Muscle activation patterns of selected lower extremity muscles during stepping and cutting tasks (original) (raw)
Related papers
Does lower limb neuromuscular control differ during side-step and split-step cutting manoeuvres?
Journal of Science and Medicine in Sport, 2010
During side-step cutting, all the monitored muscles were recruited simultaneously reflecting co-contraction. Conversely, during split-step cutting, rectus femoris was initially recruited, followed by synchronous vastii and medial hamstrings onset and then lateral hamstring muscle onset. Although there were subtle differences in onset, the hamstrings ceased activity earlier than the quadriceps muscles in both cutting manoeuvres. Paired ttests indicated that vastus medialis displayed a significantly (p < 0.02) earlier onset in the side-step compared to the split-step and rectus femoris displayed significantly (p = 0.05) longer burst duration in the split-step compared to the side-step. Whether these altered neuromuscular patterns are protective to the knee during split-step cutting manoeuvres, perhaps due to reduced anterior drawer, warrants further investigation. However, should the neuromuscular patterns observed in the split-step protect the ACL from injury, research should also investigate whether split-step cutting manoeuvres display any performance detriment compared to side-step cutting manoeuvres.
Muscle Activation Strategies at the Knee during Running and Cutting Maneuvers
Medicine and science in sports …, 2003
Creating, validating and applying personalised neuromusculoskeletal computational models View project Pathophysiology and kinematics of thumb carpometacarpal osteoarthritis View project . Purpose: The purpose of this article was to investigate the activation patterns of muscles surrounding the knee during preplanned (PP) and unanticipated (UN) running and cutting tasks, with respect to the external moments applied to the joint. It was hypothesized that activation strategies during PP tasks would correspond to the magnitude and direction of the external loads applied to the knee joint, and the muscle activation patterns would differ between PP and UN tasks. Methods: Eleven healthy male subjects performed a series of running and cutting tasks under PP and UN conditions. Activation from 10 knee muscles were determined using full-wave rectified, filtered, and normalized EMG calculated during a precontact phase and two epochs across the stance phase. Knee joint flexor and extensor muscle group ratios indicated the level of co-contraction. Individual muscles were also grouped into medial/lateral and internal/external rotation muscle groups, based upon their ability to counter externally applied varus/valgus and internal/external rotation joint loads, respectively. Results: Selective activation of medial/lateral and internal/external rotation muscles and co-contraction of flexors and extensors were used to stabilize the joint under PP conditions, whereas generalized co-contraction strategies were employed during the UN condition. Net muscle activation during the UN sidestepping tasks increased by 10 -20%, compared with an approximately 100% increase in applied varus/valgus and internal/ external rotation joint moments. Conclusion: In PP conditions, activation patterns appear to be selected to support the external loads experienced at the knee, e.g., medial muscles activated to resist applied valgus moments. Under UN conditions, there was no selective activation of muscles to counter the external knee load, with generalized co-contraction being the activation pattern adopted. These findings have implications for the etiology of noncontact knee ligament injuries.
The Influence of Knee and Ankle Bracing on Lower Extremity Kinematics During a Cutting Maneuver
Medicine & Science in Sports & Exercise, 2007
Context: Functional knee braces (FKB) are used prophylactically and in rehabilitation to aide in the functional stability of the knee joint. Objective: To determine if alterations in sagittal plane lower extremity kinematics remain evident throughout a one hour period in healthy individuals. Design: 2X5 repeated measures design. Setting: Biomechanics Laboratory. Subjects: Twenty subjects (14 male and 6 female, mean age 26.5±7 yrs; height 172.4±13 cm; weight 78.6±9 kg), separated into braced (B) and no brace (NB) groups. Intervention: A one-hour exercise program divided into three 20 minute increments. Main Outcome Measures: Synchronized three-dimensional kinematic data were collected at 20-minute increments to assess the effect of the FKB on select lower extremity joint kinematics. Results: Hip, knee and ankle joint position were not significantly affected by time (exercise). However significant decreases in hip (p = .05) and knee flexion (p < .05) were noted in the B group compared to the NB group regardless of time while ankle joint position was unaffected. Conclusions: Hip and knee flexion angles were reduced in the B group compared to the NB group, while ankle joint position was not affected. Wearing a knee brace appears to not only influence knee joint position but also hip joint position. It is possible that repetitive changes to hip joint kinematics may be detrimental to hip and low back function and thus lead to injury.
Gait & Posture, 2006
Background: Frontal plane trunk and lower extremity adjustments during unanticipated tasks are hypothesized to influence hip and knee neuromuscular control, and therefore, contribute to anterior cruciate ligament (ACL) injury risk. The aims of this study were to examine frontal plane trunk/hip kinematics and hip and knee moments (measures of neuromuscular control) during unanticipated straight and side step cut tasks. Methods: Kinematic and kinetic variables were collected while subjects performed two anticipated tasks, including walking straight (ST) and side step cutting (SS), and two unanticipated tasks (STU and SSU). Foot placement, thorax-pelvis-hip kinematic variables and hip and knee moments were calculated over the first 30% of stance. Findings: Hip abduction angles and knee moments were significantly affected by task and anticipation. Hip abduction angles decreased, by 4.0-7.68, when comparing the SSU task to the ST, STU and SS tasks. The hip abduction angles were associated with foot placement and lateral trunk orientation. Interpretation: Hip abduction angles and foot placement, not lateral trunk flexion influence trunk orientation. Anticipation influences hip and knee neuromuscular control and therefore may guide the development of ACL prevention strategies.
The Effect of Technique Change on Knee Loads During Sidestep Cutting
Medicine & Science …, 2007
Purpose: To identify the effect of modifying sidestep cutting technique on knee loads and predict what impact such change would have on the risk of noncontact anterior cruciate ligament injury. Methods: A force platform and motion-analysis system were used to record ground-reaction forces and track the trajectories of markers on 15 healthy males performing sidestep cutting tasks using their normal technique and nine different imposed techniques. A kinematic and inverse dynamic model was used to calculate the three-dimensional knee postures and moments. Results: The imposed techniques of foot wide and torso leaning in the opposite direction to the cut resulted in increased peak valgus moments experienced in weight acceptance. Higher peak internal rotation moments were found for the foot wide and torso rotation in the opposite direction to the cut techniques. The foot rotated in technique resulted in lower mean flexion/extension moments, whereas the foot wide condition resulted in higher mean flexion/extension moments. The flexed knee, torso rotated in the opposite direction to the cut and torso leaning in the same direction as the cut techniques had significantly more knee flexion at heel strike. Conclusion: Sidestep cutting technique had a significant effect on loads experienced at the knee. The techniques that produced higher valgus and internal rotation moments at the knee, such as foot wide, torso leaning in the opposite direction to the cut and torso rotating in the opposite direction to the cut, may place an athlete at higher risk of injury because these knee loads have been shown to increase the strain on the anterior cruciate ligament. Training athletes to avoid such body positions may result in a reduced risk of noncontact anterior cruciate ligament injures.
Knee moments during run-to-cut maneuvers are associated with lateral trunk positioning
Non-contact anterior cruciate ligament (ACL) injuries account for approximately 70% of ACL ruptures and often occur during a sudden change in direction or pivot. Decreased neuromuscular control of the trunk in a controlled perturbation task has previously been associated with ACL injury incidence, while knee abduction moments and tibial internal rotation moments have been associated with ACL strain and ACL injury incidence. In this study, the association between movement of the trunk during a run-to-cut maneuver and loading of the knee during the same activity was investigated. External knee moments and trunk angles were quantified during a run-to-cut maneuver for 29 individuals. The trunk angles examined were outside tilt (frontal plane angle of the torso from vertical), angle between the ground reaction force (GRF) and the torso in the plane containing the GRF and shoulders (torso-GRF_shoulders); and angle between GRF and torso in the plane containing the GRF and pelvis (torso-GRF_pelvis). Significant positive associations were found between torso angles and peak knee abduction moments (outside tilt, p ¼0.002; and torso-GRF_shoulders, p ¼0.036) while a significant negative association was found between peak tibial internal rotation moment and outside tilt (p ¼ 0.021). Because the peaks of these moments occur at different times and minimal axial rotation moment is observed at peak knee abduction moment (À 0.297 0.46%BW*ht), the positive association between peak knee abduction moment and torso lean suggests that increasing torso lean may increase ACL load and risk of injury.
2014
The purpose of this study was to determine differences in knee joint loading of athletes performing the side-step cutting manoeuvres under two different conditions (fatigued vs. non-fatigued). Lower limb joint kinematics and kinetics of 12 inter-varsity soccer players (6 males and 6 females) performing side-step tasks in two conditions were quantified using 10 optical cameras and Kistler™ force-platform. Fatigue conditions elicited significantly higher sagittal knee joint loadings (Mext, FPeak_GRF_Z, FPeak_AP_GRF and ?°GRF_Z_IC) then non-fatigued suggesting that athletes when fatigued adopted different strategies to compensate the changes to their environment.
Reliability of Knee Joint Measures in a Cutting Movement
2012
Eight female soccer athletes performed six horizontal jump and cut maneuvers onto two AMTI force platforms. 3D kinematic analysis of 22 marked body landmarks coupled with ground reaction forces (GRF) were analyzed for peak knee flexion and valgus angles, GRF, and knee abduction moments with repeated measures ANOVA. Analysis indicated no significant difference between trials (p > 0.05). Average measures Intraclass Correlation Coefficients resulted in values of r = 0.71 to 0.99. Results indicate good reliability for flexion angles and excellent reliability for valgus angles, GRF, and knee abduction moments.