced modulation of muscle activity in the paretic leg during curved walking. The extent of modulation was also associated with the level of physical impairment due to stroke. The results of this study provide further knowledge about neuromuscular control of locomotor adaptations post-stroke.

More than a footwedge: Golf-specific footwear alters muscle activation patterns during standing balance

2020 ◽  
pp. 175433712093826
Author(s):  
Samuel J Wilson ◽  
Jacob R Gdovin ◽  
Charles C Williams ◽  
Paul T Donahue ◽  
James G Mouser ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Activity Patterns ◽  
Standing Balance ◽  
Medial Gastrocnemius ◽  
Extrinsic Factors ◽  
Activation Patterns ◽  
Intrinsic Factors ◽  
Muscle Activation Patterns

Within a golf swing, one aspect that stands out in each phase is the ability to maintain balance. Previous reports suggest that extrinsic factors, such as footwear, and intrinsic factors, such as muscular exertion level, have detrimental effects on human postural control. However, no studies have examined the effects of modern golf footwear on muscle activity of the lower extremity. Thus, the purpose of this study was to examine differences in muscle activity when walking for extended durations in golf footwear. Participants were tested for balance prior to walking sessions and then every 60 min until the 240th minute in three types of golf footwear; dress shoes, tennis shoes, and casual shoes, and barefoot. Mean muscle activity during balance testing of the vastus medialis, semitendinosus, tibialis anterior, and medial gastrocnemius was examined using a 4 × 5 repeated measures analysis of variance to identify differences within time and footwear types. Increases in muscle activity were observed after the second hour. Footwear differences were observed in the dress shoe and tennis shoe style relative to the casual style, and primarily attributed to the increased sole/midsole thickness, and increased mass of the dress shoe. These results suggest that golf footwear characteristics may alter muscle activity patterns during standing balance.

Hip Abductor and Adductor Muscles Activity Patterns During Landing After Anterior Cruciate Ligament Injury

2019 ◽  
Vol 28 (8) ◽  
pp. 871-876 ◽  
Author(s):  
Komeil Dashti Rostami ◽  
Aynollah Naderi ◽  
Abbey Thomas
Keyword(s):  
Anterior Cruciate Ligament ◽  
Athletic Training ◽  
Muscle Activity ◽  
Cruciate Ligament ◽  
Activity Patterns ◽  
Acl Injury ◽  
Initial Contact ◽  
Adductor Muscles ◽  
Anterior Cruciate ◽  
Adductor Longus

Context: Hamstring and quadriceps activity adaptations are well known in individuals with anterior cruciate ligament deficiency (ACLD) and reconstructed (ACLR) to potentially compensate for knee joint instability. However, few studies have explored hip muscles activity patterns after ACL injury. Objective: To examine the activation characteristics of gluteus medius (GMED) and adductor longus in ACLR and ACLD subjects compared with controls. Design: Case–control study. Setting: Athletic training room and university lab. Participants: Twelve healthy and 24 ACL-injured (12 ACLR and 12 ACLD) recreationally active male volunteers. Interventions: Surface electromyography of the GMED and adductor longus were recorded during a single-leg vertical drop landing and normalized to maximum voluntary isometric contractions. Main Outcome Measures: Preparatory and reactive muscle activity and coactivation were analyzed from 100 milliseconds prior to initial contact to 250 milliseconds postcontact. Results: During reactive activity, ACL-injured (ACLR and ACLD) participants demonstrated significantly lower peak GMED activity compared with controls (F = 4.33, P = .02). In addition, ACLR participants exhibited significantly lower reactive GMED:adductor longus coactivation muscle activity compared with controls (F = 4.09, P = .03). Conclusion: Our findings suggest neuromuscular adaptations of the hip musculature are present in people at least 2 years from ACL injury. GMED activation exercises should be considered in designing rehabilitation programs for ACL-injured individuals.

Electromyographic Analysis of Hip and Trunk Muscle Activity During Side Bridge Exercises in Subjects With Gluteus Medius Weakness

2020 ◽  
pp. 1-6
Author(s):  
Kyung-eun Lee ◽  
Seung-min Baik ◽  
Chung-hwi Yi ◽  
Oh-yun Kwon ◽  
Heon-seock Cynn
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
Knee Flexion ◽  
Gluteus Maximus ◽  
Random Order ◽  
Gluteus Medius ◽  
Surface Emg ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Abdominal Muscles

Context: Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the best of our knowledge, no previous research has investigated EMG amplitude in the hip and trunk muscles during side bridge exercise in subjects with Gmed weakness. Objective: The purpose of this study was to examine the EMG activity of the hip and trunk muscles during 3 variations of the side bridge exercise (side bridge, side bridge with knee flexion, and side bridge with knee flexion and hip abduction of the top leg) in subjects with Gmed weakness. Design: Repeated-measures experimental design. Setting: Research laboratory. Patients: Thirty subjects (15 females and 15 males) with Gmed weakness participated in this study. Intervention: Each subject performed 3 variations of the side bridge exercise in random order. Main Outcome Measures: Surface EMG was used to measure the muscle activities of the rectus abdominis, external oblique, longissimus thoracis, multifidus, Gmed, gluteus maximus, and tensor fasciae latae (TFL), and Gmed/TFL muscle activity ratio during 3 variations of the side bridge exercise. Results: There were significant differences in Gmed (F2,56 = 110.054, P < .001), gluteus maximus (F2,56 = 36.416, P < .001), and TFL (F2,56 = 108.342, P < .001) muscles among the 3 side bridge exercises. There were significant differences in the Gmed/TFL muscle ratio (F2,56 = 20.738, P < .001). Conclusion: Among 3 side bridge exercises, the side bridge with knee flexion may be effective for the individuals with Gmed weakness among 3 side bridge exercises to strengthen the gluteal muscles, considering the difficulty of the exercise and relative contribution of Gmed and TFL.

scholarly journals Characteristics of Muscle Activity of Lower Leg on Maximum Lateral Shift of Center of Foot Pressure in the Elderly

2005 ◽  
Vol 20 (4) ◽  
pp. 253-257
Author(s):  
Yahiko TAKEUCHI ◽  
Yoshihiro SHIMOMURA ◽  
Koichi IWANAGA ◽  
Tetsuo KATSUURA
Keyword(s):  
Muscle Activity ◽  
The Elderly ◽  
Lower Leg ◽  
Lateral Shift ◽  
Foot Pressure ◽  
Center Of Foot Pressure

Are muscle fibers within fish myotomes activated synchronously? Patterns of recruitment within deep myomeric musculature during swimming in largemouth bass

1995 ◽  
Vol 198 (3) ◽  
pp. 805-815 ◽  
Author(s):  
B Jayne ◽  
G Lauder
Keyword(s):  
Largemouth Bass ◽  
Muscle Activity ◽  
Micropterus Salmoides ◽  
Activity Patterns ◽  
Three Dimensional ◽  
Significant Heterogeneity ◽  
X Rays ◽  
Horizontal Septum ◽  
Vertical Row ◽  
Longitudinal Position

The myomeric axial musculature of fish has a complex three-dimensional morphology, yet within-myomere motor patterns have not been examined to determine whether all portions of each myomere are activated synchronously during locomotion. To gain insight into recruitment patterns in the deep myomeric musculature of fish, we implanted a series of fine-wire electrodes arranged in a vertical row of six electrodes and a longitudinal row of three electrodes on both the left and right sides of each of five largemouth bass (Micropterus salmoides). After recording electromyograms (EMGs) during the burst-and-glide swimming of each fish, post-mortem dissections and X-rays determined the location of electrodes with respect to (1) the longitudinal position (by counting the underlying vertebrae), (2) the position of the myomere containing the electrode, and (3) the portion within each myomere containing an electrode. Because of the convoluted overlapping shape of the myomeres, electrodes within the vertical row of sites could be located in any one of six different myomeres. Thus, we compared muscle activity for locations with a constant longitudinal position and differing myomeric position (vertical row) and among sites with both variable longitudinal and myomeric positions. We detected significant heterogeneity in EMG onset times for sites within the vertical row of electrodes; however, the durations of the EMGs from different sites were similar. EMG onset times at more posterior longitudinal positions preceded those of more anterior longitudinal positions when electrodes of the latter site were within a more posterior myomere. Thus, the timing of EMGs was consistent with the posterior propagation of muscle activity via the sequential activation of myomeres rather than the simultaneous activation of all contractile tissue within the longitudinal span of a single vertebra. In addition, extreme epaxial and hypaxial portions of myomeres showed distinct activity patterns which did not necessarily correlate with activity in the central myomeric fibers nearer the horizontal septum.

Predicting spatial activity patterns in a neural map from a probabilistic atlas of 3-D reconstructed neurons

1995 ◽  
Vol 53 ◽  
pp. 812-813
Author(s):  
G. Jacobs ◽  
F. Theunissen
Keyword(s):  
Activity Patterns ◽  
Three Dimensional ◽  
Sensory System ◽  
Neural System ◽  
Probabilistic Atlas ◽  
Uniform Sample ◽  
Dimensional Reconstruction ◽  
The Time Domain ◽  
And Function ◽  
Visualization Techniques

In order to understand how the algorithms underlying neural computation are implemented within any neural system, it is necessary to understand details of the anatomy, physiology and global organization of the neurons from which the system is constructed. Information is represented in neural systems by patterns of activity that vary in both their spatial extent and in the time domain. One of the great challenges to microscopists is to devise methods for imaging these patterns of activity and to correlate them with the underlying neuroanatomy and physiology. We have addressed this problem by using a combination of three dimensional reconstruction techniques, quantitative analysis and computer visualization techniques to build a probabilistic atlas of a neural map in an insect sensory system. The principal goal of this study was to derive a quantitative representation of the map, based on a uniform sample of afferents that was of sufficient size to allow statistically meaningful analyses of the relationships between structure and function.

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