The time course of in vivo recovery of transverse strain in high-stress tendons following exercise

Objective To evaluate the time course of the recovery of transverse strain in the Achilles and patellar tendon following a bout of resistance exercise. Methods Seventeen healthy adults underwent sonographic examination of the right patellar (n=9) and Achilles (n=8) tendons immediately prior to and following 90 repetitions of weight-bearing quadriceps and gastrocnemius-resistance exercise performed against an effective resistance of 175% and 250% body weight, respectively. Sagittal tendon thickness was determined 20 mm from the enthesis and transverse strain, as defined by the stretch ratio, was repeatedly monitored over a 24 h recovery period. Results Resistance exercise resulted in an immediate decrease in Achilles (t7=10.6, p<0.01) and patellar (t8=8.9, p<0.01) tendon thickness, resulting in an average transverse stretch ratio of 0.86±0.04 and 0.82±0.05, which was not significantly different between tendons. The magnitude of the immediate transverse strain response, however, was reduced with advancing age (r=0.63, p<0.01). Recovery in transverse strain was prolonged compared with the duration of loading and exponential in nature. The average primary recovery time was not significantly different between the Achilles (6.5±3.2 h) and patellar (7.1±3.2 h) tendons. Body weight accounted for 62% and 64% of the variation in recovery time, respectively. Conclusions Despite structural and biochemical differences between the Achilles and patellar tendon, the mechanisms underlying transverse creep recovery in vivo appear similar and are highly time dependent. These novel findings have important implications concerning the time required for the mechanical recovery of high-stress tendons following an acute bout of exercise.

How much is enough? The effect of exercise repetition on the force frequency characteristics of eccentric exercise used for tendinopathy rehabilitation

Introduction: Eccentric exercise (EE) is a commonly used treatment for Achilles tendinopathy. While vibrations in the 8–12 Hz frequency range generated during eccentric muscle actions have been put forward as a potential mechanism for the beneficial effect of EE, optimal loading parameters required to expedite recovery are currently unknown. Alfredson's original protocol employed 90 repetitions of eccentric loading, however abbreviated protocols consisting of fewer repetitions (typically 45) have been developed, albeit with less beneficial effect. Given that 8–12 Hz vibrations generated during isometric muscle actions have been previously shown to increase with fatigue, this research evaluated the effect of exercise repetition on motor output vibrations generated during EE by investigating the frequency characteristics of ground reaction force (GRF) recorded throughout the 90 repetitions of Alfredson's protocol. Methods: Nine healthy adult males performed six sets (15 repetitions per set) of eccentric ankle exercise. GRF was recorded at a frequency of 1000 Hz throughout the exercise protocol. The frequency power spectrum of the resultant GRF was calculated and normalized to total power. Relative spectral power was summed over 1 Hz widows within the frequency rage 7.5–11.5 Hz. The effect of each additional exercise set (15 repetitions) on the relative power within each widow was investigated using a general linear modelling approach. Results: The magnitude of peak relative power within the 7.5–11.5 Hz bandwidth increased across the six exercise sets from 0.03 in exercise set one to 0.12 in exercise set six (P < 0.05). Following the 4th set of exercise the frequency at which peak relative power occurred shifted from 9 to 10 Hz. Discussion: This study has demonstrated that successive repetitions of eccentric loading over six exercise sets results in an increase in the amplitude of motor output vibrations in the 7.5–11.5 Hz bandwidth, with an increase in the frequency of these vibrations occurring after the 4th set (60th repetition). These findings are consistent with findings from previous studies of muscle fatigue. Assuming that the magnitude and frequency of these vibrations represent important stimuli for tendon remodelling as hypothesized within the literature, the findings of this study question the role of abbreviated EE protocols and raise the question; can EE protocols for tendinopathy be optimized by performing eccentric loading to fatigue?

The acute transverse strain response of the patellar tendon to quadriceps exercise

Introduction: The human patellar tendon is highly adaptive to changes in habitual loading but little is known about its acute mechanical response to exercise. This research evaluated the immediate transverse strain response of the patellar tendon to a bout of resistive quadriceps exercise. Methods: Twelve healthy adult males (mean age 34.0+/-12.1 years, height 1.75+/-0.09 m and weight 76.7+/-12.3 kg) free of knee pain participated in the research. A 10-5 MHz linear-array transducer was used to acquire standardised sagittal sonograms of the right patellar tendon immediately prior to and following 90 repetitions of a double-leg parallel-squat exercise performed against a resistance of 175% bodyweight. Tendon thickness was determined 20-mm distal to the pole of the patellar and transverse Hencky strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness and expressed as a percentage. Measures of tendon echotexture (echogenicity and entropy) were also calculated from subsequent gray-scale profiles. Results: Quadriceps exercise resulted in an immediate decrease in patellar tendon thickness (P<.05), equating to a transverse strain of -22.5+/-3.4%, and was accompanied by increased tendon echogenicity (P<.05) and decreased entropy (P<.05). The transverse strain response of the patellar tendon was significantly correlated with both tendon echogenicity (r = -0.58, P<.05) and entropy following exercise (r=0.73, P<.05), while older age was associated with greater entropy of the patellar tendon prior to exercise (r=0.79, P<.05) and a reduced transverse strain response (r=0.61, P<.05) following exercise. Conclusions: This study is the first to show that quadriceps exercise invokes structural alignment and fluid movement within the matrix that are manifest by changes in echotexture and transverse strain in the patellar tendon., (C)2012The American College of Sports Medicine

Overweight and obesity alters the cumulative transverse strain in the Achilles tendon immediately following exercise

This research evaluated the effect of obesity on the acute cumulative transverse strain of the Achilles tendon in response to exercise. Twenty healthy adult males were categorized into ‘low normal-weight’ (BMI <23 kg m−2) and ‘overweight’ (BMI >27.5 kg m−2) groups based on intermediate cut-off points recommended by the World Health Organization. Longitudinal sonograms of the right Achilles tendon were acquired immediately prior and following weight-bearing ankle exercises. Achilles tendon thickness was measured 20-mm proximal to the calcaneal insertion and transverse tendon strain was calculated as the natural log of the ratio of post- to pre-exercise tendon thickness. The Achilles tendon was thicker in the overweight group both prior to (t18 = −2.91, P = 0.009) and following (t18 = −4.87, P < 0.001) exercise. The acute transverse strain response of the Achilles tendon in the overweight group (−10.7 ± 2.5%), however, was almost half that of the ‘low normal-weight’ (−19.5 ± 7.4%) group (t18 = −3.56, P = 0.004). These findings suggest that obesity is associated with structural changes in tendon that impairs intra-tendinous fluid movement in response to load and provides new insights into the link between tendon pathology and overweight and obesity.

Achilles tendinopathy modulates force frequency characteristics of eccentric exercise

Introduction Previous research has demonstrated that ground reaction force (GRF) recorded during eccentric ankle exercise is characterised by greater power in the 8-12Hz bandwidth when compared to that recorded during concentric ankle exercise. Subsequently, it was suggested that vibrations in this bandwidth may underpin the beneficial effect of eccentric loading in tendon repair. However, this observation has been made only in individuals without Achilles tendinopathy. This research compared the force frequency characteristics of eccentric and concentric exercises in individuals with and without Achilles tendinopathy., Methods Eleven male adults with unilateral mid-portion Achilles tendinopathy and nine control male adults without tendinopathy participated in the research. Kinematics and GRF were recorded while the participants performed a common eccentric rehabilitation exercise protocol and a concentric equivalent. Ankle joint kinematics and the frequency power spectrum of the resultant GRF were calculated. Results Eccentric exercise was characterised by a significantly greater proportion of spectral power between 4.5 and 11.5Hz when compared to concentric exercise. There were no significant differences between limbs in the force frequency characteristics of concentric exercise. Eccentric exercise, in contrast, was defined by a shift in the power spectrum of the symptomatic limb, resulting in a second spectral peak at 9Hz, rather than 10Hz in the control limb. Conclusions Compared to healthy tendon, Achilles tendinopathy was characterised by lower frequency vibrations during eccentric rehabilitation exercises. This finding may be associated with changes in neuromuscular activation and tendon stiffness which have been shown to occur with tendinopathy and provides a possible rationale for the previous observation of a different biochemical response to eccentric exercise in healthy and injured Achilles tendons., (C)2012The American College of Sports Medicine

Transcriptome analysis of neutrophils after endurance exercise reveals novel signaling mechanisms in the immune response to physiological stress

Neutrophils serve as an intriguing model for the study of innate immune cellular activity induced by physiological stress. We measured changes in the transcriptome of circulating neutrophils following an experimental exercise trial (EXTRI) consisting of 1 h of intense cycling immediately followed by 1 h of intense running. Blood samples were taken at baseline, 3 h, 48 h, and 96 h post-EXTRI from eight healthy, endurance-trained, male subjects. RNA was extracted from isolated neutrophils. Differential gene expression was evaluated using Illumina microarrays and validated with quantitative PCR. Gene set enrichment analysis identified enriched molecular signatures chosen from the Molecular Signatures Database. Blood concentrations of muscle damage indexes, neutrophils, interleukin (IL)-6 and IL-10 were increased (P < 0.05) 3 h post-EXTRI. Upregulated groups of functionally related genes 3 h post-EXTRI included gene sets associated with the recognition of tissue damage, the IL-1 receptor, and Toll-like receptor (TLR) pathways (familywise error rate, P value < 0.05). The core enrichment for these pathways included TLRs, low-affinity immunoglobulin receptors, S100 calcium binding protein A12, and negative regulators of innate immunity, e.g., IL-1 receptor antagonist, and IL-1 receptor associated kinase-3. Plasma myoglobin changes correlated with neutrophil TLR4 gene expression (r = 0.74; P < 0.05). Neutrophils had returned to their nonactivated state 48 h post-EXTRI, indicating that their initial proinflammatory response was transient and rapidly counterregulated. This study provides novel insight into the signaling mechanisms underlying the neutrophil responses to endurance exercise, suggesting that their transcriptional activity was particularly induced by damage-associated molecule patterns, hypothetically originating from the leakage of muscle components into the circulation.

“Freer than we Feel” : Applying the Critical Dimension of Consciousness to Children’s Multimodal Encoding

Reports of children and teachers taking transformative social action in schools are becoming rare. This session illustrates how teachers, while feeling the weight of accountability testing in schools, are active agents who can re-imagine literacy pedagogy to change elements of their community. It reports the critical dimensions of a movie-making unit with Year 5 students within a school reform project. The students filmed interviews with people in the local shops to gather lay-knowledge and experiences of the community. The short documentaries challenged stereotypes about what it is like to live in Logan, and critically identified potential improvements to public spaces in the local community. A student panel presented these multimodal texts at a national conference of social activists and community leaders. The report does not valorize or privilege local or lay knowledge over dominant knowledge, but argues that prescribed curriculum should not hinder the capacity for critical consciousness.

The kineikonic mode : a multimodal analysis of students’ claymation movies

Globalised communication in society today is characterised by multimodal forms of meaning making in the context of increased cultural and linguistic diversity. This research paper responds to these imperatives, applying Halliday's (1978, 1994) categories of systemic functional linguistics - representational or ideational, interactive or interpersonal, and compositional or textual meanings. Following the work of Kress (2000), van Leeuwen (Kress and van Leeuwen, 1996), and Jewitt (2006), multimodal semiotic analysis is applied to claymation movies that were collaboratively designed by Year 6 students. The significance of this analysis is the metalanguage for textual work in the kineikonic mode - moving images.

Alternative models of cardiac rehabilitation : a systematic review

The traditional hospital-based model of cardiac rehabilitation faces substantial challenges, such as cost and accessibility. These challenges have led to the development of alternative models of cardiac rehabilitation in recent years. The aim of this study was to identify and critique evidence for the effectiveness of these alternative models. A total of 22 databases were searched to identify quantitative studies or systematic reviews of quantitative studies regarding the effectiveness of alternative models of cardiac rehabilitation. Included studies were appraised using a Critical Appraisal Skills Programme tool and the National Health and Medical Research Council's designations for Level of Evidence. The 83 included articles described interventions in the following broad categories of alternative models of care: multifactorial individualized telehealth, internet based, telehealth focused on exercise, telehealth focused on recovery, community- or home-based, and complementary therapies. Multifactorial individualized telehealth and community- or home-based cardiac rehabilitation are effective alternative models of cardiac rehabilitation, as they have produced similar reductions in cardiovascular disease risk factors compared with hospital-based programmes. While further research is required to address the paucity of data available regarding the effectiveness of alternative models of cardiac rehabilitation in rural, remote, and culturally and linguistically diverse populations, our review indicates there is no need to rely on hospital-based strategies alone to deliver effective cardiac rehabilitation. Local healthcare systems should strive to integrate alternative models of cardiac rehabilitation, such as brief telehealth interventions tailored to individual's risk factor profiles as well as community- or home-based programmes, in order to ensure there are choices available for patients that best fit their needs, risk factor profile, and preferences.

A novel device using the Nordic hamstring exercise to assess eccentric knee flexors strength : a reliability and retrospective injury study

STUDY DESIGN: Reliability and case-control injury study. OBJECTIVES: 1) To determine if a novel device, designed to measure eccentric knee flexors strength via the Nordic hamstring exercise (NHE), displays acceptable test-retest reliability; 2) to determine normative values for eccentric knee flexors strength derived from the device in individuals without a history of hamstring strain injury (HSI) and; 3) to determine if the device could detect weakness in elite athletes with a previous history of unilateral HSI. BACKGROUND: HSIs and reinjuries are the most common cause of lost playing time in a number of sports. Eccentric knee flexors weakness is a major modifiable risk factor for future HSIs, however there is a lack of easily accessible equipment to assess this strength quality. METHODS: Thirty recreationally active males without a history of HSI completed NHEs on the device on 2 separate occasions. Intraclass correlation coefficients (ICCs), typical error (TE), typical error as a co-efficient of variation (%TE), and minimum detectable change at a 95% confidence interval (MDC95) were calculated. Normative strength data were determined using the most reliable measurement. An additional 20 elite athletes with a unilateral history of HSI within the previous 12 months performed NHEs on the device to determine if residual eccentric muscle weakness existed in the previously injured limb. RESULTS: The device displayed high to moderate reliability (ICC = 0.83 to 0.90; TE = 21.7 N to 27.5 N; %TE = 5.8 to 8.5; MDC95 = 76.2 to 60.1 N). Mean±SD normative eccentric flexors strength, based on the uninjured group, was 344.7 ± 61.1 N for the left and 361.2 ± 65.1 N for the right side. The previously injured limbs were 15% weaker than the contralateral uninjured limbs (mean difference = 50.3 N; 95% CI = 25.7 to 74.9N; P < .01), 15% weaker than the normative left limb data (mean difference = 50.0 N; 95% CI = 1.4 to 98.5 N; P = .04) and 18% weaker than the normative right limb data (mean difference = 66.5 N; 95% CI = 18.0 to 115.1 N; P < .01). CONCLUSIONS: The experimental device offers a reliable method to determine eccentric knee flexors strength and strength asymmetry and revealed residual weakness in previously injured elite athletes.

Design of a professional development programme for palliative care nurses (Part Two)

Yates et al (1996) provided a review of the literature on educational approaches to improving psychosocial care of terminally ill patients and their families and suggested that there was an urgent need for innovation in this area. A programme of professional development currently being offered to 181 palliative care nurses in Queensland, Australia, was also described. This paper presents research in progress evaluating this programme which involves use of a quasi-experimental pre-post test design. It also includes process and outcome measures to assess effectiveness in improving the participant's ability to provide psychosocial care to patients and families. Research examining the effectiveness of various educational programmes on care of the dying has offered equivocal results (Yates et al 1996). Degner and Gow (1988a) noted that the inconsistencies found in research into death education result from inadequate study designs, variations in the conceptualisation and measurement of the outcomes of the programmes and flaws in data analysis. Such studies have often lacked a theoretical basis, few have employed well-controlled experimental designs, and the programme outcomes have generally been limited to the participant's 'death anxiety', or other death attitudes which have been variously defined and measured. Whilst Degner and Gow (1988b) have reported that undergraduate nursing students who participated in a care of the dying educational programme demonstrated more 'approach caring' behaviours than a control group, the impact of education programmes on patient care has rarely been examined. Failure to link education to nursing practice and subsequent clinical outcomes has, however, been seen as a major limitation of nursing knowledge in this area (Degner et al 1991). This paper describes an approach to researching the effectiveness of professional development programmes for palliative care nurses.

Peer mentorship in clinical education : outcomes of a pilot programme for first year students

Identifying effective strategies for promoting learning in the clinical setting continues to pose challenges for nurse educators. The aim of the present paper is to examine the potential that peer mentorship may have in helping nursing students to improve clinical learning outcomes. An example of a peer mentorship programme for nursing students undertaking their first clinical practicum is described, and preliminary findings from an evaluation of this pilot programme are presented. The results suggest that peer mentorship may be of some benefit to students, particularly in relation to reducing anxiety and improving confidence with clinical practice experiences, and is therefore a strategy which is worthy of further investigation.

Improving psychosocial care: a professional development programme

Despite the numerous reports of difficulties experienced by health care providers in providing psychosocial care to terminally ill patients and their families, few studies have yet been undertaken to examine the effectiveness of different educational approaches to addressing these issues. The aim of this paper is to describe a programme of professional development for palliative care nurses, which is currently being offered to 181 registered nurses in Queensland, Australia. The programme is based on an action learning model and is designed to facilitate processes of reflection and peer consultation. In Part One of this paper, a review of this literature is presented to provide the background and rationale for the programme design. Details of the research programme developed to evaluate the programme will be presented in Part Two of this paper, which is to be published in the next issue of this Journal. Surveys of health professionals suggest that the demands of working with terminally ill patients are associated with a great deal of stress (Beaton and Degner 1990, Seale 1992, Vachon 1995), and emotional burden, as they are confronted with their patients' physical and emotional suffering over extended periods of time (Ullrich and Fitzgerald 1990). Key areas of concern (Lyons 1988, Bramwell 1989, Seale 1992, Copp and Dunn 1993, Wilkinson 1995) include: * Handling questions and conversations with dying patients. * Dealing with ethical and moral issues. * Handling emotions. * Giving hope. * Providing spiritual care and bereavement support. * Confronting team communication problems.