@article{QuarmbyMoennigMugeleetal.2023,
  author    = {Quarmby, Andrew and M{\"o}nnig, Jamal and Mugele, Hendrik and Henschke, Jakob and Kim, MyoungHwee and Cassel, Michael and Engel, Tilman},
  title     = {Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review},
  series = {Frontiers in Sports and Active Living},
  journal   = {Frontiers in Sports and Active Living},
  publisher = {Frontiers},
  address   = {Lausanne, Schweiz},
  issn      = {2624-9367},
  doi       = {10.3389/fspor.2022.1012471},
  pages     = {20},
  year      = {2023},
  abstract  = {Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95\% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of "medial collapse". Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn.},
  language  = {en}
}
@article{SandauGranacher2020,
  author    = {Sandau, Ingo and Granacher, Urs},
  title     = {Effects of the barbell load on the acceleration phase during the snatch in elite Olympic weightlifting},
  series = {Sports},
  volume    = {8},
  journal   = {Sports},
  number    = {5},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-4663},
  doi       = {10.3390/sports8050059},
  pages     = {10},
  year      = {2020},
  abstract  = {The load-depended loss of vertical barbell velocity at the end of the acceleration phase limits the maximum weight that can be lifted. Thus, the purpose of this study was to analyze how increased barbell loads affect the vertical barbell velocity in the sub-phases of the acceleration phase during the snatch. It was hypothesized that the load-dependent velocity loss at the end of the acceleration phase is primarily associated with a velocity loss during the 1st pull. For this purpose, 14 male elite weightlifters lifted seven load-stages from 70-100\% of their personal best in the snatch. The load-velocity relationship was calculated using linear regression analysis to determine the velocity loss at 1st pull, transition, and 2nd pull. A group mean data contrast analysis revealed the highest load-dependent velocity loss for the 1st pull (t = 1.85, p = 0.044, g = 0.49 [-0.05, 1.04]) which confirmed our study hypothesis. In contrast to the group mean data, the individual athlete showed a unique response to increased loads during the acceleration sub-phases of the snatch. With the proposed method, individualized training recommendations on exercise selection and loading schemes can be derived to specifically improve the sub-phases of the snatch acceleration phase. Furthermore, the results highlight the importance of single-subject assessment when working with elite athletes in Olympic weightlifting.},
  language  = {en}
}
@article{SeiffertHolsteinSchlosseretal.2017,
  author    = {Seiffert, Martin and Holstein, Flavio and Schlosser, Rainer and Schiller, Jochen},
  title     = {Next generation cooperative wearables},
  series = {IEEE access : practical research, open solutions},
  volume    = {5},
  journal   = {IEEE access : practical research, open solutions},
  publisher = {Institute of Electrical and Electronics Engineers},
  address   = {Piscataway},
  issn      = {2169-3536},
  doi       = {10.1109/ACCESS.2017.2749005},
  pages     = {16793 -- 16807},
  year      = {2017},
  abstract  = {Currently available wearables are usually based on a single sensor node with integrated capabilities for classifying different activities. The next generation of cooperative wearables could be able to identify not only activities, but also to evaluate them qualitatively using the data of several sensor nodes attached to the body, to provide detailed feedback for the improvement of the execution. Especially within the application domains of sports and health-care, such immediate feedback to the execution of body movements is crucial for (re-) learning and improving motor skills. To enable such systems for a broad range of activities, generalized approaches for human motion assessment within sensor networks are required. In this paper, we present a generalized trainable activity assessment chain (AAC) for the online assessment of periodic human activity within a wireless body area network. AAC evaluates the execution of separate movements of a prior trained activity on a fine-grained quality scale. We connect qualitative assessment with human knowledge by projecting the AAC on the hierarchical decomposition of motion performed by the human body as well as establishing the assessment on a kinematic evaluation of biomechanically distinct motion fragments. We evaluate AAC in a real-world setting and show that AAC successfully delimits the movements of correctly performed activity from faulty executions and provides detailed reasons for the activity assessment.},
  language  = {en}
}
@article{LesinskiPrieskeBordeetal.2018,
  author    = {Lesinski, Melanie and Prieske, Olaf and Borde, Ron and Beurskens, Rainer and Granacher, Urs},
  title     = {Effects of Different Footwear Properties and Surface Instability on Neuromuscular Activity and Kinematics During Jumping},
  series = {Journal of strength and conditioning research : the research journal of the NSCA},
  volume    = {32},
  journal   = {Journal of strength and conditioning research : the research journal of the NSCA},
  number    = {11},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1064-8011},
  doi       = {10.1519/JSC.0000000000002556},
  pages     = {3246 -- 3257},
  year      = {2018},
  abstract  = {The purpose of this study was to examine sex-specific effects of different footwear properties vs. barefoot condition during the performance of drop jumps (DJs) on stable and unstable surfaces on measures of jump performance, electromyographic (EMG) activity, and knee joint kinematics. Drop jump performance, EMG activity of lower-extremity muscles, as well as sagittal and frontal knee joint kinematics were tested in 28 healthy male (n = 14) and female (n = 14) physically active sports science students (23 6 2 years) during the performance of DJs on stable and unstable surfaces using different footwear properties (elastic vs. minimal shoes) vs. barefoot condition. Analysis revealed a significantly lower jump height and performance index (Delta 7-12\%; p < 0.001; 2.22 <= d = 2.90) during DJs on unstable compared with stable surfaces. This was accompanied by lower thigh/shank muscle activities (Delta 11-28\%; p < 0.05; 0.99 <= d = 2.16) and knee flexion angles (Delta 5-8\%; p < 0.05; 1.02 <= d = 2.09). Furthermore, knee valgus angles during DJs were significantly lower when wearing shoes compared with barefoot condition (Delta 22-32\%; p < 0.01; 1.38 <= d = 3.31). Sex-specific analyses indicated higher knee flexion angles in females compared with males during DJs, irrespective of the examined surface and footwear conditions (Delta 29\%; p < 0.05; d = 0.92). Finally, hardly any significant footwear-surface interactions were detected. Our findings revealed that surface instability had an impact on DJ performance, thigh/shank muscle activity, and knee joint kinematics. In addition, the single factors "footwear" and "sex" modulated knee joint kinematics during DJs. However, hardly any significant interaction effects were found. Thus, additional footwear-related effects can be neglected when performing DJs during training on different surfaces.},
  language  = {en}
}
@article{WippertRectorKuhnetal.2017,
  author    = {Wippert, Pia-Maria and Rector, Michael V. and Kuhn, Gisela and Wuertz-Kozak, Karin},
  title     = {Stress and Alterations in Bones},
  series = {Frontiers in endocrinology},
  volume    = {8},
  journal   = {Frontiers in endocrinology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-2392},
  doi       = {10.3389/fendo.2017.00096},
  pages     = {7},
  year      = {2017},
  abstract  = {Decades of research have demonstrated that physical stress (PS) stimulates bone remodeling and affects bone structure and function through complex mechanotransduction mechanisms. Recent research has laid ground to the hypothesis that mental stress (MS) also influences bone biology, eventually leading to osteoporosis and increased bone fracture risk. These effects are likely exerted by modulation of hypothalamic-pituitary-adrenal axis activity, resulting in an altered release of growth hormones, glucocorticoids and cytokines, as demonstrated in human and animal studies. Furthermore, molecular cross talk between mental and PS is thought to exist, with either synergistic or preventative effects on bone disease progression depending on the characteristics of the applied stressor. This mini review will explain the emerging concept of MS as an important player in bone adaptation and its potential cross talk with PS by summarizing the current state of knowledge, highlighting newly evolving notions (such as intergenerational transmission of stress and its epigenetic modifications affecting bone) and proposing new research directions.},
  language  = {en}
}