J. Funct. Morphol. Kinesiol., Volume 2, Issue 4 (December 2017) – 15 articles

An increasing number of young football athletes are competing in elite senior level competitions. However, comparison of strength, power, and speed characteristics between young elite football athletes and their senior counterparts, while controlling for anthropometric parameters, is yet to be investigated. Knee extension concentric peak torque, jump performance, and 20 m straight-line speed were compared between age groups of under 17 (U17: n = 24), under 19 (U19: n = 25), and senior (seniors: n = 19) elite, national and international level, male football athletes. Analysis of covariance was performed, with height and body mass used as covariates. No significant differences were found between age groups for knee extension concentric peak torque (p = 0.28–0.42), while an effect was observed when the covariates of height and body mass were applied (p < 0.001). Senior players had greater jump and speed performance, whereas an effect was observed only for the covariate of body mass in the 15 m and 20 m (p < 0.001) speed testing. No differences were observed between U17 and U19 groups for jump and speed performance (p = 0.26–0.46). The current study suggests that younger elite football athletes (<19 years) have lower jump and speed performance than their senior counterparts, but not for strength when height and body mass are considered as covariates. Emphasis should be on power development capacities at the late youth phase when preparing athletes for the senior competition level. Full article

Duchenne muscular dystrophy (DMD) is a lethal X-linked pathology due to lack of dystrophin and characterized by progressive muscle degeneration, impaired locomotion and premature death. The chronic presence of inflammatory cells, fibrosis and fat deposition are hallmarks of DMD muscle tissue. Many different therapeutic approaches to DMD have been tested, including cell-based and gene-based approaches, exon skipping, induction of expression of the dystrophin paralogue, utrophin, and, most recently the application of the CASPR/Cas9 genome editing system. However, corticosteroid treatment remains the gold standard therapy, even if corticosteroids have shown multiple undesirable side effects. Sertoli cells (SeC) have long been known for their ability to produce immunomodulatory and trophic factors, and have been used in a plethora of experimental models of disease. Recently, microencapsulated porcine SeC (MC-SeC) injected intraperitoneally in dystrophic mice produced morphological and functional benefits in muscles thanks to their release into the circulation of anti-inflammatory factors and heregulin β1, a known inducer of utrophin expression, thus opening a new avenue in the treatment of DMD. In order to stress the potentiality of the use of MC-SeC in the treatment of DMD, here, we examine the principal therapeutic approaches to DMD, and the properties of SeC (either nude or encapsulated into alginate-based microcapsules) and their preclinical and clinical use. Finally, we discuss the potential and future development of this latter approach. Full article

It is unknown how sports activity combined with blood flow restriction (BFR) on the limbs can impact the exercising limb’s motion. We aimed to compare the lower limb kinematics between submaximal sprinting with and without BFR cuffs (i.e., BFR and normal conditions) when they were applied on the upper thigh. Ten collegiate sprinters performed five 45-m submaximal sprint trials under normal and BFR conditions. The BFR was applied to both legs at the proximal portion of the thigh utilizing elastic cuffs. The cuff pressure was set at approximately 60% of estimated arterial occlusion pressure. Spatiotemporal and hip and knee joint kinematic variables for both legs during submaximal sprinting were obtained using a motion capture system. The results showed, for spatiotemporal variables, no significant difference (p > 0.653), a trivial or small effect size (0.050–0.205), and high correlation coefficients (r > 0.923) between conditions. Moreover, for the joint angles and angular velocities, no significant difference (p > 0.244) and a trivial or small effect size (0.003–0.538), as well as significant correlations (r >0.684) were found between conditions. These results indicate that, in general, there is probably no influence of BFR cuffs on the upper thigh on running kinematics. Full article

Duchenne muscular dystrophy (DMD) is an X-linked genetic disease in which the dystrophin gene is mutated, resulting in dysfunctional dystrophin protein. Without dystrophin, the dystrophin-glycoprotein complex (DGC) is unstable, leading to an increase in muscle damage. Moreover, the imbalance between muscle damage and repair leads to a chronic inflammatory response and an increase in the amount of fibrosis over time. The absence of dystrophin at the sarcolemma also delocalizes and downregulates nitric oxide synthase (nNOS) and alters enzymatic antioxidant responses, leading to an increase in oxidative stress. In this review, we analyze the pathogenic role of both inflammation and oxidative stress in muscular dystrophy. Full article

It remains unclear whether training in fasted compared to fed states leads to greater weight loss and whether this practice results in beneficial or detrimental changes in body composition. We conducted a systematic review to examine the effect of overnight-fasted versus fed exercise on weight loss and body composition. Seven electronic databases were searched using terms related to fasting and exercise. Inclusion criteria were: randomised and non-randomised comparative studies; published in English; included healthy adults; compared exercise following an overnight fast to exercise in a fed state; used a standardized pre-exercise meal for the fed condition; and measured body mass and/or body composition. A total of five studies were included involving 96 participants. Intra-group analysis for the effect of fasted and fed aerobic exercise revealed trivial to small effect sizes on body mass. The inter-group effect for the interventions on body mass was trivial. Intra-group effects were small for % body fat and trivial for lean mass in females, with trivial effects also found for the inter-groups analyses. Whilst this is the first systematic review and meta-analysis to investigate this topic, caution is warranted when interpreting the findings due to the limited number of studies and hence insufficient data. Full article

The analysis of tissue network characteristics and cell distribution using histological methods is widely used. However, image analysis still relies on manual evaluation methods, known as semi-quantitative analysis, which are time-consuming and to a certain degree user-specific. For this reason, automated imaging processing methods have an enormous potential to increase sample processing and reduce the variation that is caused by a user-specific evaluation. This work demonstrates the feasibility of using a semi-automated image analysis process based on the open source software framework ImageJ and the plug-in Angiogenesis Analyzer to evaluate the quantitative degree of tissue damage within 3D cell constructs after mechanical loading. Within a proof-of-concept study, the semi-automated approach was applied to calculate the Node-to-Free Ratio (N/F-Ratio) and perform a strut analysis for histological evaluation of mechanically compressed samples of human osteoblast-derived 3D constructs. The N/F-Ratio revealed a median value of 1.29 for the control, whereas the values for the mechanically compressed samples decreased to 0.97 for 20% compression, 0.85 for 40%, and 0.86 for 60%. The strut analysis indicated a decrease of the connected branches with increasing compression rate. The newly developed and time-saving processing workflow was successfully established and can be carried out using available, open source software solutions. Full article

Transforming growth factor β (TGF-β) is a key regulator of bone density. Recently, we have shown that TGF-β₁ effectively blocks bone morphogenetic protein-induced maturation of human osteoblasts (hOBs) in a histone deacetylase (HDAC)-dependent manner. To better understand the underlying mechanisms and to identify possible therapeutic targets, the current study aimed at characterizing the expression changes of different HDACs in hOBs following recombinant human TGF-β₁ treatment and investigating the effect of the altered HDACs on both the proliferation and maturation of hOBs and osteogenic cell lines. As expected from our previous work, exposure to rhTGF-β₁ induced the expression of HDACs (HDAC1, -2, -3, -6). However, to our surprise, rhTGF-β₁ treatment strongly suppressed the expression of HDAC9 during osteogenic differentiation. HDAC9 is reported to suppress osteoclastogenesis; however, little is known about the role of HDAC9 in osteogenesis. Chemical inhibition of HDAC9 with TMP269 increased cell numbers of hOBs, but significantly decreased their osteogenic function (alkaline phosphatase activity and matrix mineralization). In osteogenic cell lines (MG-63, CAL-72 and SAOS-2), the expression of HDAC9 negatively correlates with their proliferation capacity and positively correlates with their osteogenic differentiation potential. Being able to boost osteoclasts while inhibiting osteoblasts makes HDAC9 an interesting therapeutic target to support fracture healing and bone metabolisms. Full article

Skeletal muscle mass reduction might be a consequence of aging (sarcopenia), disease (cachexia) or inactivity (muscle atrophy). Studying the triggering factors leading to muscle loss is important in developing therapies to preserve muscle tissue function. The loss of skeletal muscle proteins is caused by an imbalance between the rate of their synthesis and degradation. Specifically, the conditions characterized by muscle loss involve an adaptation metabolism of increased protein degradation (cachexia), decreased muscle protein synthesis (inactivity), or alteration in both (sarcopenia). Sarcopenia and exercise is the main topic chosen for this review. This is a huge health problem, poorly discussed in the current literature and the aim of this review is to explain and help readers to better understand the differences between “sarcopenia”, “cachexia”, “muscle atrophy” and the relative beneficial effects of exercise used as a possible therapeutic intervention. Sarcopenia is a component of the fragility syndrome and indicates a significant health issue related to the progressive decline of muscle tissue quality and strength. Exercise is associated with improved life quality, reduced health problems, and prolonged lifespan. The latter suggests that exercise should be considered a fundamental point in the treatment of pathological skeletal muscle mass reduction. The present scientific contribution also seeks to emphasize to the scientific community the positive effects of the adapted physical activity in the elderly as a possible non-pharmacologic treatment to prevent or treat muscle atrophy. Full article

Muscular dystrophies (MDs) are inheritable diseases caused by mutations in specific genes encoding muscle proteins and characterized by progressive muscle wasting and weakness. MDs are classified into nine main categories, encompassing approximately 30 different diseases. Duchenne muscular dystrophy and Becker muscular dystrophy (DMD and BMD) are the most commonly diagnosed neuromuscular disorders, affecting respectively ~1/3500 and 3–6/100,000 male infants worldwide. DMD is characterized by absence of dystrophin function due to complete loss of expression or to the presence of a non-functional dystrophin protein in muscle tissue, while a semi-functional dystrophin isoform is typically present in BMD. Lack of dystrophin function in MDs induces myofiber damage, causing persistent cycles of degeneration/regeneration, exhaustion of regenerative potential and fibrosis, and resulting in muscle degeneration. Cancer cachexia is a multifactorial syndrome characterized by severe body weight loss and muscle degenerative atrophy. Up to 80% of cancer patients show cachexia, and the syndrome has been estimated to cause ~2 million of deaths per year. This cancer-related muscle wasting is mediated by pro-inflammatory cytokines and tumor-released mediators able to activate specific catabolic pathways in muscle tissue. MDs and cancer-associated cachexia (CAC) share some peculiar features, including systemic and muscle-specific inflammation, alteration of myogenic potential, ultrastructural abnormalities, and dysfunction of the dystrophin glycoprotein complex (DCG). This review focuses on the pathophysiological comparison between these two chronic muscle degenerative conditions and discusses the most relevant and promising therapeutic strategies considered so far. Full article

Current evidence suggests that physical activity interventions can improve quality of life, fitness, and strength, reducing depression and fatigue in breast cancer survivors. However, in the long-term many survivors are insufficiently active. Here, the possible long-term benefits of a specific adapted physical activity (APA) intervention on upper limb functional performance and quality of life in breast cancer survivors were investigated. For this purpose, fifteen survivors were assessed by fitness tests (shoulder-arm mobility, range of motion, back flexibility) at the baseline and at eight weeks post-APA intervention. Quality of life and surgical shoulder and back pain intensity were evaluated by Short Form-12 and numerical rating scale questionnaires, respectively. Five participants, who continued to follow the APA protocol over time, were again evaluated after two years and compared to either five women who were inactive or five others who practiced general physical activity after ending the eight-week APA protocol. Shoulder-arm mobility and self-reported questionnaire data revealed the maintenance and/or improvement of the achieved benefits two years after the APA intervention. Our findings suggest that the long-term practice of APA tailored to individual characteristics should be recommended to breast cancer survivors in order to preserve quality of life and fitness. Full article

Many bodybuilders use anabolic androgenic steroids (AAS) to potentiate muscle mass gain as a result of specific resistance training and nutrition. The case we describe hereafter outlines alterations in body composition of an amateur bodybuilder during his pre-competitive period (11 weeks). The Participant was a 28-year old Caucasian male who was aiming to participate in his first bodybuilding competition under the “Men’s Physique” category. The Participant self-administered AAS for the whole pre-competitive period, followed a 13 set-meal plan consisting of 10 daily meals interspersed by approximately 2 h, and performed six high-volume resistance-training sessions a week. Body mass and anthropometric variables were measured at the beginning, during and at the end of his pre-competitive period. Dietetic analysis revealed a reduction in protein intake at the 10th (% decrease: −51.3%) and 11th weeks (% decrease: −64.5%) and in calorie intake at the 10th (% decrease: −57.9%) and 11th weeks (% decrease: −59.5%) in comparison to the 1st week. As a result, the Participant reduced both total body mass and fat percentage. However, there was a reduction in absolute fat free mass, despite the use of AAS. Apparently, the combination of excessive volumes of training with inadequate protein consumption was responsible for this outcome. Full article

We are pleased to introduce the sixth Journal Club. This edition is focused on several relevant studies published in the last years in the field of Strength and Conditioning, chosen by our Editorial Board members and their colleagues. We hope to stimulate your curiosity in this field and to share with you the passion for sport and exercise seen from a scientific point of view. The Editorial Board members wish you an inspiring read. Full article

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing health epidemic in developed countries with increased prevalence in obese and diabetic populations. Exercise is an established and essential component of lifestyle modification for NAFLD disease management. Despite numerous studies reporting exercise-mediated improvements in NAFLD, there remains a large gap in our knowledge of how to optimize exercise prescriptions and whether the benefits of exercise extend beyond improvements in liver fat. In this review, we summarize studies that have investigated the independent effects of exercise training on liver enzymes, hepatic fat, and histologic markers in NAFLD. Overall, 12-weeks of aerobic, resistance, the combination of aerobic and resistance, and novel training modalities, including acceleration and hybrid training, significantly improve liver enzymes and hepatic fat. The greatest benefits in NAFLD may occur through the combination of aerobic and resistance training that targets both cardiorespiratory fitness, and mediators of skeletal muscle, known as myokines. Understanding the role of myokines in the beneficial effects of exercise in NAFLD may identify future therapeutic targets that can be modified with tailored exercise prescriptions. Full article

Knee instability has been the focus of large number of studies over the last decade; however, a high incidence rate of injury still exists. The aim of this short report is to examine knee joint anatomy and physiology with respect to knee stability. Knee joint stability requires the integration of a complex set of anatomical structures and physiological mechanism. Compromising any of these structures leads to destabilisation and increased risk of injuries. This review highlights the structure and soft tissue of the knee that contribute to its stability and function. This introduction is part of the Journal of Functional Morphology and Kinesiology’s Special Issue “The Knee: Structure, Function and Rehabilitation”. Full article