Crack For Muscle And Motion Software.epub
Abdul Soumphonphakdy
Rationale: There are several methods to measure cardiomyocyte and muscle contraction, but these require customized hardware, expensive apparatus, and advanced informatics or can only be used in single experimental models. Consequently, data and techniques have been difficult to reproduce across models and laboratories, analysis is time consuming, and only specialist researchers can quantify data.
Comparing the available electromyography (EMG) and the related uncertainties with the space of muscle forces potentially driving the same motion can provide insights into understanding human motion in healthy and pathological neuromotor conditions. However, it is not clear how effective the available computational tools are in completely sample the possible muscle forces. In this study, we compared the effectiveness of Metabolica and the Null-Space algorithm at generating a comprehensive spectrum of possible muscle forces for a representative motion frame. The hip force peak during a selected walking trial was identified using a lower-limb musculoskeletal model. The joint moments, the muscle lever arms, and the muscle force constraints extracted from the model constituted the indeterminate equilibrium equation at the joints. Two spectra, each containing 200,000 muscle force samples, were calculated using Metabolica and the Null-Space algorithm. The full hip force range was calculated using optimization and compared with the hip force ranges derived from the Metabolica and the Null-Space spectra. The Metabolica spectrum spanned a much larger force range than the NS spectrum, reaching 811N difference for the gluteus maximus intermediate bundle. The Metabolica hip force range exhibited a 0.3-0.4 BW error on the upper and lower boundaries of the full hip force range (3.4-11.3 BW), whereas the full range was imposed in the NS spectrum. The results suggest that Metabolica is well suited for exhaustively sample the spectrum of possible muscle recruitment strategy. Future studies will investigate the muscle force range in healthy and pathological neuromotor conditions.
Once calibration was complete, each participant was video-recorded to allow for visual data to be captured alongside Xsens motion data. At this point, the families had a discussion as to whether a parent would remain at the appointment or leave the child or a mix. However, if parents attended for the appointment, they were not allowed to interfere or assist with any assessment or data collection.
During the assessment period, any events such as falls or the need for recalibration were documented. Recalibration of the motion capture suit was carried out as and when required in accordance with the quality of data being collected and recorded. After the above recordings and data collection, the Xsens suit was removed, sensors cleaned and recharged for the next participant.
Each participant performed a deep squat with the upper extremities raised while beingrecorded by a digital video camera (HC-V480MS, Panasonic, 30fps, Osaka, Japan) from the leftand right. Two-dimensional motion analysis was then performed using motion analysis software(Kinovea, 0.8.27, Boston, MA, USA). Reflective markers were attached to the left and rightacromion, superior anterior iliac spine, superior posterior iliac spine, seventh cervicalspinous process, fifth lumbar spinous process, greater trochanter, lateral epicondyle of thefemur, fibula head, lateral malleolus, base of the fifth metatarsal bone, and head of thefifth metatarsal bone. The angles of ankle dorsiflexion, knee flexion, hip flexion, pelvicposterior tilt, and trunk anterior tilt at maximum squat depth were calculated. Ankledorsiflexion was measured as the angle between the line connecting the fibula head and thecalcaneus and the line connecting the base and head of the fifth metatarsal bone. Kneeflexion was measured as the angle between the line connecting the greater trochanter and thelateral epicondyle of the femur and the line connecting the fibula head and the lateralmalleolus. Hip flexion was measured as the angle between the line perpendicular to the lineconnecting the superior anterior iliac spine and superior posterior iliac spine and the lineconnecting the greater trochanter and the lateral epicondyle of the femur. Pelvic posteriortilt was measured as the angle between the line connecting the superior anterior iliac spineand the superior posterior iliac spine and an imaginary line parallel to the floor. Trunkanterior tilt was measured as the angle between the line connecting the seventh cervicalspinous process and the fifth lumbar spinous process and an imaginary line perpendicular tothe floor.
Muscle activity in the quadriceps and gluteal muscles is important and depends on thequality and quantity of movement4, 6). Hip and knee flexion angles duringsquatting may be low due to muscle fatigue and muscle weakness9, 12). In the present study,there was no correlation between knee extension strength, hip flexion strength, and maximumsquat depth. Based on the results of the present study, muscle strength is related to thealignment of the frontal plane, but not to the maximum angle of the sagittal plane.
By examining the relationship between the movements of the left and right side of the bodyand the ROM of various joints in a deep squat, it was found that there was a correlationbetween the side with the smaller ROM and the joint angle during movement. For example, inone participant, the ankle dorsiflexion angle was related to the ROM of right ankledorsiflexion and right knee flexion, which were smaller than on the left side, and the ROMof right ankle dorsiflexion affected the knee flexion angle on both sides. It seems that theside with smaller ROM tends to hinder overall movement because the squatting motion issymmetrical by nature.
Knee flexion angle was related to the ROM of ankle dorsiflexion, and hip flexion angle wasrelated to the ROM of ankle dorsiflexion and knee flexion. The mobility of lower joints maydetermine the ROM of joints during deep squats. The same phenomenon is observed in othermotions; upper joint movement is limited by the movement of lower joints being limited14, 15). In addition, it was suggested in the present study that ankledorsiflexion is an important factor that determines the ROM of deep squats, as indicated inprevious studies.
In terms of contralateral relationships, the ROM of ankle dorsiflexion did not correlatewith the ankle dorsiflexion angle on the same side, but did correlate with that on thecontralateral side. Therefore, when motion is analyzed from one side, the fact that thelimiting factor for movement may not the ROM of the observed side but rather that of thejoints on the opposite side must not be overlooked.
The present study showed that the ankle dorsiflexion angle in a deep squat is smaller thanthe maximum ROM of ankle dorsiflexion. During the measurement position during weight-bearingstanding, the feet were spread back and forth so that there was almost no influence from theROM on the side where measurements were not made. However, during deep squats, it isnecessary to perform ankle dorsiflexion, knee flexion, and hip flexion while keeping thecenter of gravity within the base of support made by the feet on both sides, and it isdifficult to tilt the lower leg anteriorly to the maximum ROM. Limiting the ROM can hinderjoint motion during deep squats, but it should be noted that full ROM is not necessary formotion.
One limitation of the present study is that motion analysis was not performed in 3D, so theneither the motion of the horizontal and frontal planes nor the process of motion could beanalyzed. The relationships between the ROM of various joints could be analyzed in moredetail by studying the displacement of each joint during motion in a posture change from astanding position. In addition to the items measured this time, it has been reported thatthe ankle dorsiflexor muscle strength was related to the medial knee displacement duringsquat16). However, in this study, theankle dorsiflexion muscle strength was not measured because the hip and knee muscle strengthwere the main targets. Including this item may have provided more suggestions.
In addition to the acute effect of SS duration on maximum strength and performance, the prolonged effect of SS is also vital to athletes and coaches on sports field. Ryan et al. investigated the effect of 2, 4, and 8-min SS on the plantar flexor group and reported that the decrease in muscle strength and increase in ROM recovered within 10 min [13], and the decrease in musculotendinous stiffness recovered within 10 min after 2-min SS or 20 min after 4- or 8-min SS [14]. In addition, Mizuno et al. investigated the effect of 5-min SS on the plantar flexor group and reported that the decrease in muscle strength recovered within 10 min [15], but the increase in range of motion (ROM) was sustained for >30 min after SS [16]. However, previous studies investigated the prolonged effect of SS, with
There was no significant interaction and main effect of the shear elastic modulus, suggesting that 20-s SS has no effect on the shear elastic modulus. Previous studies have demonstrated a significant decrease in the shear elastic modulus of MG after 2- and 6-min SS [17, 18, 20, 21]. Conversely, this study reported no significant change because SS duration (20 s) used in the current study was much shorter than that used in previous studies [17, 18, 20, 21]. Therefore, we consider that 20-s SS is insufficient to decrease the shear elastic modulus in the medial GM. The previous study identified that increased muscle stiffness may increase the risk of muscle strain and damage [30]. Therefore, in the context of preventing muscle strain and damage, SS duration of 20 s is insufficient.
In addition, we observed no significant interaction or main effect, suggesting that 20-s SS does not affect the concentric or eccentric contraction torque. To explain stretching-induced force deficit, a previous study proposed two primary factors: neural factors (altered motor control strategies or reflex sensitivity) and mechanical factors (changes in muscle stiffness) [12]. Kay et al. reported that 3-min SS resulted in a change in the neurological factors and a decrease in the concentric contraction torques [11]. In addition, mechanical changes of the muscle are involved in stretching-induced force deficit after SS because the muscle activity did not decrease after 60-s SS [31]. In the current study, we did not observe a decrease in the concentric contraction torque after SS. This is likely due to a lack of neurological and mechanical changes in the relatively short SS duration of 20-s, as well as an unaffected afferent contraction strength. Conversely, a previous study suggested that the eccentric contraction torque was not related to the stiffness of the muscle tendon complex [32]. According to Cramer et al., the stiffness of the muscle tendon complex decreased after 2-min SS, without a concurrent decrease in the eccentric contraction torque [12]. In our study, the eccentric contraction torque did not decrease after 20-s SS, consistent with the previous study [12]. Therefore, the adverse effect of SS on eccentric contraction was minimal regardless of SS duration. However, since there are no previous studies comparing the difference of SS duration on the eccentric contraction torque, future studies are needed to investigate the effects of different SS durations on the eccentric contraction muscle strength.
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