; McCluskey et al., 2010 ; Zinner et al., 2015 ). Nevertheless, the influence of shoulder rotator performance on throwing velocity has never been evaluated. Analysis of women’s water polo game revealed that water polo can be characterised as a high intensity intermittent sport ( Tan et al., 2009a ). Players perform approximately 54 high intensity activities per game, one every 38 s ( Tan et al., 2009a ). Elite players generally exhibit sprinting and endurance swimming abilities ( Tan et al., 2009b ). During swimming, the shoulder also moves into internal rotation
Nicolas Olivier and Frédéric N. Daussin
1 Introduction The purpose of this paper is to introduce and analyze a nonlinear, dispersive model for the one-way propagation of long internal waves of small amplitude along the interface of a two-layer system of fluids under gravity, surface tension and rotational effects. The model can be derived from different points of view; rotating- and nonrotating-fluid models proposed in the literature, mainly the Ostrovsky equation, [ 12 , 25 ], and the Benjamin equation, [ 1 , 3 , 4 , 5 ], respectively. The analysis of the new system, exposed in the present
Marcin Popieluch, Jacek Zieliński and Marek Jędrysik
Evaluation of Torque of the Shank Rotating Muscles and the Range of Active Internal and External Rotation of the Knee Joint in Patients Awaiting ACL Reconstruction
Purpose. The aim of the study was threefold: to determine the active rotation range of a healthy and post-traumatic knee joint; to evaluate the torque of muscles responsible for internal and external rotation of a healthy and post-traumatic knee joint; and to determine differences between a healthy knee joint and knee joint with the ruptured anterior cruciate ligament (ACL). Differences between active axial rotation and muscular strength of rotators in the healthy and post-traumatic knee joints of 40 hospitalized patients were examined. Basic procedures. The static torque evaluation of the shank rotating muscles included 40 patients of the Endoscopic Surgery Clinic in Żory, with the ruptured ACL of the right knee, qualified for surgery (ACL reconstruction). On the basis of a medical interview, the ACL ruptures were found to have occurred during football games. Main findings. ACL damage leads to an increased rotation range, with a subsequent decrease of the rotators' strength and increased joint instability. The patients examined showed a substantial level of thigh quadriceps atrophy - a typical symptom associated with an ACL rupture. Our findings indicate that the internal and external rotators in intact knees were stronger than the rotators in post-traumatic knees (p < 0.05). Conclusions. The analysis of the torque of the shank rotating muscles at two knee joint flexion angles was an attempt to proceed with a laboratory diagnosis of the condition of the motor system in 40 patients following severe trauma (such as the ACL rupture of the right knee) prior to surgical intervention, and, in a longer perspective, after treatment completion. The results obtained will supposedly be useful as indicators for future rehabilitation pathways, and of the condition of the motor system following treatment completion.
Inese Pontaga and Janis Zidens
Werner SL, Gill TJ, Murray TA, Cook TD, Hawkins RJ. Relationship between throwing mechanics and shoulder distraction in professional baseball pitchers. Am J Sports Med, 2001; 29: 354 - 358 Wilk KE, Andrews CA, Arrigo MA, Kerns MA, Erber DJ. The strength characteristics of internal and external rotator muscles in professional baseball pitchers. Am J Sports Med, 1993; 21: 61 - 66
Daniel Collado-Mateo, Francisco J. Dominguez-Muñoz, Nuno Batalha, Jose Parraça, Pablo Tomas-Carus and Jose C. Adsuar
Introduction Competitive swimming performance is influenced by muscular strength ( Garrido et al., 2010 ; Maszczyk et al. 2012 ). Shoulder internal rotators have an extremely relevant role in developing propulsive forces responsible for the whole body displacement in freestyle swimming ( Holt et al., 2017 ; Yanai et al., 2000 ). Upper body force needed to move the swimmer through the water, especially when executing three of the four strokes (freestyle, butterfly, and backstroke), derives primarily from shoulder adduction and internal rotation ( Johnson et
Mohammad Reza Ghafoor Elahi and Masoud Mahdizadeh Rokhi
References  B. Takabi. Thermomechanical transient analysis of a thick-hollow FGM cylinder. Engineering Solid Mechanics, 4(1):25-32, 2016. doi: 10.5267/j.esm.2015.10.002.  M. Shariati, M.M. Rokhi, and H. Rayegan. Investigation of stress intensity factor for internal cracks in FG cylinders under static and dynamic loading. Frattura ed Integrità Strutturale, (39):166-180, 2017. doi: 10.3221/IGF-ESIS.39.17.  T. Meshii and K. Watanabe. Closed form stress intensity factor of an arbitrarily located inner
Athanasios A. Dalamitros, Vasiliki Manou, Kosmas Christoulas and Spiros Kellis
. Developments in the use of the hamstring/quadriceps ratio for the assessment of the muscle balance. J Sport Sci Med, 2002; 1: 56-62 Dekerle J, King L. Fatigue of the shoulder’s internal rotators following a 200-m all-out swim. In: Mason B, editor. XIIth International Symposium on Biomechanics and Medicine in Swimming. Australian Institute of Sport, Canberra, Australia, pp. 399-404; 2014 Deschodt V. Relative contribution of arms and legs in human to propulsion in 25 m sprint front crawl swimming. Eur J Appl Physiol, 1999; 80: 192
Adam Czaplicki, Marcin Śliwa, Paulina Szyszka and Jerzy Sadowski
). Biomechanical assessment of the strength of volleyball players in different stages of the training macrocycle. Polish Journal of Sport and Tourism 22, 148-152. 10. van Cingel R., Kleinrensink G., Stoeckart R., Aufdemkampe G., de Bie R., Kuipers H. (2006). Strength values of shoulder internal and external rotators in elite volleyball players. Journal of Sport Rehabilitation 15, 237-245. 11. Edouard P., Samozino P., Julia M., Carvera S., Vanbierviet W., Cameles P. et al. (2011). Reliability of isokinetic assessment of shoulder-rotator strength: a systematic
Aneta Popieluch, Michał Staniszewski and Michał Wychowański
-chain integration, Part 1: Concepts of functional shoulder movement. International Journal of Athletic Therapy & Training 11(4), 63-65. 4. Tetreault P., Levasseur A., Lin J.C., Nuno N., Guise J., Hagemeister N. (2011). Passive contribution of the rotator cuff to abduction and joint stability. Surgical and Radiologic Anatomy 33(9), 767-773. 5. Ignasiak Z., Domaradzki J. (2013). Anatomy of the locomotor system. Wrocław: Elsevier Urban & Partner. [in Polish] 6. Bober T., Hay J.G. (1991). Selecting angular positions for the measurement of peak torque in the
Agnieszka Witke-Woźniak, Michał Wychowański, Tomasz Dąmbski, Karina Szymfel and Tomasz Kochański
Introduction: Snapping hip syndrome (SHS) occurs in 5-10% of the global population. A back and forth skip of the tendon of the dysfunctional muscle across the osseous prominence is the most common symptom of this condition. Mainly young generation suffers from SHS. Depending on the structures that cause an audible snap, snapping hip syndrome may be classified into intra-articular and extra-articular types. The main aim of the research was to assess the strength of the major hip muscles and static balance in patients with snapping hip syndrome.
Material and methods: The research was carried out on 10 untrained females and 10 untrained males with extra-articular snapping hip syndrome. An average age was approximately 25 years. The research was conducted with the use of interview questionnaire, clinical examination, balance assessment on the JBA Staniak 4P dynamometric platform and measurements of the hip muscle strength on the JBA Staniak SPB2 set.
Results: Patients with SHS manifested an increased tension in iliotibial band, while significant weakening of internal and external rotator muscle strength was noted in women and significant weakening of external rotator muscle strength was observed in men. No correlations between hip muscles strength and stabilographic test results in patients with snapping hip syndrome were found.
Conclusions: Individuals with SHS and healthy persons demonstrate similar balance levels. The treatment of snapping hip syndrome should include: 1) restoring internal rotator muscle strength in women, 2) restoring external rotator muscle strength both in women and in men, as well as 3) restoring iliotibial band flexibility.