Muscle Activation During Four Pilates Core Stability Exercises in Quadruped Position

Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. Arch Phys Med Rehabil 2010;91: 86-92. Objective: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position. Design: Repeated-measures descriptive study. Setting: A biomechanics laboratory at a university school of medicine. Participants: Healthy subjects (N=19; mean age +/- SD, 31 +/- 5y; mean weight +/- SD, 60 +/- 11 kg; mean height +/- SD, 166 +/- 9cm) experienced in Pilates routines. Interventions: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground. Main Outcome Measures: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction. Results: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk. Conclusions: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.

Effectiveness of core stability exercises and recovery myofascial release massage on fatigue in breast cancer survivors: a randomized controlled clinical trial.

The purpose of the present paper was to evaluate the effects of an 8-week multimodal program focused on core stability exercises and recovery massage with DVD support for a 6-month period in physical and psychological outcomes in breast cancer survivors. A randomized controlled clinical trial was performed. Seventy-eight (n = 78) breast cancer survivors were assigned to experimental (core stability exercises plus massage-myofascial release) and control (usual health care) groups. The intervention period was 8 weeks. Mood state, fatigue, trunk curl endurance, and leg strength were determined at baseline, after the last treatment session, and at 6 months of followup. Immediately after treatment and at 6 months, fatigue, mood state, trunk curl endurance, and leg strength exhibited greater improvement within the experimental group compared to placebo group. This paper showed that a multimodal program focused on core stability exercises and massage reduced fatigue, tension, depression, and improved vigor and muscle strength after intervention and 6 months after discharge.

Muscle Activation During Four Pilates Core Stability Exercises in Quadruped Position

Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. Arch Phys Med Rehabil 2010;91: 86-92.Objective: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position.Design: Repeated-measures descriptive study.Setting: A biomechanics laboratory at a university school of medicine.Participants: Healthy subjects (N=19; mean age +/- SD, 31 +/- 5y; mean weight +/- SD, 60 +/- 11 kg; mean height +/- SD, 166 +/- 9cm) experienced in Pilates routines.Interventions: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground.Main Outcome Measures: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction.Results: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk.Conclusions: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.

Core stability exercise in chronic low back pain

Exercise is commonly used in the management of chronic musculoskeletal conditions, including chronic low back pain (CLBP). The focus of exercise is varied and may include parameters ranging from strength and endurance training, to specific training of muscle coordination and control. The assumption underpinning these approaches is that improved neuromuscular function will restore or augment the control and support of the spine and pelvis. In a biomechanical model of CLBP, which assumes that pain recurrence is caused by repeated mechanical irritation of pain sensitive structures [1], it is proposed that this improved control and stability would reduce mechanical irritation and lead to pain relief [1]. Although this model provides explanation for the chronicity of LBP, perpetuation of pain is more complex, and contemporary neuroscience holds the view that chronic pain is mediated by a range of changes including both peripheral (eg, peripheral sensitization) and central neuroplastic changes [2]. Although this does not exclude the role of improved control of the lumbar spine and pelvis in management of CLBP, particularly when there is peripheral sensitization, it highlights the need to look beyond outdated simplistic models. One factor that this information highlights is that the refinement of control and coordination may be more important than simple strength and endurance training for the trunk muscles. The objective of this article is to discuss the rationale for core stability exercise in the management of CLBP, to consider critical factors for its implementation, and to review evidence for efficacy of the approach.

Validité de construit d’un test d’évaluation de la stabilité lombo-pelvienne, le soulèvement actif de la jambe tendue (SAJT) version objective

Introduction : L’évaluation clinique du contrôle neuromusculaire des muscles du tronc est criante en réhabilitation et en entraînement. L’objectif principal de cette étude a été d’évaluer la reproductibilité intra et inter-évaluateur d’un test clinique le soulèvement actif de la jambe tendue (SAJT) chez une population active et saine. Méthode : Chaque sujet (18 joueurs de tennis) a été testé à deux reprises par 2 physiothérapeutes avec le SAJT. Résultats : La reproductibilité intra-évaluateur s’est avérée élevée à très élevée (ICC = 0.81 à 0.93) tandis la reproductibilité inter-évaluateur s’est avérée cliniquement non viable. Conclusion : À notre connaissance, le SAJT est le premier test clinique reproductible évaluant le contrôle neuromusculaire du tronc avec des compensations musculaires et cinétiques chez des sujets actifs et sains. Une formation plus importante des évaluateurs aurait certainement amélioré la reproductibilité inter-évaluateur.

Influence of a preventive training program on lower limb kinematics and vertical jump height of male volleyball athletes

Objective: To examine the influence of a preventative training program (PTP) on sagittal plane kinematics during different landing tasks and vertical jump height (VJH) in males. Design: Six weeks prospective exercise intervention. Participants: Fifteen male volleyball athletes (13 ± 0.7 years, 1.70 ± 0.12 m, 60 ± 12 kg). Interventions: PTP consisting of plyometric, balance and core stability exercises three times per week for six weeks. Bilateral vertical jumps with double leg (DL) and single leg (SL) landings were performed to measure the effects of training. Main outcome measurements: Kinematics of the knee and hip before and after training and VJH attained during both tasks after training. The hypothesis was that the PTP would produce improvements in VJH, but would not generate great changes in biomechanical behavior. Results: The only change identified for the SL was the longest duration of landing, which represents the time spent from initial ground contact to maximum knee flexion, after training, while increased angular displacement of the knee was observed during DL. The training did not significantly alter the VJH in either the SL (difference: 2.7 cm) or the DL conditions (difference: 3.5 cm). Conclusions: Despite the PTP's effectiveness in inducing some changes in kinematics, the changes were specific for each task, which highlights the importance of the specificity and individuality in selecting prevention injury exercises. Despite the absence of significant increases in the VJH, the absolute differences after training showed increases corroborating with the findings of statistically powerful studies that compared the results with control groups. The results suggest that short-term PTPs in low risk young male volleyball athletes may enhance performance and induce changes in some kinematic parameters. © 2012 Elsevier Ltd.

Skadeförebyggande träningsmetoder mot hamstringsskador inom svensk herrelitfotboll i jämförelse med rekommenderad evidensbaserad forskning

Purpose The purpose of this study was to describe the evidence-based research recommendations on injury prevention methods against hamstring injuries among Swedish men's elite team in football. The research-based recommendations was then to be compared with the way Swedish elite football teams work to prevent hamstrings injuries. Method First a literature search of PubMed and SPORTDiscuss was made to find the most evidence-based training methods to hamstring injuries. Then an Internet questionnaire regarding injury prevention training methods against hamstring injuries was sent to all Swedish elite football teams. The answers off the questionnaire was then compared with the research that had the most evidence based training methods to hamstring injuries. Results Research shows that the method with the most evidence is eccentric strength training. Flexibility, static stretch and core stability training is research methods that can be used to prevent hamstrings injuries but these methods lack a large validated research basis. 8 of 32 (25 %) teams answered the questionnaire. All teams indicated that they were working with injury prevention methods but the methods varied from the eccentric strength training to periodization and flexibility training. 2 of 8 teams indicated that they worked with eccentric strength training that is recommended by science as the most evidence-based training method. Conclusion The study shows that the teams partly work after what the research recommends as the most evidence-based training methods against hamstring injuries. However, the study lacks validity and further research is needed before definitive conclusions can be drawn.

Neuromuscular adaptations in football athletes with prior history of hamstring strain injury

Background: Hamstring strain injuries (HSI) are one of the most common injuries in a wide variety of running-sports, resulting in a considerable loss of competition and training time. One of the most problematic consequences regarding HSI is the recurrence rate and its non-decrease over the past decades, despite increasing evidence. Recent studies also found several maladaptations post-HSI probably due to neuromuscular inhibition and it has been proposed that these adaptations post-injury may contribute as risk factors for the injury-reinjury cycle and high recurrence rates. Furthermore it has been recently proposed not to disregard the inter-relationship between these adaptations and risk-factors post-injury in order to better understand the mechanisms of this complex injury. Objective: To determine, analyze and correlate neuromuscular adaptations in amateur football players with prior history of HSI per comparison to uninjured athletes in similar conditions. Methodology: Every participant was subjected to isokinetic concentric (60 and 240deg.sec) and eccentric (30 and 120deg.sec¯¹) testing, and peak torque, angle of peak torque and hamstrings to quadriceps (H:Q) conventional ratios were measured, myoelectrical activity of Bicep Femoris (BF) and Medial Hamstrings (MH) were also measured during isokinetic eccentric testing at both velocities and muscle activation percentages were calculated at 30, 50 and 100ms after onset of contraction. Furthermore active and passive knee extension, knee joint position sense (JPS) test, triple-hop distance (THD) test and core stability (flexors and extensors endurance, right and left side bridge test) were used and correlated. Results: Seventeen players have participated in this study: 10 athletes with prior history of HSI, composing the Hamstring injury group (HG) and 7 athletes without prior severe injuries as control group (CG). We found statistical significant differences between HG injured and uninjured sides in the BF myoelectrical activity at almost all times in both velocities and between HG injured and CG non-dominant sides at 100ms in eccentric 120deg.sec¯¹ velocity (p<.05). We found no differences in MH activity. Regarding proprioception we found differences between the HG injured and uninjured sides (p=.027). We found no differences in the rest of used tests. However, significant correlation between myoelectrical activation at 100ms in 120deg.sec¯¹ testing and JPS with initial position at 90º (r-.372; p=0.031) was found, as well as between isokinetic H:Q ratio at 240deg.sec and THD score (r=-.345; p=.045). Conclusion: We found significant differences that support previous research regarding neuromuscular adaptations and BF inhibition post-HSI. Moreover, to our knowledge, this was the first study that found correlation between these adaptations, and may open a door to new perspectives and future studies.

Stability analysis of core-annular flow and neutral stability wave number

A general transition criterion is proposed in order to locate the core-annular flow pattern in horizontal and vertical oil-water flows. It is based on a rigorous one-dimensional two-fluid model of liquid-liquid two-phase flow and considers the existence of critical interfacial wave numbers related to a non-negligible interfacial tension term to which the linear stability theory still applies. The viscous laminar-laminar flow problem is fully resolved and turbulence effects on the stability are analyzed through experimentally obtained shape factors. The proposed general transition criterion includes in its formulation the inviscid Kelvin-Helmholtz`s discriminator. If a theoretical maximum wavelength is considered as a necessary condition for stability, a stability criterion in terms of the Eotvos number is achieved. Effects of interfacial tension, viscosity ratio, density difference, and shape factors on the stability of core-annular flow are analyzed in detail. The more complete modeling allowed for the analysis of the neutral-stability wave number and the results strongly suggest that the interfacial tension term plays an indispensable role in the correct prediction of the stable region of core-annular flow pattern. The incorporation of a theoretical minimum wavelength into the transition model produced significantly better results. The criterion predictions were compared with recent data from the literature and the agreement is encouraging. (C) 2007 American Institute of Chemical Engineers.

Thermodynamic stability of wild-type and mutant p53 core domain

Some 50% of human cancers are associated with mutations in the core domain of the tumor suppressor p53. Many mutations are thought just to destabilize the protein. To assess this and the possibility of rescue, we have set up a system to analyze the stability of the core domain and its mutants. The use of differential scanning calorimetry or spectroscopy to measure its melting temperature leads to irreversible denaturation and aggregation and so is useful as only a qualitative guide to stability. There are excellent two-state denaturation curves on the addition of urea that may be analyzed quantitatively. One Zn2+ ion remains tightly bound in the holo-form of p53 throughout the denaturation curve. The stability of wild type is 6.0 kcal (1 kcal = 4.18 kJ)/mol at 25°C and 9.8 kcal/mol at 10°C. The oncogenic mutants R175H, C242S, R248Q, R249S, and R273H are destabilized by 3.0, 2.9, 1.9, 1.9, and 0.4 kcal/mol, respectively. Under certain denaturing conditions, the wild-type domain forms an aggregate that is relatively highly fluorescent at 340 nm on excitation at 280 nm. The destabilized mutants give this fluorescence under milder denaturation conditions.

Expression and biochemical analysis of the entire HIV-2 gp41 ectodomain: determinants of stability map to N- and C-terminal sequences outside the 6-helix bundle core

The folding of HIV gp41 into a 6-helix bundle drives virus-cell membrane fusion. To examine the structural relationship between the 6-helix bundle core domain and other regions of gp41, we expressed in Escherichia coli, the entire ectodomain of HIV-2(ST) gp41 as a soluble, trimeric maltose-binding protein (MBP)/gp41 chimera. Limiting proteolysis indicated that the Cys-591-Cys-597 disulfide-bonded region is outside a core domain comprising two peptides, Thr-529-Trp-589 and Val-604-Ser-666. A biochemical examination of MBP/gp41 chimeras encompassing these core peptides; indicated that the N-terminal polar segment, 521-528, and C-terminal membrane-proximal segment, 658-666, cooperate in stabilizing the ectodomain. A functional interaction between sequences outside the gp41 core may contribute energy to membrane fusion. (C) 2004 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.

Stability and continuity of women's core beliefs and psychopathological symptoms from pregnancy to one year postpartum

Unhealthy core beliefs are theorized to be stable constructs throughout the life-span, but no research to date, outside of the context of clinical intervention, has addressed this claim over a period of greater than 6 weeks. This study explores the stability and continuity of core beliefs and psychopathological symptoms in a group of women over a major life event and for 1 year subsequently. Eighty-seven women completed measures assessing their core beliefs and psychopathological symptoms during pregnancy and at 6 and 12 months after giving birth. General maternal psychopathological symptoms significantly decreased across the group between pregnancy and 6 months postpartum, and between pregnancy and 1 year, but showed evidence of stability in the ranks of individuals across time. The majority of core beliefs remained both stable and continuous throughout this period of major transition. These findings generally support the theoretical contention that core beliefs are relatively stable and continuous self-constructs. Science+Business Media, LLC.