Biomechanics

The knowledge of the onset and cessation timing of the paraspinal muscles that surround the lumbar spine is an important area of research for the understanding of low back pain. This study examined the timing of the erector spinae and external oblique muscle activity in a group of golfers with and without low back pain. The study compared the results of surface electromyography measurements for two groups of golfers. Twelve male golfers who had reported a mild or greater level of pain in the lower back that was experienced while playing golf were examined. A further fifteen male golfers who had reported no history of lower back pain in the previous 12 months were recruited as controls. The results showed that the low back pain golfers switched-on their erector spinae muscle significantly in advance of the start of the backswing. This finding was not evident in the group who did not have low back pain symptoms. Low back pain golfers therefore, may use the erector spinae muscle as a primary spinal stabiliser instead of the stronger deeper muscles such as transversus abdominis and multifidus. These results may have important implications for conditioning programmes for golfers with low back pain.

Anterior cruciate ligament (ACL) deficient and reconstructed knees display altered biomechanics during gait. Identifying significant gait changes is important for understanding normal and ACL function and is typically performed by statistical approaches. This paper focuses on the development of an explainable machine learning (ML) empowered methodology to: (i) identify important gait kinematic, kinetic parameters and quantify their contribution in the diagnosis of ACL injury and (ii) investigate the differences in sagittal plane kinematics and kinetics of the gait cycle between ACL deficient, ACL reconstructed and healthy individuals. For this aim, an extensive experimental setup was designed in which three-dimensional ground reaction forces and sagittal plane kinematic as well as kinetic parameters were collected from 151 subjects. The effectiveness of the proposed methodology was evaluated using a comparative analysis with eight well-known classifiers. Support Vector Machines were...

In this study Interlocking nails were used in order to fixate the canine femoral fractures and to examine the effects of the implants on fracture healing, clinically and radipgraphically in 19 dogs. The material of the study consisted 19 dogs of medium-large size, which were brought to Ankara University, Faculty of Veterinary Medicine, Department of Orthopedics and Traumatology because of injuries due to various trauma and consequent diaphyseal femur fractures clinically and radiologically. Following general anaesthesia, the broken extremity was operated, a total of 20 interlocking pins of different sizes were placed. Among the pins used with an appropriate diameter and length, 10 were 8-199 mm, 4 were 8-185 mm, 2 were 8-172, 1 was 8-165, 2 were 6-172 mm and another was 6-160 mm, respectively. In order to lock these pins 46, 3.5 mm diameter screws, with different length were used. It was observed that 1 screw in proximal and 1 screw in distal region, didn't hold in the holes of the pins. Statical nailing was performed in all cases but one. Cases were clinically examined for weight bearing and extremity usage and radiologically, the callus tissue development was monitored. As a result; the idea was that interlocking nailing technique was on alternative to plates by creating enough rigidity, to fixate 1/3 diaphyseal femoral fractures in medium and medium-large breed dogs. Köpeklerde Femur Kırıklarında Interlocking Çivisi Uygulamaları; Ondokuz Olguda Klinik Deneyim ve Sonuçlar Özet Bu çalışmada köpeklerde femur kırıklarında interlocking çivileme sistemi kullanılarak implantın kırık iyileşmesine olan etkileri ve kullanım kolaylığı klinik ve radyolojik olarak değerlendirilmiştir. Çalışmanın materyalini Ankara Üniversitesi Veteriner Fakültesi Ortopedi ve Travmatoloji Kliniği'ne getirilen ve yapılan klinik-radyolojik kontrollerde femur kırığı saptanan 19 adet orta-büyük ırktan köpek oluşturmuştur. Hastaların kırıkları genel anestezileri ve rutin operatif hazırlıkları tamamlandıktan sonra, toplam 20 adet, uygun çap ve uzunlukta interlocking çivileri ile onarılmıştır. Çalışmada 10 adet 8 mm çap 199 mm uzunlukta, 4 adet 8 mm çap 185 mm uzunlukta, 2 adet 8 mm çap 172 mm uzunlukta, adet 8 mm çap 165 mm uzunlukta, 2 adet 6 mm çap 172 mm uzunlukta ve bir adet 6 mm çap 160 mm uzunlukta çivi kullanılmıştır. Bu çiviler toplam 46 adet 3.5 mm çaplı farklı uzunluklarda vidalar ile sabitlenmiştir. 44 vida yerini bulurken 1 distal ve 1 proksimal vida çivi üzerindeki deliği tutmamış ve korteks ile çivi arasından geçmiştir. Bir olgu hariç tüm olgularda statik çivileme yapılmıştır. Olgular postoperatif dönemde klinik ve radyolojik olarak takip edilerek ekstremitelerini kullanma durumları ile kallus formasyonu izlenmiştir. Sonuç olarak interlocking çivileme sisteminin femur diafiz kırıklarında plaklara alternatif olarak kullanılabilecek gerekli stabiliteyi sağlayan bir alternatif olabileceği kanısına varılmıştır.

Post-activation potentiation (PAP) has been shown to increase force generation due to prior muscular activity which can acutely improve strength and power performance. Typically, heavy-loaded bench press has been used as a conditioning contraction for a PAP stimulus. However, a heavy loaded weight exercise is frequently not available prior to performance, due to varying factors such as regulations or practicality for athletes. The aim of this study was to examine whether lower load exercises can cause an induction of PAP.
Fourteen male, competitive university level athletes (mean ± SD: age, 21.9 ± 2.2 years; height 1.8 ± 0.05 m; body mass 76.3 ± 8.2 kg) performed an explosive bench press (with 50% 1RM load) immediately prior to one of four conditioning contractions; 2 x 45 seconds of suspended chest press, 3 x 8 repetitions of resistance band lying bench press, 3 x 10 repetitions of push-ups, or no conditioning contractions. Rest between all sets was 30 seconds and the conditioning contraction order was randomised. The explosive bench press was performed again at 2, 4, 6 and 8 minutes after the conditioning contraction. Peak power (Ppeak), peak force (Fpeak), peak velocity (Vpeak), rate of force development (RFD) and a percentage of EMG from the Pectoralis Major, Anterior Deltoid and Triceps Brachii were recorded for all trials and a maximum voluntary contraction (MVC). Normality of data was checked using the Shapiro-Wilks test and confirmed for Ppeak, Fpeak, Vpeak, and EMG triceps but not for RFD, EMG chest and EMG shoulder. Repeated measures ANOVA with Bonferroni correction was used to check for differences between normally distributed data, while a Friedman’s test was used to check for differences in RFD, EMG chest and EMG shoulder. A Wilcoxon Signed Ranks test was used to analyse the difference found in the data for EMG shoulder. 
The results showed no significant difference between the variables for any of the conditioning contractions between baseline, 2, 4, 6 and 8 minutes. Similarly, there was no significant difference in any variables was shown between conditioning contractions at baseline, 2, 4, 6 and 8 minutes. Whereas, EMG shoulder showed a difference in the RB intervention between trials 1 and 2 (Z = -2.480, p = 0.013), 1 and 4 (Z = -2.480, p = 0.013), 1 and 5 (Z = -2.103, p=  0.035) and trials 2 and 3 (Z = -2.103, p = 0.035), with a difference also found in the PU intervention, between trials 2 and 3 (Z = -2.229, p = 0.026) and trials 2 and 4 (Z = -2.103, p = 0.035).
The findings suggest that PAP was not induced by any of the conditioning contractions used in this study. As the design employed in the current study has been used previously showing higher weighted exercises inducing PAP, we conclude that a) the loading used in the current study was insufficient to induce PAP, b) there is a ‘load threshold’ below which PAP cannot be induced, c) the stimulus from the EMG was not high enough to induce PAP, and d) muscle excitation is not a contributing mechanism to an induction of PAP.

The main purpose of the present study was to investigate the kinematics and kinetics of successful versus unsuccessful basketball free throw shots. Six professional basketball players (age= 23±2.09 years members of Iranian premier basketball league participat in test. Kinematics of arm motion during basketball free throws were recorded by two Casio zr200 camera in frequency of 240 Hz. Wilcoxon test was used for significant differences between successful versus unsuccessful free throws (p ≤ 0/05). Angular velocity of the wrist was found to be significantly higher in successful versus unsuccessful shots at the time of ball release (p ≤ 0/028). Wrist (p ≤ 0/008) and shoulder (p ≤ 0/023) joints were found to have significantly more flexion in successful versus unsuccessful shots while elbow (p ≤ 0/002) remained significantly less flexed in successful shots. Angular displacement of wrist (p ≤ 0/034) and elbow (p ≤ 0/004) was shown to be significantly greater in successful versus unsuccessful shots. Integrated EMG of Anterior Deltoid (AD), Triceps Brachii (TB) and Flexor Carpi Radialis (FCR) muscles was more in successful free throw versus unsuccessful free throw, but the only significant difference was observed in the Integrated EMG of the Triceps Brachii muscle (p ≤ 0/034). In summery, increasing the wrist angular velocity and activity of triceps brachii muscle affected successful free throws.

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In presence of aortic stenosis, a jet is produced downstream of the aortic valve annulus during systole. The vena contracta corresponds to the location where the cross-sectional area of the flow jet is minimal. The maximal transvalvular pressure gradient (TPG(max)) is the difference between the static pressure in the left ventricle and that in the vena contracta. TPG(max) is highly time-dependent over systole and is known to depend upon the transvalvular flow rate, the effective orifice area (EOA) of the aortic valve and the cross-sectional area of the left ventricular outflow tract. However, it is still unclear how these parameters modify the TPG(max) waveform. We thus derived an explicit analytical model to describe the instantaneous TPG(max) across the aortic valve during systole. This theoretical model was validated with in vivo experiments obtained in 19 pigs with supravalvular aortic stenosis. Instantaneous TPG(max) was measured by catheter and its waveform was compared with the one determined from the derived equation. Our results showed a very good concordance between the measured and predicted instantaneous TPG(max). Total relative error and mean absolute error were on average 9.4+/-4.9% and 2.1+/-1.1 mmHg, respectively. The analytical model proposed and validated in this study provides new insight into the behaviour of the TPG(max) and thus of the aortic pressure at the level of vena contracta. Because the static pressure at the coronary inlet is similar to that at the vena contracta, the proposed equation will permit to further examine the impact of aortic stenosis on coronary blood flow.

Currently, cerebrovascular diseases are one of the main health problems. Part of the patient’s rehabilitation process, affected by this disease, is manually performed by a physiotherapist, which, due to physical exhaustion, could affect the performance of patient recovery. In this paper is proposed a robotic exoskeleton for upper limb rehabilitation, which enables assist or supports the therapist’s work. In the first stage, the exoskeleton is controlled passively through programmed commands and routines. Later, a second stage is proposed for biofeedback control system using the exoskeleton and signals acquired through bioinstrumentation equipment. This system will allows the acquisition of the surface electromyography signals (sEMG), as well as proprioceptive information for signal processing and movement’s intention detection of upper limb. As results, are presented the implementation of robotic arm commanded passively and the bioinstrumentation equipment is presented. In the rehabilitation field, this assistive technology will enable to medical staff, to contribute to recovery and welfare of the patient, affected by some kind of muscular dysfunction, with major effectiveness.

Whole body vibration (WBV) is a promising tool for counteracting bone loss. Most WBV studies on animals have been performed at acceleration <1g and frequency between 30 and 90Hz. Such WBV conditions trigger bone growth in osteopenia models, but not in healthy animals. In order to test the ability of WBV to promote osteogenesis in young animals, we exposed seven-week-old male mice to vibration at 90Hz and 2g peak acceleration for 15min/day, 5 days/week. We examined the effects on skeletal tissues with micro-computed tomography and histology. We also quantified bone vascularization and mechanosensitive osteocyte proteins, sclerostin and DMP1. Three weeks of WBV resulted in an increase of femur cortical thickness (+5%) and area (+6%), associated with a 25% decrease of sclerostin expression, and 35% increase of DMP1 expression in cortical osteocytes. Mass-structural parameters of trabecular bone were unaltered in femur or vertebra, while osteoclastic parameters and bone formation rat...

The velocity by which the disturbance travels through the medium is the wave velocity. Pulse wave velocity is one of the main parameters in hemodynamics. The study of wave propagation through the fluid-fill elastic tube is of great importance for the proper biophysical understanding of the nature of blood flow through of cardiovascular system. The effect of viscosity on the pulse wave velocity is generally ignored. In this paper we present the results of experimental measurements of pulse wave velocity (PWV) of compression and expansion waves in elastic tube. The solutions with different density and viscosity were used in the experiment. Biophysical model of the circulatory flow is designed to perform measurements. Experimental results show that the PWV of the expansion waves is higher than the compression waves during the same experimental conditions. It was found that the change in viscosity causes a change of PWV for both waves. We found a relationship between PWV, fluid density ...

Torticollis is a visible medical condition. Your child’s head constantly tilts to one side. Torticollis means twisted neck in Latin.  The condition is also called wry neck or twisted neck. Torticollis can be congenital or acquired. Congenital muscular torticollis is a condition affecting babies. Most parents don’t notice the defect until the baby is several weeks old. Toricollosis is a rare medical condition in India.

Fractures of metatarsal are most common fractures in children foot. Most common causes are direct injuries to the fore foot.Here we present a case of non union metatarsal shaft fracture with 90degrees deformity treated by open reduction and internal fixation with locking recon plate in a single sitting.