scholarly journals Horizontal and Declined Squats in Healthy Individuals: A Study of Kinematic and Muscle Patterns

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Valdeci Carlos Dionisio ◽  
Bruna Maria Silva Azevedo ◽  
Daniela Abrahão Siqueira

Squats are frequently incorporated in physiotherapy programmes and performed in different ways. Accordingly, muscle and kinematic patterns also differ. The objective was to compare the kinematics and EMG patterns of the major muscles of knee and ankle joints during different squat exercises on horizontal (HP) and 25° decline (DP) boards. Seventeen healthy individuals performed squats on HP and DP with bilateral support and restriction of trunk movements in the sagittal plane. The knee and ankle angular displacements in the sagittal plane and the EMG activities of the major muscles of the lower limb in four subphases of movement were recorded and analyzed. For the descending phase of the HP squats, the angular excursion, as well as the initial and final positions, was smaller for the knee (P<0.05) but larger for the ankle (P=0.01). For the ascending phase of the HP squats, the initial and final positions were larger for the ankle (P<0.02) and the final position was smaller for the knee (P=0.05). All muscles remained activated and showed similarity between the tasks (P>0.44), except for the tibialis anterior in both squat exercises (P<0.03). The HP and DP squats produced different kinematics (knee and ankle joints) but did not modify the EMG strategy for both movement phases.

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Massimiliano Pau ◽  
Bruno Leban ◽  
Michela Deidda ◽  
Federica Putzolu ◽  
Micaela Porta ◽  
...  

The majority of people with Multiple Sclerosis (pwMS), report lower limb motor dysfunctions, which may relevantly affect postural control, gait and a wide range of activities of daily living. While it is quite common to observe a different impact of the disease on the two limbs (i.e., one of them is more affected), less clear are the effects of such asymmetry on gait performance. The present retrospective cross-sectional study aimed to characterize the magnitude of interlimb asymmetry in pwMS, particularly as regards the joint kinematics, using parameters derived from angle-angle diagrams. To this end, we analyzed gait patterns of 101 pwMS (55 women, 46 men, mean age 46.3, average Expanded Disability Status Scale (EDSS) score 3.5, range 1–6.5) and 81 unaffected individuals age- and sex-matched who underwent 3D computerized gait analysis carried out using an eight-camera motion capture system. Spatio-temporal parameters and kinematics in the sagittal plane at hip, knee and ankle joints were considered for the analysis. The angular trends of left and right sides were processed to build synchronized angle–angle diagrams (cyclograms) for each joint, and symmetry was assessed by computing several geometrical features such as area, orientation and Trend Symmetry. Based on cyclogram orientation and Trend Symmetry, the results show that pwMS exhibit significantly greater asymmetry in all three joints with respect to unaffected individuals. In particular, orientation values were as follows: 5.1 of pwMS vs. 1.6 of unaffected individuals at hip joint, 7.0 vs. 1.5 at knee and 6.4 vs. 3.0 at ankle (p < 0.001 in all cases), while for Trend Symmetry we obtained at hip 1.7 of pwMS vs. 0.3 of unaffected individuals, 4.2 vs. 0.5 at knee and 8.5 vs. 1.5 at ankle (p < 0.001 in all cases). Moreover, the same parameters were sensitive enough to discriminate individuals of different disability levels. With few exceptions, all the calculated symmetry parameters were found significantly correlated with the main spatio-temporal parameters of gait and the EDSS score. In particular, large correlations were detected between Trend Symmetry and gait speed (with rho values in the range of –0.58 to –0.63 depending on the considered joint, p < 0.001) and between Trend Symmetry and EDSS score (rho = 0.62 to 0.69, p < 0.001). Such results suggest not only that MS is associated with significantly marked interlimb asymmetry during gait but also that such asymmetry worsens as the disease progresses and that it has a relevant impact on gait performances.


2021 ◽  
Vol 86 ◽  
pp. 150-156
Author(s):  
L. van Kouwenhove ◽  
G.J. Verkerke ◽  
K. Postema ◽  
R. Dekker ◽  
J.M. Hijmans

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alexander Agboola-Dobson ◽  
Guowu Wei ◽  
Lei Ren

Recent advancements in powered lower limb prostheses have appeased several difficulties faced by lower limb amputees by using a series-elastic actuator (SEA) to provide powered sagittal plane flexion. Unfortunately, these devices are currently unable to provide both powered sagittal plane flexion and two degrees of freedom (2-DOF) at the ankle, removing the ankle’s capacity to invert/evert, thus severely limiting terrain adaption capabilities and user comfort. The developed 2-DOF ankle system in this paper allows both powered flexion in the sagittal plane and passive rotation in the frontal plane; an SEA emulates the biomechanics of the gastrocnemius and Achilles tendon for flexion while a novel universal-joint system provides the 2-DOF. Several studies were undertaken to thoroughly characterize the capabilities of the device. Under both level- and sloped-ground conditions, ankle torque and kinematic data were obtained by using force-plates and a motion capture system. The device was found to be fully capable of providing powered sagittal plane motion and torque very close to that of a biological ankle while simultaneously being able to adapt to sloped terrain by undergoing frontal plane motion, thus providing 2-DOF at the ankle. These findings demonstrate that the device presented in this paper poses radical improvements to powered prosthetic ankle-foot device (PAFD) design.


2016 ◽  
Vol 116 (4) ◽  
pp. 1848-1858 ◽  
Author(s):  
Ryan M. Peters ◽  
Monica D. McKeown ◽  
Mark G. Carpenter ◽  
J. Timothy Inglis

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults.


2021 ◽  
Vol 20 (2) ◽  
pp. 37-44
Author(s):  
V. N. Zasimovich ◽  
V. V. Zinchuk ◽  
N. N. Ioskevich

Introduction. Reperfusion-reoxygenation syndrome (RRS) after revascularization of the lower limbs in obliterating atherosclerosis of the arteries is accompanied by a violation of the oxygen transport function of the blood (OTFB) and the content of gas transmitters (GTs). Reperfusion injury affects not only the tissues of the lower limbs, but also of anatomically distant organs, which supposes that effective RRS correction is required. Aim. To study the effect of Corvitin on the OTFB parameters and the content of GT of nitrogen monoxide (NO) and hydrogen sulfide (H2S) in the venous blood of the forearm after revascularization of the lower limb in chronic atherosclerotic occlusion of the superficial femoral artery (SFA). Materials and methods. The study included 118 male patients. Revascularization of the lower limb was carried out by the method of loop endaterectomy from the SFA. Patients of group I (n=52) received traditional medication, 51 patients of group II additionally received Corvitin. In the blood from the vein of the elbow bend before the operation, on the 3rd and 8th days after it, the indices of OTFB and GTs were determined. Results. In group I, on the 3rd day after surgery, pO2 increased in relation to healthy individuals by 5.2–18.5%, while pCO2 decreased by 4.8–6.7%, depending on the stage of initial ischemia. The concentrations of NO and H2S increased by 9.2–50.1% and 9.2–21.1%, respectively. The increase in the parameters of hyperoxemia, hypocapnemia and GT after the return of blood circulation decreases with the use of Corvitin (p˂0.05). By the end of the early postoperative period, the indicators of OTFB and GT not only return to their initial values, but also do not significantly differ from the group of healthy individuals (p˃0.05). Conclusion. The use of Corvitin effectively corrects violations of OTFB and GT during ischemia-reperfusion of the lower limbs, which prevents tissue reperfusion damage.


2000 ◽  
Author(s):  
Nader Arafati ◽  
Jean Yves Lazennec ◽  
Roger Ohayon

Abstract Human movement modeling has been the object of much research for the past 30 years. In these models the position of foot link was fixed on the ground. We propose to model the feet links as variable, since the position of foot pressure center changes from heel to toes. The ground reaction forces could also be analyzed in real time. We examined this model for some static postures. In standing anatomical position, the maximum articular forces are localized in hip and knee joints. In sagittal plane, the ground reaction force vectors are positioned nearly under ankle joints. The pathological postures like body with pes cavus or with global spine kyphosis increase the articular and muscular forces. In these cases, the position of ground reaction force vectors is moved toward the toes.


2013 ◽  
Vol 19 (3) ◽  
pp. 620-626 ◽  
Author(s):  
Camilla Zamfolini Hallal ◽  
Nise Ribeiro Marques ◽  
Edgar Ramos Vieira ◽  
Denis Brunt ◽  
Deborah Hebling Spinoso ◽  
...  

The purpose of this study was to investigate the influence of daily cognitive task on stiffness of old and young female adults during the gait. The study included 17 physically active younger and 18 older women, with low risk of falls. The volunteers were asked to walk on the treadmill at two different gait conditions: normal gait and functional dual-task gait. The electromyographic signals were collected of the lower limb muscles. The percentage of coactivation for the tibialis anterior/gastrocnemius lateralis and tibialis anterior/soleus were significantly higher in elderly than in younger in the normal gait and dual-task gait. Our results suggest that the elderly have a greater stiffness in the ankle joint during gait normal and daily dual task gait. Thus, we conclude that challenging cognitively situations during the gait may increase the risk of falls in this population.


Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 141 ◽  
Author(s):  
Rob Van der Straaten ◽  
Amber K. B. D. Bruijnes ◽  
Benedicte Vanwanseele ◽  
Ilse Jonkers ◽  
Liesbet De Baets ◽  
...  

This study evaluates the reliability and agreement of the 3D range of motion (ROM) of trunk and lower limb joints, measured by inertial measurement units (MVN BIOMECH Awinda, Xsens Technologies), during a single leg squat (SLS) and sit to stand (STS) task. Furthermore, distinction was made between movement phases, to discuss the reliability and agreement for different phases of both movement tasks. Twenty healthy participants were measured on two testing days. On day one, measurements were conducted by two operators to determine the within-session and between-operator reliability and agreement. On day two, measurements were conducted by the same operator, to determine the between-session reliability and agreement. The SLS task had lower within-session reliability and agreement compared with between-session and between-operator reliability and agreement. The reliability and agreement of the hip, knee, and ankle ROM in the sagittal plane were good for both phases of the SLS task. For both phases of STS task, within-session reliability and agreement were good, and between-session and between-operator reliability and agreement were lower in all planes. As both tasks are physically demanding, differences may be explained by inconsistent movement strategies. These results show that inertial sensor systems show promise for use in further research to investigate (mal)adaptive movement strategies.


Sign in / Sign up

Export Citation Format

Share Document