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Influence of back muscle fatigue on dynamic lumbar spine stability and coordination variability of the thorax-pelvis during repetitive flexion-extension movements

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JOURNAL OF BIOMECHANICS 2022年 133卷 110959-110959页

作者： Larson, Dennis J. Brown, Stephen H. M. Univ Guelph Dept Human Hlth & Nutr Sci Guelph ON Canada

Previous work has identified that individuals adopt different dynamic lumbar spine stability responses when experiencing back muscle fatigue, and that the neuromuscular system adjusts multi-joint coordination in response to fatigue. Therefore, this study was designed to determine whether distinct differences in coordination and coordination variability would be observed for those who stabilize, destabilize, or demonstrate no change in dynamic stability when their back muscles are fatigued. Thirty participants completed two repetitive trunk flexion-extension trials (Rested, Fatigued) during which lumbar flexion-extension dynamic stability, thoraxpelvis movement coordination, and coupling angle variability (CAV) were assessed. Dynamic stability was evaluated using maximum Lyapunov exponents (lambda max) with participants being allotted to stabilizer, destabilizer, or no change groups based on their stability response to fatigue. Each flexion-extension repetition was further segregated into two phases (flexion, extension) and vector coding analyses were implemented to determine thorax-pelvis coordination and CAV during each movement phase. Results demonstrated that when fatigued, -30% of individuals adopted more stable (lower lambda max) flexion-extension movements and greater CAV during the extension phase, -17% of individuals became less stable (higher lambda max) and exhibited decreased CAV during the extension phase, and the remaining -53% of individuals expressed no change in dynamic stability or CAV. Additionally, more in-phase coordination patterns were generally observed across all individuals when fatigued. Altogether, this study highlights the heterogeneous nature of lumbar spine movement behaviours within a healthy population in response to fatigue.

关键词： vector coding Trunk -pelvis coordination Local dynamic stability Lumbar spine Muscle Fatigue

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Trunk-pelvic coordination during unstable sitting with varying task demand: A methodological study

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JOURNAL OF BIOMECHANICS 2021年 118卷 110299-110299页

作者： Acasio, Julian C. Nussbaum, Maury A. Hendershot, Brad D. Walter Reed Natl Mil Med Ctr Dept Rehabil Res & Dev Sect Bethesda MD USA Henry M Jackson Fdn Adv Mil Med Inc Bethesda MD USA Virginia Tech Dept Ind & Syst Engn Blacksburg VA USA DoD VA Extrem Trauma & Amputat Ctr Excellence USA Res & Surveillance Div Ft Sam Houston TX USA Uniformed Serv Univ Hlth Sci Dept Rehabil Med Bethesda MD 20814 USA

Unstable sitting is used commonly to evaluate trunk postural control (TPC), typically via measures based on center-of-pressure (CoP) time series. However, these measures do not directly reflect underlying control/movement strategies. We quantified trunk-pelvis coordination during unstable sitting using vector coding (VC) and correlated such coordination with CoP-based outcomes across varying task demands. Thirteen uninjured individuals (11 male/2 female) sat on an unstable chair at four instability levels, in a random order, defined relative to the individual gravitational gradient (del G): 100, 75, 60, and 45%del G. VC assessed trunk-pelvic coordination, and coupling angles classified movements as: 1) anti-phase, 2) in-phase, 3) trunk-phase, or 4) pelvic-phase. With decreasing %del G (i.e., increasing instability), we found: increased anti-phase movement in the sagittal and frontal planes;decreased in-phase movement in the sagittal and frontal planes;and increased in-phase and pelvic-phase movement in the transverse plane. In the sagittal and frontal planes, we observed significant weak-to-moderate correlations between anti-phase and in-phase movements (0.288 < vertical bar rho vertical bar < 0.549). Correlations between CoP-based measures and pelvic-phase and trunk-phase movements were typically weak and/or non-significant (vertical bar rho vertical bar < 0.318). VC techniques discriminated between levels of instability during unstable sitting, identifying in-phase coordination (stiffening strategy) at lower instability levels and anti-phase coordination at higher instability levels. Compared to CoP-based measures, trunk coordination outcomes during unstable sitting provide measures of TPC that more directly quantify underlying movement strategies. These results can also serve as a baseline for future work investigating populations with impaired TPC (e.g., individuals with low back pain or limb loss). Published by Elsevier Ltd.

关键词： Postural control Low back pain vector coding Inter-segmental coordination Biomechanics

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Isolated Hamstrings Fatigue Alters Hip and Knee Joint Coordination During a Cutting Maneuver

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JOURNAL OF APPLIED BIOMECHANICS 2015年第2期31卷 102-110页

作者： Samaan, Michael A. Hoch, Matthew C. Ringleb, Stacie I. Bawab, Sebastian Weinhandl, Joshua T. Old Dominion Univ Dept Mech & Aerosp Engn Norfolk VA USA Old Dominion Univ Sch Phys Therapy & Athlet Training Norfolk VA USA Old Dominion Univ Dept Human Movement Sci Norfolk VA 23529 USA

The aim of this study was to determine the effects of hamstrings fatigue on lower extremity joint coordination variability during a sidestep cutting maneuver. Twenty female recreational athletes performed five successful trials of a sidestep cutting task pre- and postfatigue. Each participant completed an isolated hamstrings fatigue protocol consisting of isokinetic maximum effort knee flexion and passive extension contractions. vector coding was used to examine hip and knee joint couplings (consisting of various planar motions) during the impact and weight acceptance phases of the sidestep cut stance phase. Paired t tests were used to analyze differences of each phase as an effect of fatigue, where alpha was set a priori at .05. The hip rotation/knee rotation coupling exhibited a significant decrease in coordination variability as a function of fatigue in both the impact (P = .015) and weight acceptance phases (P = .043). Similarly, the hip adduction-abduction/knee rotation coupling exhibited a significant decrease in coordination variability in the weight acceptance phase (P = .038). Hamstrings fatigue significantly decreased coordination variability within specific lower extremity joint couplings that included knee rotation. Future studies should be conducted to determine if this decrease in coordination variability is related to lower extremity injury mechanisms.

关键词： variability vector coding knee kinematics

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Quantifying the hip-ankle synergy in short-term maximal cycling

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JOURNAL OF BIOMECHANICS 2022年 142卷 111268-111268页

作者： Burnie, Louise Barratt, Paul Davids, Keith Worsfold, Paul Wheat, Jon Northumbria Univ Fac Hlth & Life Sci Dept Sport Exercise & Rehabil Newcastle Upon Tyne England Sheffield Hallam Univ Sport & Phys Act Res Ctr Sheffield England English Inst Sport Biomech Manchester England BAE Syst Digital Manchester England Univ Chester Sport & Exercise Sci Chester England Sheffield Hallam Univ Coll Hlth Wellbeing & Life Sci Sheffield England

Simulation studies have demonstrated that the hip and ankle joints form a task-specific synergy during the downstroke in maximal cycling to enable the power produced by the hip extensor muscles to be transferred to the crank. The existence of the hip-ankle synergy has not been investigated experimentally. Therefore, we sought to apply a modified vector coding technique to quantify the strength of the hip-ankle moment synergy in the downstroke during short-term maximal cycling at a pedalling rate of 135 rpm. Twelve track sprint cyclists performed 3 x 4 s seated sprints at 135 rpm, interspersed with 2 x 4 s seated sprints at 60 rpm on an isokinetic ergometer. Data from the 60 rpm sprints were not analysed in this study. Joint moments were calculated via inverse dynamics, using pedal forces and limb kinematics. The hip-ankle moment synergy was quantified using a modified vector coding method. Results showed, for 28.8% of the downstroke the hip and ankle moments were in-phase, demonstrating the hip and ankle joints tend to work in synergy in the downstroke, providing some support findings from simulation studies of cycling. At a pedalling rate of 135 rpm the hip-phase was most frequent (42.5%) significantly differing from the in-(P = 0.044), anti-(P < 0.001), and ankle-phases (P = 0.004), demonstrating hip-dominant action. We believe this method shows promise to answer research questions on the relative strength of the hip-ankle synergy between different cycling conditions (e.g., power output and pedalling rates).

关键词： Joint moments Movement coordination Sprint cycling vector coding

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Lower limb inter-joint coordination in individuals with osteoarthritis before and after a total knee arthroplasty

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CLINICAL BIOMECHANICS 2022年 100卷 105806-105806页

作者： Pelegrinelli, Alexandre R. M. Kowalski, Erik Ryan, Nicholas S. Moura, Felipe A. Lamontagne, Mario Univ Estadual Londrina Lab Appl Biomech Londrina Brazil Univ Ottawa Human Movement Biomech Lab Ottawa ON Canada Univ Ottawa Human Movement Biomech Lab Lab Biomecan Mouvement Humain 200 Lees Ave E 020 Ottawa ON K1N 6N5 Canada

Background: Total knee arthroplasty is the most common treatment for severe knee osteoarthritis. Coordination and variability analyses are effective measures of the injury stage or rehabilitation process. This study compared the inter-joint coordination before and after arthroplasty, compared to ***: Twenty-seven patients were evaluated before and 12 months after surgery, compared to 27 controls. Coordination and variability in the sagittal plane between the hip-knee and knee-ankle were calculated using vector coding and circular statistics. Coordination was categorized as in-phase, anti-phase, or distal or proximal joint-phase. The gait cycle was divided into sub-phases for the coordination, variability, and range of motion ***: Coordination and range of motion differed significantly between the patient groups and controls, while small differences between pre-and post-operative groups were also detected. The hip-knee showed a reduced in phase frequency in the patient group compared to control during stance, particularly mid-stance: pre-operative 24.3% +/- 33.9, post-operative 29.5 +/- 29.7, and controls 70.7 +/- 17.0. This difference was compensated for by increasing proximal-phase (hip) frequency in the patient groups. For knee-ankle coordination, the patient groups showed higher distal-phase (ankle) frequency during the early and mid-stance. Coordination variability was higher post-operatively during swing and terminal swing phases, compared to ***: The results indicated reduced degrees of freedom for the knee during stance phase with a reduced capacity to move the knee and hip in opposing directions before and one year after surgery. The patient group after the surgery increased knee range of motion and coordination compared to pre-operative during swing phase.

关键词： Kinematics Gait Coordination vector coding Variability Total Knee Arthroplasty Osteoarthritis

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Comparison of two coupling methods regarding coupling patterns, sensitivity to footwear and potential future injury applications

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JOURNAL OF BIOMECHANICS 2021年 125卷 110591-110591页

作者： Behling, Anja-Verena Kloock, Lena Nigg, Benno M. Univ Calgary Schulich Sch Engn Biomed Engn Calgary AB Canada Univ Calgary Fac Kinesiol Human Performance Lab Calgary AB Canada Univ Queensland Sch Human Movement & Nutr Sci Brisbane Qld Australia Justus Liebig Univ Fac Psychol & Sports Sci Inst Sports Sci Giessen Germany

Researchers have quantified the effect of footwear conditions on movement patterns and injury risk for runners using discrete kinematic variables and/or relative coupling variables. Coupling is typically assessed using the transfer coefficient (TC) or the vector coding (VC) approach. However, a thorough comparison of both methods regarding their interpretation, sensitivity to testing conditions and information regarding coupling strength as one overall coupling score is missing. This study aimed to compare both methods regarding a) their coupling patterns, b) their sensitivity to foot-wear conditions and c) to discuss both coupling approaches regarding an overall coupling score. 3D motion capture data was collected of 10 males running on a treadmill with and without shoes. Rearfoot frontal and tibia transverse plane motion was analyzed. Discrete kinematic variables and relative coupling variables were calculated via the TC and VC approach for the landing and push-off phase. A novel variable, the coupling score, was developed and calculated using both coupling methods. Coupling variables calculated with both methods showed differences in coupling patterns, especially for the landing phase (TC approximate to 0.5/in-phase towards rearfoot-phase, VC approximate to 300 degrees/anti-phase). VC offers further details, such as coupling frequencies, compared to the TC. Moreover, both methods were unable to distinguish between footwear conditions regarding their coupling patterns or coupling scores. Strong correlations (r <= 0.7, p < 0.0125) between coupling scores assessed with either method suggest that both methods contain similar information regarding coupling strength. The coupling score represents a first attempt to quantify a weighted coupling pattern quantitatively. Future studies have to validate whether the coupling score might be linked to injury risks.

关键词： Movement transfer Coordination Lower extremity injuries Dynamic systems vector coding

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Lower extremity inter-joint coupling angles and variability during gait in pediatric hypermobility spectrum disorder

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JOURNAL OF BIOMECHANICS 2024年 170卷 112151-112151页

作者： Jeong, Hyo-Jung Tarima, Sergey Nguyen, Anthony Qashqai, Anahita Muriello, Michael Basel, Donald Slavens, Brooke A. Marquette Univ Orthopaed & Rehabil Engn Ctr Milwaukee WI 53233 USA Univ Wisconsin Milwaukee Dept Rehabil Sci & Technol Milwaukee WI 53211 USA Washington Univ Sch Med St Louis Program Phys Therapy St Louis MO 63130 USA Med Coll Wisconsin Inst Hlth & Equ Div Biostat Milwaukee WI USA Univ Wisconsin Milwaukee Dept Mech Engn Milwaukee WI USA Med Coll Wisconsin Div Genet Dept Pediat Milwaukee WI USA

Complex musculoskeletal complications in children with hypermobility spectrum disorder (HSD) include pain, proprioception deficits, and joint instability, which may result in movement dysfunction during walking. However, no studies have explored the inter-joint coordination deficits in children with HSD. The purpose of this study was to determine the lower extremity inter-joint coupling angles, patterns, and variability during walking in children with HSD compared to children without HSD (non-HSD). Ankle, knee, and hip kinematics during the stance phase of walking in 18 children with HSD and 18 children without HSD were measured using threedimensional motion analysis. Coupling angles, patterns, and variability of hip-knee, hip-ankle, and knee-ankle were quantified in the sagittal, frontal, and transverse planes using vector coding techniques. Statistical modeling of coupling angles on sine and cosine scales and bootstrapped standard errors were used to compare coupling angles between HSD and non-HSD groups. Permutational multivariate analysis of variance and statistical non-parametric mapping two-sample t-tests were used to compare the coupling patterns and variability between HSD and non-HSD groups, respectively. Our results indicated that coupling angles, patterns, and variability were not significantly different between the groups. These findings suggest that lower extremity inter- joint coordination and its variability during walking might not be a promising area for further research or intervention in children with HSD. Further research could use other biomechanical methods to investigate coordination deficits in pediatric patients with HSD, and how aging and disease progression are associated with coordination deficits in individuals with HSD.

关键词： Hypermobility Gait vector coding Kinematics Coordination

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Individuals with recurrent low back pain exhibit further altered frontal plane trunk control in remission than when in pain

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CLINICAL BIOMECHANICS 2021年 87卷 105391-105391页

作者： Shih, Hai-Jung Steffi Van Dillen, Linda R. Kutch, Jason J. Kulig, Kornelia Univ Southern California Div Biokinesiol & Phys Therapy 1540 E Alcazar StCHP 155 Los Angeles CA 90033 USA Washington Univ Sch Med St Louis Program Phys Therapy St Louis MO USA Washington Univ Sch Med St Louis Dept Orthopaed Surg St Louis MO USA

Background: Movement alterations due to low back pain (LBP) could lead to long-term adverse consequences if they do not resolve after symptoms subside. This study aims to determine if altered trunk control associated with recurrent low back pain persists beyond symptom duration. Methods: Twenty young adults with recurrent LBP were tested once during an LBP episode and once in symptom remission, and twenty matched back-healthy participants served as controls. Participants walked on a treadmill with five prescribed step widths (0.33, 0.67, 1, 1.33, 1.67 x preferred step width). Motion capture and surface electromyography were used to record trunk kinematics and muscle activation. Thorax-pelvis coordination was calculated using vector coding, and longissimus activation and co-activation were analyzed. Findings: Young adults with recurrent LBP exhibited a "looser" trunk control strategy in the frontal plane during gait that was persistent regardless of pain status across multiple step widths compared to controls. The looser trunk control was demonstrated by a greater pelvis-only, less thorax-only coordination pattern, and decreased bilateral longissimus co-activation in individuals with recurrent LBP compared to controls. The looser trunk control strategy was further amplified when individuals were in symptom remission and exhibited greater trunk excursion and reduced in-phase coordination in the frontal plane. Interpretation: The amplification of aberrant movement during symptom remission may suggest that movement patterns or anatomical factors existing prior to the tested painful episode underlie altered trunk control in individuals with recurrent LBP. The symptom remission period of recurrent LBP may be a critical window into clinical evaluation and treatment.

关键词： Gait Muscle activity Trunk coordination vector coding Low back pain

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Intra-task variability of trunk coordination during a rate-controlled bipedal dance jump

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JOURNAL OF SPORTS SCIENCES 2012年第2期30卷 139-147页

作者： Smith, Jo Armour Siemienski, Adam Popovich, John M., Jr. Kulig, Kornelia Univ So Calif Div Biokinesiol & Phys Therapy Los Angeles CA 90089 USA Univ Sch Phys Educ Dept Biomech Wroclaw Poland

In this study, we investigated trunk coordination during rate-controlled bipedal vertical dance jumps. The aims of the study were to investigate the pattern of coordination and the magnitude of coordination variability within jump phases and relative to phase-defining events during the jump. Lumbar and thoracic kinematics were collected from seven dancers during a series of jumps at 95 beats per minute. The vector coding technique was used to quantify the pattern and variability of trunk coordination. Coordination was predominantly anti-phase during propulsion and landing. Mean coordination variability peaked just before the landing phase and at the transition from landing to propulsion phases, and was lowest during the propulsion phase just before toe-off. The results indicate that peaks in variability could be explained by task and phase-specific biomechanical demands.

关键词： Trunk coordination vector coding jumping

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Segment coupling and coordination variability analyses of the roundhouse kick in taekwondo relative to the initial stance position

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JOURNAL OF SPORTS SCIENCES 2016年第18期34卷 1766-1773页

作者： Estevan, Isaac Silvernail, Julia Freedman Jandacka, Daniel Falco, Coral Univ Valencia Dept Teaching Mus Plast & Corporal Express Avda Tarongers S-N Valencia 46022 Spain Univ Nevada Las Vegas Dept Kinesiol & Nutr Sci Las Vegas NV USA Univ Ostrava Human Motion Diagnost Ctr Ostrava Czech Republic Univ Bergen Dept Hlth Promot & Dev Bergen Norway

The initial stance position (ISP) has been observed as a factor affecting the execution technique during taekwondo kicks. In the present study, authors aimed to analyse a roundhouse kick to the chest by measuring movement coordination and the variability of coordination and comparing this across the different ISP (0 degrees, 45 degrees and 90 degrees). Eight experienced taekwondo athletes performed consecutive kicking trials in random order from every of the three relative positions. The execution was divided into three phases (stance, first swing and second swing phase). A motion capture system was used to measure athletes' angular displacement of pelvis and thigh. A modified vector coding technique was used to quantify the coordination of the segments which contributed to the overall movement. The variability of this coordination (CV) for each ISP was also calculated. Comparative analysis showed that during the stance phase in the transverse plane, athletes coordinated movement of the trunk and thigh with a higher frequency of in-phase and lower frequency of exclusive thigh rotation in the 0 degrees stance than the 90 degrees stance position (P<0.05). CV was also influenced by the different ISP. During the first swing and the majority of the second swing phase, predominant in-phase coordination of the pelvis and thigh was observed. Including exercises that require in-phase movement could not only help athletes to acquire coordination stability but also efficiency. The existence of a constraint such as ISP implies an increase of the variability when the athletes have to kick from ISP they are not used to adopt (i.e., 0 degrees and 90 degrees ISP) as an evidence of adaptability in the athletes' execution technique.

关键词： Martial arts biomechanics vector coding variability

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