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This study investigated the effects of a 10-month high-intensity interval-type neuromuscular training programme on musculoskeletal fitness in overweight and obese women. Forty-nine inactive females (36.4 ± 4.4 yrs) were randomly assigned to either a control (N = 21), a training (N = 14, 10 months) or a training-detraining group (N = 14, 5 months training followed by 5 months detraining). Training used progressive loaded fundamental movement patterns with prescribed work-to-rest intervals (1:2, 1:1, 2:1) in a circuit fashion (2-3 rounds). Muscular strength and endurance, flexibility, passive range of motion (PRoM), static balance, functional movement screen (FMS) and bone mass density (BMD) and content (BMC) were measured at pre-, mid-, and post-intervention. Ten months of training induced greater changes than the controls in (i) BMD (+1.9%, p < 0.001) and BMC (+1.5%, p = 0.023) ii) muscular strength (25%-53%, p = 0.001-0.005); iii) muscular endurance (103%-195%, p < 0.001); and iv) mobility (flexibility: 40%, p < 0.001; PRoM [24%-53%, p = 0.001-0.05;]; balance: 175%, p = 0.058; FMS: +58%, p < 0.001). The response rate to training was exceptionally high (86-100%). Five months of detraining reduced but not abolished training-induced adaptations. These results suggest that a hybrid-type exercise approach integrating endurance-based bodyweight drills with resistance-based alternative modes into a real-world gym setting may promote musculoskeletal fitness in overweight and obese women.

Context: The effects of an exercise program (EP) for the treatment of patellofemoral pain syndrome (PFPS) are well known. However, the effects of osteopathic manipulative treatment (OMT) are unclear., Objective: To evaluate the effects of OMT versus EP on knee pain, functionality, plantar pressure in middle foot (PPMF), posterior thigh flexibility (PTF), and range of motion of hip extension in runners with PFPS., Design: This is a randomized controlled trial., Setting: Human performance laboratory., Participants: A total of 82 runners with PFPS participated in this study., Interventions: The participants were randomized into 3 groups: OMT, EP, and control group. The OMT group received joint manipulation and myofascial release in the lumbar spine, hip, sacroiliac joint, knee, and ankle regions. The EP group performed specific exercises for lower limbs. The control group received no intervention., Main Outcome Measures: The main evaluations were pain through the visual analog scale, functionality through the Lysholm Knee Scoring Scale, dynamic knee valgus through the step-down test, PPMF through static baropodometry, PTF through the sit and reach test, and range of motion through fleximetry. The evaluations were performed before the interventions, after the 6 interventions, and at 30-day follow-up., Results: There was a significant pain decrease in the OMT and EP groups when compared with the control group. OMT group showed increased functionality, decreased PPMF, and increased PTF. The range of motion for hip extension increased only in the EP group., Conclusion: Both OMT and EP are effective in treating runners with PFPS.

Context: Hamstring muscle tightness is one of the most common problems in athletic and healthy people. Dry needling (DN) was found to be an effective approach for improving muscle flexibility, but there is no study to compare this approach with static stretching (SS) as a common technique for the increase of muscle length., Objective: To compare the immediate effects of DN and SS on hamstring flexibility in healthy subjects with hamstring tightness., Study Design: A single-blind randomized controlled trial., Setting: A musculoskeletal physiotherapy clinic at Tehran University of Medical Sciences., Subjects: Forty healthy subjects (female: 32, age range: 18-40 y) with hamstring tightness were randomly assigned into 2 groups of DN and SS., Intervention: The DN group received a single session of DN on 3 points of the hamstring muscles, each for 1 minute. The SS group received a single session of SS of the hamstrings, consisting of 3 sets of 30-second SS with a 10-second rest between sets in the active knee extension test (AKET) position., Main Outcome Measures: The AKET, muscle compliance, passive peak torque, and stretch tolerance were measured at the baseline, immediately, and 15 minutes after the interventions., Results: Improvements in all outcomes was better for the DN group than for the SS group. DN increased muscle compliance significantly 15 minutes after the intervention, but it did not improve in the SS group., Conclusion: DN is effective in improving hamstring flexibility compared with SS. One session of DN can be an effective treatment for hamstring tightness and increase hamstring flexibility. The improvements suggest that DN is a novel treatment for hamstring flexibility.

BACKGROUND This study aimed to quantify the outcomes of combining Schroth and Pilates exercises on the Cobb angle, angle of trunk rotation (ATR), chest expansion, flexibility (trunk flexion), and quality of life (QoL) in adolescents with mild and moderate idiopathic scoliosis. MATERIAL AND METHODS Sixty-nine adolescents with idiopathic scoliosis aged 10-17 years, presenting with a Cobb angle of 10-45º were enrolled in this study. The treatment protocol, including selected exercises from Schroth and Pilates methods, was performed over 24 weeks and consisted of 2 periods of 2-week treatment regimens performed daily for 60 minutes. Each of treatment periods was then followed by the same home program treatment for 10 weeks. Cobb angle (x-rays), ATR (Scoliometer), chest expansion (cm), trunk flexion (cm, distance between C7 to S2 with measuring tape), and QoL (SRS-22r Scoliosis Research Society Questionnaire) were assessed pre-treatment, at 12 week, and at 24 weeks. RESULTS Significant improvements (P<0.05) were found in both groups of patients wearing and not wearing a brace for Cobb angle (from 21.97±4.99° to 18.11±6.39°; from 14.19±3.11° to 11.66±2.73°), angle of trunk rotation (from 7.19±1.36° to 5.36±1.66°; from 4.72±1.04° to 3.58±0.94°), chest expansion (from 2.56±0.84 cm to 3.46±0.72 cm; from 2.57±0.87 cm to 3.52±0.72 cm), trunk flexion (from 9.55±1.95 cm to 14.33±2.40 cm; from 9.82±2.61 cm to 13.98±2.18 cm) and QoL (from 3.50±0.27 to 3.82±0.2; from 3.42±0.24 to 3.78±0.23) respectively. CONCLUSIONS This study showed that combined exercises provided benefit on the Cobb angle, ATR, chest expansion, trunk flexion and QoL in adolescents with mild and moderate idiopathic scoliosis.

Background and objectives: People with multiple sclerosis (MS) often experience limitations in joint range of motion, which is linked to spasticity and continued inactivity. Low flexibility levels in this population have been linked to postural problems and muscular pain. Therefore, the purpose of this study was to conduct a systematic review and a meta-analysis aimed at identifying the characteristics and methodological quality of investigations studying the effects of exercise interventions on the flexibility levels of people with MS. Materials and Methods: Three electronic databases (MEDLINE/PubMed, SPORTDiscus and Scopus) were systematically searched up to May 2019 for intervention studies focused on the effects of exercise on the flexibility levels of people with MS. A meta-analysis, including randomized controlled trials (RCT), which reported information regarding the effects of exercise on flexibility, was also conducted. The methodological quality of included studies was assessed using the Physiotherapy Evidence Database, and the Quality Assessment Tool for Before-After Studies, with no control group. The quality of the information reported, regarding the programs conducted, was assessed by means of the Consensus on Exercise Reporting Template (CERT) scale. Results: Seven studies, four RCTs and three uncontrolled investigations were finally selected. The methodological quality of the RCTs was considered "poor" in one study, and "good" and "excellent" in two studies and one investigation, respectively. The three uncontrolled studies showed a methodological quality between "fair" and "poor". Following the CERT scale, four studies were graded as "high" and three as "low". Findings from the meta-analysis indicated no significant effects on hamstring flexibility, or the range of motion in the hips, knees or ankles. Conclusions: There is preliminary evidence from individual studies which indicates that people with MS can improve their lower limb flexibility following participation in physical exercise programs, but the meta-analysis did not confirm these findings., Competing Interests: Authors declare no conflict of interest.

Life span developmental theories suggest that as individuals age, they accumulate knowledge about how to deploy emotion regulation (ER) strategies effectively and learn how to match their ER strategy use with changes in situational demands. Using an event-contingent experience sampling design wherein 150 adults Age 18 to 89 years reported on 64,213 social interactions (M = 427.41, SD = 145.66) during 9 weeks of daily life, this study examines (a) age-related differences in individuals' usual ER strategy use (reappraisal, suppression) during everyday social interactions, (b) age-related differences in how much individuals' use of these two strategies varies across social situations-ER variability, and (c) age-related differences in the extent to which ER strategy use covaries with relational (close vs. nonclose others) and emotional (happy, sad) contextual features of those social situations-ER flexibility. In line with a small body of prior work, usual ER strategy use did not differ across adulthood and ER variability was lower at older ages. Results from multilevel models of intraindividual covariation suggested that individuals flexibly matched their ER strategy implementation to changes in emotional context-especially when interacting with close others. The results also provided evidence that the intraindividual covariation between relational context and use of suppression was weaker at older ages. Beyond these specific findings, this study demonstrated the utility of experience sampling designs, event-contingent reports, and the measurement/modeling of intraindividual variation and covariation for study of emotional development across the life span. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

To progress to a high level in classical ballet, en pointe is a requirement. The aim of this literature review was to evaluate the available evidence relating to readiness for dancing en pointe, including injury rates in the adolescent dancer population, screening tools, and pre-pointe training methods. It has been emphasized that young dancers are a demographic at increased risk of injury, especially as they progress through the growth spurt and increase their training hours. Dancers are commonly screened at the pre-pointe level, but unfortunately the majority of evidence resulting from this process, as reported in the literature, is subjective in nature. Hence, there is large variance regarding an appropriate time or level to commence en pointe training, and it remains unclear what dance teachers should be looking for in making this decision. A further paucity of evidence is demonstrated with regard to pre-pointe training protocols or instruction; in this review, no published literature was found on the topic. As such, there is a clear need for further study of pre-pointe screening and en pointe training protocols.

In standing, coordinated activation of lower extremity muscles can be simplified by common neural inputs to muscles comprising a functional synergy. We examined the effect of task difficulty on common inputs to agonist-agonist (AG-AG) pairs supporting direction specific reciprocal muscle control and agonist-antagonist (AG-ANT) pairs supporting stiffness control. Since excessive stiffness is energetically costly and limits the flexibility of responses to perturbations, compared to AG-ANT, we expected greater AG-AG common inputs and a larger increase with increasing task difficulty. We used coherence analysis to examine common inputs in three frequency ranges which reflect subcortical/spinal (0-5 and 6-15 Hz) and corticospinal inputs (6-15 and 16-40 Hz). Coherence was indeed higher in AG-AG compared to AG-ANT muscles in all three frequency bands, indicating a predilection for functional synergies supporting reciprocal rather than stiffness control. Coherence increased with increasing task difficulty, only in AG-ANT muscles in the low frequency band (0-5 Hz), reflecting subcortical inputs and only in AG-AG group in the high frequency band (16-40 Hz), reflecting corticospinal inputs. Therefore, common neural inputs to both AG-AG and AG-ANT muscles increase with difficulty but are likely driven by different sources of input to spinal alpha motor neurons.

Understanding how ligand binding influences protein flexibility is important, especially in rational drug design. Protein flexibility upon ligand binding is analyzed herein using 305 proteins with 2369 crystal structures with ligands (holo) and 1679 without (apo). Each protein has at least two apo and two holo structures for analysis. The inherent variation in structures with and without ligands is first established as a baseline. This baseline is then compared to the change in conformation in going from the apo to holo states to probe induced flexibility. The inherent backbone flexibility across the apo structures is roughly the same as the variation across holo structures. The induced backbone flexibility across apo-holo pairs is larger than that of the apo or holo states, but the increase in RMSD is less than 0.5 Å. Analysis of χ1 angles revealed a distinctly different pattern with significant influences seen for ligand binding on side-chain conformations in the binding site. Within the apo and holo states themselves, the variation of the χ1 angles is the same. However, the data combining both apo and holo states show significant displacements. Upon ligand binding, χ1 angles are frequently pushed to new orientations outside the range seen in the apo states. Influences on binding-site variation could not be easily attributed to features such as ligand size or x-ray structure resolution. By combining these findings, we find that most binding site flexibility is compatible with the common practice in flexible docking, where backbones are kept rigid and side chains are allowed some degree of flexibility., Competing Interests: The authors have declared that no competing interests exist.

While an important step in a young dancer's ballet career is the transition to pointe work, there is much controversy as to when her body is physically prepared to meet the increased demands of this development. Pointe screening protocols are being used by many in both the dance studio and dance science communities, but these protocols have not yet been standardized. The purpose of this study was to evaluate objectively the attributes of ballet dancers who are pre-pointe compared to those who have recently begun pointe training, and secondarily to correlate these quantitative findings with qualitative evaluations by the dancers' teachers. Participants were 49 healthy young female dancers with at least 1 year of formal ballet training. Twentyeight were pre-pointe students (age: 10.21 ± 1.17 years; height: 124.05 ± 13.45 cm; weight: 39.13 ± 13.18 kg; and 6.04 ± 1.84 years dance experience), and 21 were pointe students (age: 11.42 ± 0.81 years; height: 136.91 ± 16.04 cm; weight: 40.79 ± 8.77 kg; and 6.45 ± 2.07 years dance experience). Six dependent variables were evaluated: non-weightbearing (NWB) plantar flexion (PF) and dorsiflexion (DF) range of motion (ROM); weightbearing lunge test (WBL); relevé endurance (heel raise test); PF isometric strength; Airplane test; and Star Excursion Balance Test (SEBT) in three directions. These tests were broken into three categories for statistical analysis: ROM (NWB PF and DF, WBL), muscular capacity (relevé endurance, PF isometric strength), and balance (Airplane, SEBT). The analysis demonstrated that the pointe group performed significantly better than the pre-pointe group on the muscular capacity and balance testing (p < 0.01). Calculations for both tests indicated that 15 continuous single-leg relevés and two repetitions of the Airplane test may be the best cut-off levels when using these tests as part of a pre-pointe screening protocol. In conclusion, the relevé endurance test and the Airplane test are appropriate for use in differentiating between pre-pointe and pointe dancers.

This study examines the association between childhood socioeconomic position and objective physical capability including new functional measures of potential relevance to a population in late-middle age. The study population covers two Danish birth cohorts followed-up in the Copenhagen Aging and Midlife Biobank (age 48-58 years, 2009-2011, N = 4,204). Results from linear regression models revealed that being born in higher socioeconomic position was associated with higher jump height: Paternal occupational class four = 0.19 cm (95% confidence interval (CI): -0.44, 0.82), three = 0.59 cm (95% CI: -0.02, 1.19), two = 1.29 cm (95% CI: 0.64, 1.94), and one = 1.29 cm (95% CI: 0.45, 2.13) (reference = five); medium parental social class = 0.88 cm (95% CI: 0.03, 1.72) and high = 1.79 cm (95% CI: 0.94, 2.63) (reference = low). Higher childhood socioeconomic position was also associated with better chair rise performance and hand grip strength, while among women it was related to reduced flexibility: Medium parental social class = -1.31 cm (95% CI: -3.05, 0.42) and high = -2.20 cm (95% CI: -3.94, -0.47) (reference = low); unwed mother = 1.75 cm (95% CI: 0.36, 3.14) (reference = married). Overall, the findings suggest that higher childhood socioeconomic position is primarily related to moderately better scores in the most strenuous physical capability measures and hand grip strength among healthy adults in late-middle age., Competing Interests: The authors have declared that no competing interests exist.

Background: Knee osteoarthritis (OA) is a leading cause of musculoskeletal pain and disability globally, and abnormal knee loading is central to disease pathogenesis. Clinical guidelines recommend clinicians provide advice regarding appropriate footwear for people with knee OA, yet there is little research comparing the effects of different footwear on knee OA symptoms. Research suggests that wearing flat flexible shoes is associated with lower knee joint loads compared to stable supportive shoe styles. This two-arm pragmatic, comparative effectiveness randomised controlled trial will compare the effects of daily use of flat flexible shoes and stable supportive shoes on knee OA clinical outcomes, over 6 months., Methods: 164 people with symptomatic medial tibiofemoral OA of moderate to severe radiographic severity (Kellgren and Lawrence Grade 3 & 4) will be recruited from the community. Following baseline assessment, participants will be randomly allocated to receive either i) flat flexible shoes or; ii) stable supportive shoes. Participants will choose two different pairs of shoes from a selection that fulfil the criteria in their allocated shoe class. Limited disclosure will blind participants to group allocation. Participants will be instructed to wear their allocated shoes daily for 6 months (minimum of 6 h/day), after which participants will be reassessed. The primary outcomes are knee pain severity on walking (measured by numerical rating scale) and self-reported physical function (measured by the Western Ontario and McMaster Universities Osteoarthritis Index), assessed at baseline and 6 months. Secondary outcomes include additional measures of knee pain, function, sport and recreation participation and quality-of-life (measured using subscales of the Knee Osteoarthritis Outcome Score), as well as pain at other sites (measured by numerical rating scale), self-reported global ratings of change in pain and physical function (measured by 7-point rating scale), and physical activity levels (measured by Physical Activity Scale for the Elderly)., Discussion: This study will determine whether daily wear of flat flexible shoes improves clinical outcomes in the management of knee OA, compared to stable supportive shoes. Findings will assist clinicians in providing evidence-based advice regarding appropriate footwear for people with knee OA to self-manage symptoms., Trial Registration: Australian New Zealand Clinical Trials Registry reference: ACTRN12617001098325 . Registered 28/07/2017.

Study Design: An in vitro biomechanical study into the effect of rib deconstruction on the flexibility in ovine ribs, using three-point bending., Objective: To examine the feasibility and possible effectiveness of a more conservative costoplasty using an in vitro animal model., Summary of Background Data: Costoplasty remains useful in the treatment of adolescent idiopathic scoliosis, rib hump, and associated chest wall deformities. However, traditional costoplasty increases morbidity and blood loss., Methods: Ribs 2-10 were dissected from four fresh half ovine rib cages. The ribs were randomly allocated to Groups 1 to 4. The ribs underwent deconstruction, 10 mm from the lateral tubercle and 30 mm long, according to their group: Group 1 = control; Group 2 = convex cortical bone removed; Group 3 = convex cortical and cancellous bone removed; Group 4 = all but the ventral cortex is removed. Flexibility was tested by loading the concave side of each rib while fixed at the rib head and equidistant from the center of the resected area. The ribs were deformed at 0.5 mm/s up to a maximum load of 9.99 kg or fracturing. Load was plotted against displacement to find the load/displacement coefficient for each group. Statistical analysis was by an analysis of variance with Tukey's honestly significant difference post hoc testing., Results: The load/displacement coefficients were as follows: Group 1 = 131.93 (±27.52) N/mm, Group 2 = 93.36 (±40.71) N/mm, Group 3 = 88.66 (±25.84) N/mm, and Group 4 = 29.69 (±29.11) N/mm. Group 4 was significantly less stiff than Groups 1, 2, and 3 (p < .01). No ribs in Groups 1, 2, and 4 fractured. Five of 8 ribs in Group 3 fractured during loading., Conclusions: Deconstructing the rib down to the concave side significantly increases the flexibility by approximately 4.5 times. Despite large removal of bone, it retains the ability to withstand 10 kg of load without fracture., (Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Objective: This study examined the associations of body flexibility with carotid arterial remodelling, including intima-media thickness (IMT) and plaque formation in middle-aged men., Methods: The subjects of this cross-sectional study included 1354 Japanese men aged 35-59 years without histories of stroke or cardiac diseases. The arm extensibility test, which can estimate flexibility of the upper extremity (composed of shoulder external rotation and forearm supination), and the sit-and-reach test were performed. Common carotid IMT and plaque formation (≥1.1 mm) were estimated by ultrasound., Results: The proportion of subjects who fully completed the arm extensibility test was 55.0%, and who had plaques in the common carotid artery was 37.8%. IMT was associated with poor arm extensibility (β=-0.073, 95% CI -0.02224 to - 0.00041, P=0.004), while plaque formation was associated with poor sit-and-reach (OR 0.98579, 95% CI 0.97257 to 0.99919, P=0.038) after adjustment by all covariates., Conclusions: This study demonstrated that poor upper extremity and trunk flexibility were associated with characteristics of early onset of atherosclerosis. Furthermore, these associations were independent of covariates such as age, blood pressure, blood lipids glucose levels and abdominal fat accumulation, handgrip strength and lifestyle, including sleeping, drinking, exercise and smoking habits. Poor flexibility may reflect subclinical atherosclerosis in middle-aged men., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Whole-body vibration (WBV) is a neuromuscular training method that has recently received popularity in health and fitness centers, as an additional or substitute method to conventional training and therapy, in order to improve muscle strength and power., Objective: The purpose of this review is to critically observe the effect of WBV training on neuromuscular performance in view of its ability to enhance the muscles strength, power, and flexibility; and also to investigate the influence of the different vibration characteristics (viz., method of application of vibration, frequency, and amplitude) and exercise protocols on the effect of this training., Method: For this review 24 studies or articles were examined, and based on exclusion and inclusion criteria, 5 studies were finally selected; and an attempt was made to uncover the factors influencing the improvement in neuromuscular performance as a result of WBV intervention. During the review, it was considered to include and discuss as many characteristics as possible, such as, knee extension, knee flexion, counter movement jump (CMJ), squat exercise, and jumping height (JH)., Result: Whole-body vibration, along with additional exercise training, has a potential to induce substantial improvement in neuromuscular performance., Conclusion: Whole-body vibration can bring about improvement in muscles strength, power, and flexibility. The main factors associated with the improvement in muscles performance are range of amplitude and frequency, type of vibration and its method of application, training intensity, exercise protocol, and the characteristics of the participants.

Purpose: The aim of this study was to investigate the effects of sling exercise on pain, balance, flexibility, and body form in patients with chronic low back pain (LBP)., Design: The pretest-posttest control group design., Methods: Thirty participants with chronic lumbar pain were divided into three groups (Sling only, Sling + Swing stick flexible bar, and Sling + Ball cushion) and exercised for 12 weeks., Findings: All types of sling exercises provided significant positive effects on pain scale, body balance, flexibility, and body form. In particular, the sling exercise with swing stick flexible bar or ball cushion was more effective on body form, flexibility, and balance than a sling alone., Conclusions: In conclusion, sling exercises over a period of 12 weeks had positive effects on flexibility, balance, pain, and body form in patients with chronic lumbar pain., Clinical Relevance: This study has generated effects of sling exercise, which will assist nursing practitioners in prescribing the beneficial physical rehabilitation for patients with chronic LBP.

Objectives: Previous research has examined lower extremity (LE) musculoskeletal injury (MSI) patterns and risk factors in Special Operations Forces (SOF) trainees, conventional military personnel, and athletes; however, it is unclear if SOF have the same patterns/risk factors. This study aimed to determine the association of musculoskeletal, balance, and physiological characteristics with LE MSI in SOF., Design: Cohort study., Methods: A total of 726 Air Force (N=140), Navy Sea, Air, and Land (N=301), and Special Warfare Combatant Crewmen (N=285) SOF (age=25.72±4.77years, height=178.34±6.63cm, weight=84.28±9.03kg) participated in laboratory testing, including: LE muscular strength and flexibility; balance; body composition; anaerobic power/capacity; and aerobic capacity. Medical charts were reviewed for LE MSI 365days following laboratory testing. Participants were assigned by injury status and laboratory data stratified by tertile. Chi-square statistics were calculated to determine the frequency of LE MSI across tertiles for each characteristic., Results: There was a significant association between LE MSI and: ankle inversion strength (weaker side: Χ(2)=17.703; stronger side: Χ(2)=18.911; p≤0.001); ankle eversion/inversion strength ratio (lower side: Χ(2)=13.456; higher side: Χ(2)=16.885; p≤0.001); hamstring flexibility (less flexible: Χ(2)=19.930; more flexible Χ(2)=15.185; p≤0.001); gastrocnemius-soleus flexibility (less flexible: Χ(2)=7.889, p=0.019); dynamic balance asymmetry (Χ(2)=7.444, p=0.024); Vestibular and Preference ratios (Χ(2)=9.124, p=0.010 and Χ(2)=6.572, p=0.037, respectively); and aerobic capacity (Χ(2)=13.935, p=0.001)., Conclusions: Characteristics associated with LE MSI are unique in SOF. Human performance program initiatives should include efforts to optimize ankle strength and flexibility, maintain moderate hamstring flexibility, expand dynamic balance strategies, and maximize aerobic capacity to reduce LE MSI risk., (Copyright © 2017 Sports Medicine Australia. All rights reserved.)

Clinical Scenario: Increasing the length of the muscle-tendon unit may prevent musculotendinous injury. Various methods have been proposed to increase muscle-tendon flexibility, including self-mobilization using foam rollers or roller massagers, although the effectiveness of these devices is uncertain. This review was conducted to determine if the use of foam rollers or roller massagers to improve hamstrings flexibility is supported by moderate- to high-quality evidence., Clinical Question: Are foam rollers or roller massagers effective for increasing hamstrings flexibility in asymptomatic physically active adults? Summary of Key Findings: The literature was searched for studies on the effects of using foam rollers or roller massagers to increase hamstrings flexibility in asymptomatic physically active adults. Four randomized controlled trials were included; 2 studies provided level 2 or 3 evidence regarding foam rollers and 2 studies provided level 2 or 3 evidence regarding roller massagers. Both roller-massager studies reported increases in hamstrings flexibility after treatment. Data from the foam-roller studies did not demonstrate a statistically significant increase in hamstrings flexibility, but 1 study did demonstrate a strong effect size. Clinical Bottom Line: The reviewed moderate-quality studies support the use of roller massagers but provide limited evidence on the effectiveness of foam rolling to increase hamstrings flexibility in asymptomatic physically active adults. Flexibility gains may be improved by a longer duration of treatment and administration by a trained therapist. Gains appear to decline rapidly postrolling. Neither device has been shown to confer a therapeutic benefit superior to static stretching, and the effectiveness of these devices for preventing injury is unknown. Strength of Recommendation: Grade B evidence supports the use of roller massagers to increase hamstrings flexibility in asymptomatic physically active adults.

Jones, TW, Smith, A, Macnaughton, LS, and French, DN. Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union. J Strength Cond Res 30(12): 3354-3366, 2016-There is limited published research on strength and conditioning (S&C) practices in elite rugby union (RU). Information regarding testing batteries and programme design would provide valuable information to both applied practitioners and researchers investigating the influence of training interventions or preperformance strategies. The aim of this study was to detail the current practices of S&C coaches and sport scientists working in RU. A questionnaire was developed that comprised 7 sections: personal details, physical testing, strength and power development, concurrent training, flexibility development, unique aspects of the programme, and any further relevant information regarding prescribed training programmes. Forty-three (41 men, 2 women; age: 33.1 ± 5.3 years) of 52 (83%) coaches responded to the questionnaire. The majority of practitioners worked with international level and/or professional RU athletes. All respondents believed strength training benefits RU performance and reported that their athletes regularly performed strength training. The clean and back squat were rated the most important prescribed exercises. Forty-one (95%) respondents reported prescribing plyometric exercises and 38 (88%) indicated that periodization strategies were used. Forty-two (98%) practitioners reported conducting physical testing, with body composition being the most commonly tested phenotype. Thirty-three (77%) practitioners indicated that the potential muted strength development associated with concurrent training was considered when programming and 27 (63%) believed that strength before aerobic training was more favorable for strength development than vice versa. This research represents the only published survey to date of S&C practices in northern and southern hemisphere RU.

Study Design: Retrospective cohort study., Objective: To determine treatment outcome with providence brace (PB) and to assess the ability of pretreatment supine lateral bending radiographs (SLBR) in predicting curve progression., Summary of Background Data: Results from treatment with the PB for adolescent idiopathic ccoliosis (AIS) have been inconsistent and further research is needed. The association between flexibility, as determined by pretreatment SLBR, and curve progression has not previously been examined., Methods: All patients treated with the PB from 2006 to 2011 who met Scoliosis Research Society (SRS) bracing criteria were included. Flexibility of the curve was determined based on SLBR and radiographic variables were registered at beginning of treatment and at skeletal maturity (SM) or before surgery. An increase in standing Cobb angle by more than 5 degrees was considered progression. Follow-up SRS-22 scores were compared with a control group with minor AIS. Analysis included multiple linear and logistic regression., Results: A total of 63 patients were included. Mean age was 13.3 years (SD: 1.5) and mean standing Cobb angle was 34° (SD: 5°). Radiographic progression was observed in 43% of patients at SM and surgical rate was 27% and 37% at SM and 2-year follow up, respectively. SRS-22 total scores were similar but the mental health score was significantly better in the control group (P = 0.042). Multiple linear regression analysis showed that decreased flexibility adjusted for age, Cobb angle, and menarchal status was significantly associated with curve progression (P < 0.001). Multiple logistic regression analysis showed that a one percent increase in flexibility was associated with a decrease in risk of curve progression ≥6° (odds ratio = 0.95; 95% confidence interval 0.90-0.98; P = 0.013)., Conclusion: Progression was seen in 43% of AIS patients treated with the PB. Increase in flexibility was independently associated with a decreased risk of progression., Level of Evidence: 3.

Study Design: Retrospective study., Objective: To study the behavior of the unfused thoracic curve in Lenke type 5C during the follow-up and to identify risk factors for its correction loss., Summary of Background Data: Few studies have focused on the spontaneous behaviors of the unfused thoracic curve after selective thoracolumbar or lumbar fusion during the follow-up and the risk factors for spontaneous correction loss., Methods: We retrospectively reviewed 45 patients (41 females and 4 males) with AIS who underwent selective TL/L fusion from 2006 to 2012 in a single institution. The follow-up averaged 36 months (range, 24-105 months). Patients were divided into two groups. Thoracic curves in group A improved or maintained their curve magnitude after spontaneous correction, with a negative or no correction loss during the follow-up. Thoracic curves in group B deteriorated after spontaneous correction with a positive correction loss. Univariate analysis and multivariate analysis were built to identify the risk factors for correction loss of the unfused thoracic curves., Results: The minor thoracic curve was 26° preoperatively. It was corrected to 13° immediately with a spontaneous correction of 48.5%. At final follow-up it was 14° with a correction loss of 1°. Thoracic curves did not deteriorate after spontaneous correction in 23 cases in group A, while 22 cases were identified with thoracic curve progressing in group B. In multivariate analysis, two risk factors were independently associated with thoracic correction loss: higher flexibility and better immediate spontaneous correction rate of thoracic curve., Conclusion: Posterior selective TL/L fusion with pedicle screw constructs is an effective treatment for Lenke 5C AIS patients. Nonstructural thoracic curves with higher flexibility or better immediate correction are more likely to progress during the follow-up and close attentions must be paid to these patients in case of decompensation., Level of Evidence: 4.

Background: This randomized controlled study aims to determine the effect of pilates mat exercises on dynamic and static balance, hamstring flexibility, abdominal muscle activity and endurance in healthy adults., Methods: Female healthy volunteer university students randomly assigned into two groups. Group 1 followed a pilates program for an hour two times a week. Group 2 continued daily activities as control group. Dynamic and static balance were evaluated by Sport Kinesthetic Ability Trainer (KAT) 4000 device. Hamstring flexibility and abdominal endurance were determined by sit-and-reach test, curl-up test respectively. Pressure biofeedback unit (PBU) was used to measure transversus abdominis and lumbar muscle activity. The physical activity of the participants was followed by International Physical Activity Questionnaire-Short Form., Results: Twenty-three subjects in pilates group and 24 control subjects completed the study. In pilates group, statistical significant improvements were observed in curl-up, sit-and-reach test, PBU scores at sixth week (P<0.001), and KAT static and dynamic balance scores (P<0.001), waist circumference (P=0.007) at eighth week. In the comparison between two groups, there were significant improvements in pilates group for sit-and-reach test (P=0.01) and PBU scores (P<0.001) at sixth week, additionally curl-up and static KAT scores progressed in eighth week (P<0.001). No correlation was found between flexibility, endurance, trunk muscle activity and balance parameters., Conclusions: An eight-week pilates training program has been found to have beneficial effect on static balance, flexibility, abdominal muscle endurance, abdominal and lumbar muscle activity. These parameters have no effect on balance.

Study Design: A prospective study., Objective: The aim of this study was to analyze the proximal thoracic (PT) flexibility and its compensatory ability above the "potential UIV.", Summary of Background Data: Shoulder and neck imbalance can be caused by overcorrection of the main thoracic (MT) curve due to inability of PT segment to compensate., Methods: Cervical supine side bending (CSB) radiographs of 100 Lenke 1 and 2 patients were studied. We further stratified Lenke 1 curves into Lenke 1-ve: PT side bending (PTSB) < 15° (n = 33) and Lenke 1+ve: PTSB 15° to 24.9° (n = 37). The right side bending (RSB) and left side bending (LSB) angles were measured (T1-T6). Compensatory ability of the PT segment was analyzed with assumption of a "horizontal UIV" position., Results: From T1 to T6 vertebrae, the RSB angle values showed increasing positive values. The LSB angle, comparing Lenke 1-ve versus 2 and Lenke 1+ve versus 2, showed significant difference at T2 to T6. The LSB angle comparing Lenke 1-ve versus 1+ve achieved significant difference at T5 and T6. In Lenke 2 curves, >80.0% of cases of the PT segment were unable to compensate at T3-T6. In Lenke 1+ve curves, 78.4% were unable to compensate at T6, followed by T5 (75.7%), T4 (73.0%), T3 (59.5%), T2 (27.0%), and T1 (21.6%). In Lenke 1-ve curves, 36.4% of cases were unable to compensate at T6, followed by T5 (45.5%), T4 (45.5%), T3 (30.3%), T2 (21.2%), and T1 (15.2%). A significant difference between Lenke 1-ve and Lenke 1+ve was observed from T3 to T6. The difference between Lenke 1+ve and Lenke 2 curves was significant only at T2., Conclusion: The compensation ability and the flexibility of the PT segments of Lenke 1-ve and Lenke 1+ve curves were different. Lenke 1+ve curves demonstrated similar characteristics to Lenke 2 curves., Level of Evidence: 3.

Study Design: Human cadaveric biomechanical study., Objective: The aim of this study was to evaluate the biomechanics of lumbar motion segments instrumented with the CD HORIZON Spire Z plate system (Spire Z), a posterior supplemental fixation spinous process plate, alone and with additional fixation systems., Summary of Background Data: Plates and pedicle screw/rod and facet screw implants are adjuncts to fusion. The plate limits motion, improving segmental stability and the fusion microenvironment. However, the degree to which the plate contributes to overall stability when used alone or in conjunction with additional instrumentation has not been described., Methods: Standard nondestructive flexibility tests were performed in 7 L2-L5 human cadaveric spines. Spinal stability was determined as mean range of motion (ROM) in flexion/extension, lateral bending, and axial rotation. Paired comparisons were made between five conditions: (1) intact/control; (2) Spire Z; (3) Spire Z with unilateral pedicle screw/rod system (Spire Z+UPS); (4) Spire Z with unilateral facet screw system (Spire Z+UFS); and (5) Spire Z with bilateral facet screw system (Spire Z+BFS). Stiffness and ROM data were compared using one-way analysis of variance, followed by repeated-measures Holm-Šidák tests., Results: Spire Z was most effective in limiting flexion (20% of normal) and extension (24% of normal), but less effective in reducing lateral bending and axial rotation. In lateral bending, Spire Z+BFS and Spire Z+UPS constructs were not significantly different and demonstrated greater ROM reduction compared with Spire Z+UFS and Spire Z (P < 0.001). Spire Z+BFS demonstrated greatest stiffness in axial rotation compared with Spire Z+UPS (P = 0.025), Spire Z+UFS (P = 0.001), and Spire Z (P < 0.001). Spire Z+UPS was not significantly different from Spire Z+UFS (P = 0.21), and superior to Spire Z (P = 0.013)., Conclusion: The Spire Z spinous process plate provides excellent immediate fixation, particularly for flexion and extension. While the hybrid Spire Z+BFS screw construct afforded the greatest stability, Spire Z+UPS demonstrated considerable promise., Level of Evidence: N/A.

Study Design: Cadaveric biomechanical study., Objective: To investigate the kinematic response of a stand-alone lateral lumbar interbody cage compared with supplemental posterior fixation with either facet or pedicle screws after lateral discectomy., Summary of Background Data: Lateral interbody fusion is a promising minimally invasive fixation technique for lumbar interbody arthrodesis. The biomechanical stability of stand-alone cage placement compared with supplemental posterior fixation with either facet or bilateral pedicle screws remains unclear., Methods: A 6-degree of freedom spine simulator was used to test flexibility in 7 human cadaveric specimens. Flexion-extension, lateral-bending, and axial-rotation were tested in the intact condition, followed by destabilization through a lateral discectomy at L2-L3 and L4-L5. Specimens were then reconstructed at both operative segments in the following sequence: (1) lateral interbody cage placement; (2) either Discovery facet screws or the Viper F2 system using a transfacet-pedicular trajectory randomized to L2-L3 or L4-L5; and (3) removal of facet screw fixation followed by placement of bilateral pedicle screw instrumentation. Acute range of motion (ROM) was quantified and analyzed., Results: All 4 reconstruction groups, including stand-alone interbody cage placement, bilateral Discovery facet screws, the Viper F2 system, and bilateral pedicle screw-rod stabilization, resulted in a significant decrease in acute ROM in all loading modes tested (P<0.05). There were no significant differences observed between the 4 instrumentation groups (P>0.05). Although not statistically significant, the Viper F2 system resulted in greatest reduction of acute ROM in both flexion-extension and axial rotation versus all other treatments (P>0.05)., Conclusions: Stand-alone interbody cage placement results in a significant reduction in acute ROM at the operative segment in the absence of posterior supplemental fixation. If added fixation is desired, facet screw placement, including the Viper F2 facet screw system using an integrated compression washer and transfacet-pedicular trajectory, provides similar acute stability to the spinal segment compared with traditional bilateral pedicle screw fixation in the setting of lateral interbody cage deployment.

Object: The effects of obesity on lumbar biomechanics are not fully understood. The aims of this study were to analyze the biomechanical differences between cadaveric L4-5 lumbar spine segments from a large group of nonobese (body mass index [BMI] < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) donors and to determine if there were any radiological differences between spines from nonobese and obese donors using MR imaging., Methods: A total of 168 intact L4-5 spinal segments (87 males and 81 females) were tested using pure-moment loading, simulating flexion-extension, lateral bending, and axial rotation. Axial compression tests were performed on 38 of the specimens. Sex, age, and BMI were analyzed with biomechanical parameters using 1-way ANOVA, Pearson correlation, and multiple regression analyses. MR images were obtained in 12 specimens (8 from obese and 4 from nonobese donors) using a 3-T MR scanner., Results: The segments from the obese male group allowed significantly greater range of motion (ROM) than those from the nonobese male group during axial rotation (p = 0.018), while there was no difference between segments from obese and nonobese females (p = 0.687). There were no differences in ROM between spines from obese and nonobese donors during flexion-extension or lateral bending for either sex. In the nonobese population, the ROM during axial rotation was significantly greater for females than for males (p = 0.009). There was no significant difference between sexes in the obese population (p = 0.892). Axial compressive stiffness was significantly greater for the obese than the nonobese population for both the female-only group and the entire study group (p < 0.01); however, the difference was nonsignificant in the male population (p = 0.304). Correlation analysis confirmed a significant negative correlation between BMI and resistance to deformation during axial compression in the female group (R = -0.65, p = 0.004), with no relationship in the male group (R = 0.03, p = 0.9). There was also a significant negative correlation between ROM during flexion-extension and BMI for the female group (R = -0.38, p = 0.001), with no relationship for the male group (R = 0.06, p = 0.58). Qualitative analysis using MR imaging indicated greater facet degeneration and a greater incidence of disc herniations in the obese group than in the control group., Conclusions: Based on flexibility and compression tests, lumbar spinal segments from obese versus nonobese donors seem to behave differently, biomechanically, during axial rotation and compression. The differences are more pronounced in women. MR imaging suggests that these differences may be due to greater facet degeneration and an increased amount of disc herniation in the spines from obese individuals.

Background: Arthrodesis is optimized when the structural graft occupies most of the surface area within a disc space. The transforaminal corridor inherently limits interbody size., Objective: To evaluate the biomechanical implications of nested interbody spacers (ie, a second curved cage placed behind a first) to increase disc space coverage in transforaminal approaches., Methods: Seven lumbar human cadaveric specimens (L3-S1) underwent nondestructive flexibility and axial compression testing intact and after transforaminal instrumentation at L4-L5. Specimens were tested in 5 conditions: (1) intact, (2) interbody, (3) interbody plus bilateral pedicle screws and rods (PSR), (4) 2 nested interbodies, and (5) 2 nested interbodies plus PSR., Results: Mean range of motion (ROM) with 1 interbody vs 2 nested interbodies, respectively, was: flexion, 101% vs 85%; extension, 97% vs 92%; lateral bending, 127% vs 132%; and axial rotation, 145% vs 154%. One interbody and 2 nested interbodies did not differ significantly by loading mode (P > .10). With PSR, ROM decreased significantly compared with intact, but not between interbody and interbody plus PSR or 2 interbodies plus PSR (P > .80). Mean vertical height during compressive loading (ie, axial compressive stiffness) was significantly different with 2 nested interbodies vs 1 interbody alone (P < .001) (compressive stiffness, 89% of intact vs 67% of intact, respectively)., Conclusion: Inserting a second interbody using a transforaminal approach is anatomically feasible and nearly doubles the disc space covered without affecting ROM. Compressive stiffness significantly increased with 2 nested interbodies, and foraminal height increased. Evaluation of the clinical safety and efficacy of nested interbodies is underway.

Objective: This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue., Methods: Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IPF + pedicle screws (6 anterior, 7 oblique). Pullout tests were then performed on the cage + IPF. Fatigue testing was conducted on the cage + IPF specimens for 30,000 cycles., Results: No ROM differences were observed in any test group between anterior and oblique cage constructs. The greatest reduction in ROM was with supplemental pedicle screw fixation. Peak pullout forces were 637 ± 192 N and 651 ± 127 N for the anterior and oblique implants, respectively. The median cage subsidence was 0.8 mm and 1.4 mm for the anterior and oblique cages, respectively., Conclusions: Anterior and oblique cages similarly reduced ROM in flexibility testing, and the integrated fixation prevented device displacement. Subsidence was minimal during fatigue testing, most of which occurred in the first 2500 cycles.

Thorough pre-testing is critical in assessing the likely in vivo performance of spinal devices prior to clinical use. However, there is a lack of data available concerning the dynamic testing of lumbar (porcine model) total disc replacements in all six axes under preload conditions. The aim of this study was to provide new data comparing porcine lumbar spinal specimen stiffness between the intact state and after the implantation of an unconstrained total disc replacement, in 6 degrees of freedom. The dynamic, stiffness matrix testing of six porcine lumbar isolated disc specimens was completed using triangle waves at a test frequency of 0.1 Hz. An axial preload of 500 N was applied during all testing. Specimens were tested both in the intact condition and after the implantation of the total disc replacement. Sixteen key stiffness terms were identified for the comparison of the intact and total disc replacement specimens, comprising the 6 principal stiffness terms and 10 key off-axis stiffness terms. The total disc replacement specimens were significantly different to the intact specimens in 12 of these key terms including all six principal stiffness terms. The implantation of the total disc replacement resulted in a mean reduction in the principal stiffness terms of 100%, 91%, and 98% in lateral bending, flexion-extension, and axial rotation, respectively. The novel findings of this study have demonstrated that the unconstrained, low-friction total disc replacement does not replicate the stiffness of the intact specimens. It is likely that other low-friction total disc replacements would produce similar results due to stiffness being actively minimised as part of the design of low-friction devices, without the introduction of stiffening elements or mechanisms to more accurately replicate the mechanical properties of the natural intervertebral disc. This study has demonstrated, for the first time, a method for the quantitative comparative mechanical function testing of total disc replacements and provides baseline data for the development of future devices., (© IMechE 2015.)

Background: Self myofascial release (SMR) via a tennis ball to the plantar aspect of the foot is widely used and advocated to increase flexibility and range of movement further along the posterior muscles of a proposed "anatomy train". To date there is no evidence to support the effect of bilateral SMR on the plantar aspect of the feet to increase hamstring and lumbar spine flexibility., Aim: The primary aim was to investigate the immediate effect of a single application of SMR on the plantar aspect of the foot, on hamstring and lumbar spine flexibility. The secondary aim was to evaluate the method and propose improvements in future research., Design: A pilot single blind randomised control trial., Participants: Twenty four healthy volunteers (8 men, 16 women; mean age 28 years ± 11.13)., Method: Participants underwent screening to exclude hypermobility and were randomly allocated to an intervention (SMR) or control group (no therapy). Baseline and post intervention flexibility was assessed by a sit-and-reach test (SRT). A one way between groups analysis of covariance (ANCOVA) was conducted to compare between group outcome SRT measurements. Baseline pre-intervention and control SRT measurements were used as the covariate in the analysis., Results: There was a significant increase (p = 0.03) in the intervention SRT outcome measurements compared to the control group, with a large effect size., Conclusion: An immediate clinical benefit of SMR on the flexibility of the hamstrings and lumbar spine was indicated and suggestions for methodological improvements may inform future research., (Copyright © 2015. Published by Elsevier Ltd.)

The objective of this study was to evaluate the active lifestyle capacity (daily physical activity, strength, flexibility, body composition) of children after the Fontan procedure; hypothesized to be lower than healthy peers. Participants (n = 64, 25 females) were 9.0 ± 1.7 years of age (range 6.0-11.7 years). Fontan completion occurred at 3.3 ± 1.4 years of age (5.7 ± 2.0 years prior). Canadian Health Measures Survey protocols assessed aerobic endurance (paced walking up/down steps), strength (handgrip), flexibility (sit and reach), body composition (body mass index), and daily moderate-to-vigorous physical activity (7-day accelerometry). Difference scores compared participant data to published norms (t tests). Linear regression evaluated age/gender/demographic factor associations. Children after Fontan had strength scores similar (mean difference 1.1 kg) to their peers were less likely to be obese (mean difference of body mass index = 1.1 ± 2.5, p = 0.001) and performed 50 min of moderate-to-vigorous activity (MVPA) per day (12 ± 17 min/day below healthy peers, p < 0.001). Estimated peak endurance (61 % of expected) and flexibility (64 % of expected) were lower than peers (p < 0.001). Almost all (60/63) participants demonstrated the capacity to perform at least 20 min of MVPA per day. Difference from norms was smaller among children younger at Fontan completion (4 ± 2 min/year) and taking antithrombotic medication (7 ± 18 and 22 ± 17 min/day for taking/not taking, respectively). Children after Fontan demonstrate the capacity for the daily physical activity associated with optimal health. They have similar strength and good body composition. We recommend that children after Fontan be counselled that they can successfully participate in healthy, active lifestyles and physically active peer play.

Physical fitness can be defined as a set of attributes that allows the ability to perform physical activity. The attributes or components of fitness were identified by testing large numbers of individuals on physical performance tests (e.g., sit-ups, push-ups, runs, pull-ups, rope climbs, vertical jump, long jumps), and using statistical techniques to find tests that seem to share common performance requirements. These studies identified strength, muscular endurance, cardiorespiratory endurance, coordination, balance, flexibility, and body composition as important fitness components. Military studies have clearly shown that individuals with lower levels of cardiorespiratory endurance or muscular endurance are more likely to be injured and that improving fitness lowers injury risk. Those who are more fit perform activity at a lower percentage of their maximal capability and so can perform the task for a longer period of time, fatigue less rapidly, recover faster, and have greater reserve capacity for subsequent tasks. Fatigue alters movement patterns, putting stress on parts of the body unaccustomed to it, possibly increasing the likelihood of injury. Soldiers should develop and maintain high levels of physical fitness, not only for optimal performance of occupational tasks but also to reduce injury risk., (2015.)

Clinical Scenario: Hamstring tightness is common among physically active individuals. In addition to limiting range of motion and increasing the risk of muscle strain, hamstring tightness contributes to a variety of orthopedic conditions. Therefore, clinicians continue to identify effective methods to increase flexibility. Although hamstring tightness is typically treated with common stretching techniques such as static stretching and proprioceptive neuromuscular facilitation, it has been suggested that whole-body-vibration (WBV) training may improve hamstring flexibility., Clinical Question: Can WBV training, used in isolation or in combination with common stretching protocols or exercise, improve hamstring flexibility in physically active young adults? Summary of Key Findings: Of the included studies, 4 demonstrated statistically significant improvements in hamstring flexibility in the intervention group, and 1 study found minor improvements over time in the intervention group after treatment. Clinical Bottom Line: There is moderate evidence to support the use of WBV training to improve hamstring flexibility in physically active young adults., Strength of Recommendation: There is grade B evidence that WBV training improves hamstring flexibility in physically active adults. The Centre of Evidence Based Medicine recommends a grade of B for level 2 evidence with consistent findings.

The role of mature collagen cross-links, pentosidine (Pen) cross-links in particular, in the micromechanical properties of cancellous bone is unknown. The aim of this study was to examine nonenzymatic glycation effects on tissue stiffness of demineralized and non-demineralized cancellous bone. A total of 60 bone samples were derived from mandibular condyles of six pigs, and assigned to either control or experimental groups. Experimental handling included incubation in phosphate buffered saline alone or with 0.2M ribose at 37°C for 15 days and, in some of the samples, subsequent complete demineralization of the sample surface using 8% EDTA. Before and after experimental handling, bone microarchitecture and tissue mineral density were examined by means of microcomputed tomography. After experimental handling, the collagen content and the number of Pen, hydroxylysylpyridinoline (HP), and lysylpyridinoline (LP) cross-links were estimated using HPLC, and tissue stiffness was assessed by means of nanoindentation. Ribose treatment caused an up to 300-fold increase in the number of Pen cross-links compared to nonribose-incubated controls, but did not affect the number of HP and LP cross-links. This increase in the number of Pen cross-links had no influence on tissue stiffness of both demineralized and nondemineralized bone samples. These findings suggest that Pen cross-links do not play a significant role in bone tissue stiffness., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Study Design: A prospective study; 2-group design., Objective: This study aims to assess the time response of scoliotic spines to orthotic intervention using clinical ultrasound., Summary of Background Data: Patients with moderate adolescent idiopathic scoliosis are generally advised orthotic treatment. However, the time to reach maximum correction after donning spinal orthosis or the time to return to pretreatment curvature after doffing spinal orthosis is not fully understood., Method: Subjects were divided into 2 groups, the don-orthosis group and the doff-orthosis group where the time reaching maximum correction and the time returning to pretreatment curvature were investigated accordingly. To avoid excessive radiation exposure via obtaining repeated radiographs, a validated method of estimating Cobb angle using radiation-free clinical ultrasound was applied at an interval of every 30 minutes up to 180 minutes. The spinal flexibility (estimated from supine radiographs) and body mass index were collected from the subjects for analyses., Result: Nine female patients with adolescent idiopathic scoliosis were recruited. There was no immediate change in the Cobb angles. A change of more than 5° could be observed in both groups only after 30 minutes and maximum change was found at/after 120 minutes. In the doff-orthosis group, the subject with the lowest body mass index took the longest time to increase more than 5° after doffing spinal orthosis. In the don-orthosis group, the subject with the highest body mass index took the longest time to achieve curve correction more than 5°., Conclusion: This investigation demonstrated that there is a time lag between application of spinal orthosis and its effect on scoliotic curvature. This is likely due to the low-stiff and viscoelastic properties of the spine. The clinical relevance of this study is that for patients with scoliosis undergoing orthotic treatment, radiograph should not be obtained within 2 hours of putting on or taking off spinal orthosis because it may not show the maximum effect., Level of Evidence: 4.

Prediction of intracellular metabolic fluxes based on optimal biomass assumption is a well-known computational approach. While there has been a significant emphasis on the optimality, cellular flexibility, the co-occurrence of suboptimal flux distributions in a microbial population, has hardly been considered in the related computational methods. We have implemented a flexibility-incorporated optimization framework to calculate intracellular fluxes based on a few extracellular measurement constraints. Taking into account slightly suboptimal flux distributions together with a dual-optimality framework (maximization of the growth rate followed by the minimization of the total enzyme amount) we were able to show the positive effect of incorporating flexibility and minimal enzyme consumption on the better prediction of intracellular fluxes of central carbon metabolism of two microorganisms: E. coli and S. cerevisiae.

Purpose: Characterization of the biomechanical properties of the human eye has a number of potential utilities. One novel purpose is to provide the basis for development of suitable tissue-mimicking material. The purpose of this study was to determine the indentation and needle insertion characteristics on human eye globes and tissue strips., Methods: An indenter assessed the elastic response of human eye globes and tissue strips under increasing compressive loads. Needle insertion determined the force (N) needed to penetrate various areas of the eye wall., Results: The results demonstrated that globes underwent slightly greater indentation at the midline than at the central cornea, and corneal strips indented twofold more than scleral strips, although neither difference was significant (P=0.400 and P=0.100, respectively). Significant differences were observed among various areas of needle insertion (P<0.001). Needle insertion through the anterior sclera (adjacent to the limbus) and posterior sclera (adjacent to the optic nerve) required the greatest amount of force (0.954 and 1.005 N, respectively). The force required to penetrate the central cornea (0.518 N) was significantly lower than all other areas except the midline sclera (0.700 N) CONCLUSION: These data form the basis for further research into the development of a tissue-mimicking human eye construct with potential utility as a model for use in ophthalmology research and surgical teaching.

Objective: This study aimed to investigate the biomechanical qualities of the perichondrium and cartilage, and to determine the strength of the septal cartilage against bending forces., Study Design: This paper describes an experimental cadaver study., Materials and Methods: The nasal septal cartilages of 14 fresh cadavers (8 hours postmortem) were excised from the cadavers and cut into two strips: one with the perichondrium (group A) and one without perichondrium (group B). A bending test was then performed on the strips., Results: The deflection of group A strips was larger than the deflection of group B strips. Flexural strength was also larger in group A strips compared to group B strips. The average modulus of elasticity was 122% higher in group A compared to group B. All conducted tests revealed statistically significant differences between groups., Conclusion: This study objectively shows that the perichondrium provides the cartilage with a 25% bending strength.

Background Context: The soft tissues of the spine exhibit sensitivity to strain-rate and temperature, yet current knowledge of spine biomechanics is derived from cadaveric testing conducted at room temperature at very slow, quasi-static rates., Purpose: The primary objective of this study was to characterize the change in segmental flexibility of cadaveric lumbar spine segments with respect to multiple loading rates within the range of physiologic motion by using specimens at body or room temperature. The secondary objective was to develop a predictive model of spine flexibility across the voluntary range of loading rates., Study Design: This in vitro study examines rate- and temperature-dependent viscoelasticity of the human lumbar cadaveric spine., Methods: Repeated flexibility tests were performed on 21 lumbar function spinal units (FSUs) in flexion-extension with the use of 11 distinct voluntary loading rates at body or room temperature. Furthermore, six lumbar FSUs were loaded in axial rotation, flexion-extension, and lateral bending at both body and room temperature via a stepwise, quasi-static loading protocol. All FSUs were also loaded using a control loading test with a continuous-speed loading-rate of 1-deg/sec. The viscoelastic torque-rotation response for each spinal segment was recorded. A predictive model was developed to accurately estimate spine segment flexibility at any voluntary loading rate based on measured flexibility at a single loading rate., Results: Stepwise loading exhibited the greatest segmental range of motion (ROM) in all loading directions. As loading rate increased, segmental ROM decreased, whereas segmental stiffness and hysteresis both increased; however, the neutral zone remained constant. Continuous-speed tests showed that segmental stiffness and hysteresis are dependent variables to ROM at voluntary loading rates in flexion-extension. To predict the torque-rotation response at different loading rates, the model requires knowledge of the segmental flexibility at a single rate and specified temperature, and a scaling parameter. A Bland-Altman analysis showed high coefficients of determination for the predictive model., Conclusions: The present work demonstrates significant changes in spine segment flexibility as a result of loading rate and testing temperature. Loading rate effects can be accounted for using the predictive model, which accurately estimated ROM, neutral zone, stiffness, and hysteresis within the range of voluntary motion., (Copyright © 2014 Elsevier Inc. All rights reserved.)

This study investigated the effects of peristaltic pulse dynamic compression (PPDC) on range-of-motion (ROM) changes in forward splits. Serious stretching usually involves discomfort and large time investments. Tissue structural changes and stretch tolerance have heretofore been considered the primary mechanisms of enhanced ROM. The PPDC treatment was computer controlled. Circumferential and segmented inflation pressures were induced by feet to hip leggings. Nine subjects, experienced in stretching and a forward split position, volunteered. The subjects were familiarized with the protocol and randomly assigned to an initial condition: experimental (PPDC), or control (CONT). The study involved a crossover design. Second conditions were tested within 1-5 days. All tests were 2 trials of right and left forward splits. Split flexibility was assessed by measuring the height of the anterior superior iliac spine of the rear leg from the floor. Pelvic posture was controlled by rear leg position. The PPDC treatment was 15 minutes of seated PPDC. The control condition was the same except that leggings were not inflated. Pressures of 5 cells in the leggings were set at factory defaults, 70 mm Hg sequentially. Difference score results indicated statistically significant (p ≤ 0.05) differences by condition and the condition by leg interaction. The rapid acute changes in ROM (PPDC: right 25.3%, left 33.3%; CONT: right 12.2%, left 1.0%) support the premise that changes in ROM were dependent on mechanisms other than tissue structural changes and/or stretch tolerance. PPDC provides a means of rapidly enhancing acute ROM requiring less discomfort and time.

Unlabelled: Loss of muscle strength, flexibility, and balance are strong predictors of falls in the elderly., Objectives: The goal of this research was to investigate the effectiveness of a 10-week, strength-based exercise program delivered by Extension professionals., Methods: Matched pair t tests were used to compare differences in five measures of fitness collected from 808 participants (mean age = 65.4 years) at the start and finish of the exercise program., Results: Following programming, participants significantly improved strength, flexibility, and balance., Discussion: Results indicate that an evidence-based program can be translated into a community Extension program that is able to improve the fitness level of seniors.

Stochastic winter weather events are predicted to increase in occurrence and amplitude at northern latitudes and organisms are expected to cope through phenotypic flexibility. Small avian species wintering in these environments show acclimatization where basal metabolic rate (BMR) and maximal thermogenic capacity (MSUM) are typically elevated. However, little is known on intra-seasonal variation in metabolic performance and on how population trends truly reflect individual flexibility. Here we report intra-seasonal variation in metabolic parameters measured at the population and individual levels in black-capped chickadees (Poecileatricapillus). Results confirmed that population patterns indeed reflect flexibility at the individual level. They showed the expected increase in BMR (6%) and MSUM (34%) in winter relative to summer but also, and most importantly, that these parameters changed differently through time. BMR began its seasonal increase in November, while MSUM had already achieved more than 20% of its inter-seasonal increase by October, and declined to its starting level by March, while MSUM remained high. Although both parameters co-vary on a yearly scale, this mismatch in the timing of variation in winter BMR and MSUM likely reflects different constraints acting on different physiological components and therefore suggests a lack of functional link between these parameters.

Purpose: We investigated the extent of corneal displacement and factors associated with the measurement of IOP during the early and late phases of noncontact tonometry., Methods: One eye in each of 61 healthy volunteers was studied. In each case, the cornea was photographed in profile using a high-speed camera during noncontact tonometry. The extent of displacement at the corneal center, and at the midperipheral corneal areas at 13.2 and 30.0 ms after the application of an air puff was recorded. For each measurement point, multiple regression analyses were performed against age, sex, axial length, corneal curvature, IOP, and central corneal thickness (CCT) to determine the independent predictors of corneal displacement. Multiple comparison tests were used to determine whether the displacement differences were associated with age or sex., Results: Our results showed that the factors most associated with corneal displacement were the IOP (P < 0.001) and CCT (P = 0.02) at the corneal center at 13.2 ms, the CCT (P = 0.041) at the corneal midperiphery at 13.2 ms, age (P < 0.01) at the corneal center at 30.0 ms, and age (P = 0.04) and IOP (P = 0.04) at the corneal midperiphery at 30.0 ms. Young females had the smallest amounts of corneal displacement at all measurement points, and elderly females had largest amounts of displacement at the late phase of tonometry., Conclusions: The amount of corneal displacement is affected by an individual's IOP, age, and CCT. Our findings indicated that the corneas of females may be more susceptible to aging than those of males.

Purpose: To investigate the biomechanical and refractive behaviors of normal and keratoconic corneas based on three-dimensional anisotropic hyperelastic corneal models with two layers., Methods: Based on an anisotropic hyperelastic formula, the finite element method was employed to develop normal and keratoconic corneal models in which the fiber orientations and the biomechanical differences between corneal layers were taken into account. The displacements for normal and keratoconic corneal models were studied, as well as changes in corneal refractive power with intraocular pressure (IOP)., Results: There were different displacements for keratoconic and normal corneas. Positive correlations were found in the keratoconic cornea between IOP and apical displacement, as well as between IOP and corneal refractive power. Under normal IOP, both the corneal shape and refractive power map were affected by the stiffness distributions of the corneal layers., Conclusions: Finite element analysis can be used to demonstrate the biomechanical and refractive behavior of a cornea with keratoconus. From a biomechanical viewpoint, the displacement changes seen under normal IOP were due to the decreased stiffness in the keratoconic corneal tissue and local thinning disorders. Thus, the curvature and corneal refractive power map will be abnormal in keratoconus., (Copyright 2013, SLACK Incorporated.)

Quadriceps muscle strains frequently occur in sports that require repetitive kicking and sprinting, and are common in football in its different forms around the world. This paper is a review of aetiology, mechanism of injury and the natural history of rectus femoris injury. Investigating the mechanism and risk factors for rectus femoris muscle injury aims to allow the development of a framework for future initiatives to prevent quadriceps injury in football players.

The epidermis of digital pads in geckos comprises superficial microornamentation from the oberhautchen layer that form long setae allowing these lizards to climb vertical surfaces. The beta-layer is reduced in pad lamellae but persists up to the apical free margin. Setae are made of different proteins including keratin-associated beta-proteins, formerly indicated as beta-keratins. In order to identify specific setal proteins the present ultrastructural study on geckos pad lamellae analyzes the immunolocalization of three beta-proteins previously found in the epidermis and adhesive setae of the green anolis. A protein rich in glycine but poor in cysteine (HgG5-like) is absent or masked in gecko pad lamellae. Another protein rich in glycine and cysteine (HgGC3-like) is weakly present in setae, oberhautchen and beta-layer. A glycine and cysteine medium rich beta-protein (HgGC10-like) is present in the lower part of the beta-layer but is absent in the oberhautchen, setae, and mesos layer. The latter two proteins may form intermolecular bonds that contribute to the flexibility of the corneous material sustaining the setae. The pliable alpha-layer present beneath the thin beta-layer and in the hinge region of the pad lamellae also contains HgGC10-like proteins. Based on the possibility that some HgGC3-like or other cys-rich beta-proteins are charged in the setae it is suggested that their charges influence the mechanism of adhesion increasing the induction of dipoles on the substrate and enhancing attractive van der Waals forces., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: The purpose of this study is to evaluate in-vitro the immediate effect of corneal collagen cross-linking (CXL) on corneal hydration and stiffness., Methods: Forty-two corneal buttons from freshly enucleated porcine eyes were immersed in riboflavin 0.1% in dextran 20% dilution for 3 h in order for their hydration to reach equilibrium. Corneal buttons where divided into two groups; the first group was stored in dark conditions while the other group was irradiated with UV radiation (370 nm) for 30 min to simulate CXL according to the clinically applied protocol. After irradiation, all corneas were immersed in dextran 20% solution for 3 additional hours. Subsequently, each button underwent weighing, thickness measurement, and was mounted in a special device for the measurement of force versus deformation by compression. Finally, all corneal buttons were dehydrated for 48 h in a desiccating oven set at 62 °C and weighed again to obtain their dry mass. Hydration (%) of each button was calculated., Results: Mean corneal hydration in the irradiated and the non-irradiated group of corneas was 69.8 and 72.2%, respectively (p < 0.001). Differences in thickness and compressibility were not statistically significant. Thickness and hydration were positively correlated (Pearson's r = 0.714, p < 0.001)., Conclusions: CXL causes corneal dehydration that can be detected immediately after the procedure. This phenomenon may contribute to increased mechanical stiffness of the cornea. A change in stiffness by means of compressibility could not be detected in porcine corneas.

The factors regulating the body's ability to switch from fat to carbohydrate oxidation in response to fuel availability changes, or metabolic flexibility (MF), are currently intensively investigated in the context of metabolic diseases. Although numerous metabolic diseases are associated with sedentary behaviors and metabolic inflexibility, the effect of habitual physical activity level (PAL) on MF regulation is surprisingly poorly known. We investigated how PAL affects MF in cross-sectional and interventional studies. MF was assessed in 44 subjects: normal-weight and overweight sedentary men submitted to 2 mo of exercise at current recommendations, normal-weight active men submitted to 1 mo of reduced PAL and normal-weight women submitted to 1 mo of bed rest, with or without exercise. MF was evaluated, before and after interventions, following two standard meals as the relationship between individual mathematical variances in insulin and nonprotein respiratory quotient (NPRQ) daily kinetics. Daily NPRQ and insulin variances differed according to habitual PAL (P = 0.002 and P = 0.009, respectively); active subjects had higher variances in NPRQ for lower variances in insulin than sedentary subjects, indicating a better MF. Detraining increased insulin variance (P = 0.009) and decreased NPRQ variance (P = 0.003), while training tended to have opposite effects. Insulin and NPRQ variances were negatively related along the PAL continuum (R(2) = 0.70, P < 0.001). Variance in NPRQ was also positively related to PAL (R(2) = 0.52, P < 0.001). By assessing MF with mathematical surrogates in conditions of daily pattern in meal's intake, we showed that habitual PAL is associated with MF status, and that MF is modulated by changes in PAL.

In competitive human swimming the submerged dolphin kick stroke (underwater undulatory swimming) is utilized after dives and turns. The optimal dolphin kick has a balance between minimizing drag and maximizing thrust while also minimizing the physical exertion required of the swimmer. In this study laser scans of athletes are used to provide realistic swimmer geometries in a single anatomical pose. These are rigged and animated to closely match side-on video footage. Smoothed Particle Hydrodynamics (SPH) fluid simulations are performed to evaluate variants of this swimming stroke technique. This computational approach provides full temporal and spatial information about the flow moving around the deforming swimmer model. The effects of changes in ankle flexibility and stroke frequency are investigated through a parametric study. The results suggest that the net streamwise force on the swimmer is relatively insensitive to ankle flexibility but is strongly dependent on kick frequency., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)