Long term evolution of soft tissue response in the fingers of high-level sport climbers: A cross-sectional 10 Year follow-up study

BackgroundSport climbing induces physiological changes in the body of high-level climbers. In 2012, our study group demonstrated adaptions of elite climbers’ soft tissues with thicker A2/A4-pulleys, flexor tendons and palmar plates compared to non-climbers.ObjectivesTo assess these adaptations over time we examined all 31 (follow up 100%) climbers that participated in that baseline study again using ultrasonography after a follow-up of 10 years.Main findings(1) In climbers, a significant increase in A2 and A4-pulley and flexor tendon thickness over the last 10 years was observed (p < 0.001), while PIP&DIP palmar plate thickness remained unchanged (p > 0.05); (2) at 10-years follow-up, all soft tissue thickness parameters (incl. palmar plates) were still significantly larger in climbers than in age-matched controls (p < 0.05); (3) as for the association with anthropometrics and climbing performance/experience, a significant association of the current climber's soft tissue thickness could only be found between palmar plate and reached climbing level(p = 0.032) as well as climber's body weight(p = 0.004).ConclusionAn accumulation of repetitive climbing-related stress to the fingers of elite sport climbers over the career induces mechano-adaptation of the A2/A4-pulleys, flexor tendons and palmar plates. At later stages, there is a further significant increase in flexor tendon and pulley thickness, but not for palmar plate thickness.     

Analysis of stress fractures in athletes based on our clinical experience

AIM: To analyze stress fractures in athletes based on experience from our sports medicine clinic.METHODS: We investigated the association between stress fractures and age, sex, sports level, sports activity, and skeletal site in athletes seen at our sports medicine clinic between September 1991 and April 2009. Stress fractures of the pars interarticularis were excluded from this analysis.RESULTS: During this period (18 years and 8 mo), 14276 patients (9215 males and 5061 females) consulted our clinic because of sports-related injuries, and 263 patients (1.8%) [171 males (1.9%) and 92 females (1.8%)] sustained stress fractures. The average age of the patients with stress fractures was 20.2 years (range 10-46 years); 112 patients (42.6%) were 15-19 years of age and 90 (34.2%) were 20-24 years of age. Altogether, 90 patients (34.2%) were active at a high recreational level and 173 (65.8%) at a competitive level. The highest proportion of stress fractures was seen in basketball athletes (21.3%), followed by baseball (13.7%), track and field (11.4%), rowing (9.5%), soccer (8.4%), aerobics (5.3%), and classical ballet (4.9%). The most common sites of stress fractures in these patients were the tibia (44.1%), followed by the rib (14.1%), metatarsal bone (12.9%), ulnar olecranon (8.7%) and pelvis (8.4%). The sites of the stress fractures varied from sport to sport. The ulnar olecranon was the most common stress fracture site in baseball players, and the rib was the most common in rowers. Basketball and classical ballet athletes predominantly sustained stress fractures of the tibia and metatarsal bone. Track and field and soccer athletes predominantly sustained stress fractures of the tibia and pubic bone. Aerobics athletes predominantly sustained stress fractures of the tibia. Middle and long distance female runners who sustained multiple stress fractures had the female athlete triad.CONCLUSION: The results of this analysis showed that stress fractures were seen in high-level young athletes, with similar proportions for males and females, and that particular sports were associated with specific sites for stress fractures. Middle and long distance female runners who suffered from multiple stress fractures had the female athlete triad.     

Reliability of a portable fixed frame dynamometry system used to test lower limb strength in elite Australian Football League players

ObjectivesDeficits in strength of lower limb musculature have been associated with increased injury risk in a variety of athletic populations. As medical and performance staff seek to better understand the association between hip and knee strength measures and injury risk, measurement tools with high reliability and utility are required to profile and manage athletes effectively. The purpose of this study was to investigate the test-retest reliability of a portable fixed frame dynamometry system used to assess hip and knee strength of an elite Australian Football League team.DesignCase series.MethodsMaximum voluntary isometric strength of the hip abductors, hip adductors and knee flexors of 41 elite male Australian Football League footballers (mean age = 23.7 ± 4.1 years, height = 189.2 ± 7.0 cm, weight = 88.6 ± 8.4 kg) were tested during preseason training. Tests were performed one week apart on the same training day of a standard preseason week.ResultsTest-retest reliability was very high for left hip adduction (ICC 0.958), right hip adduction (ICC 0.955), left hip abduction (ICC 0.957), right hip abduction (ICC 0.945), left knee flexion (ICC 0.927) and right knee flexion (ICC 0.923). Furthermore, standard errors of measurement in per cent (SEM%) ranged from 3.21 to 5.03%, and minimal detectable change (MDC) from 3.93 to 6.65 kg for the different hip and thigh strength measures, making it possible to determine small changes in strength at the individual level.ConclusionsThis study demonstrated very high reliability when testing maximal voluntary isometric hip and knee strength using a portable fixed dynamometry system (KangaTech) in an elite male Australian Football League setting.     

Biomechanical quantification of deadbug bridging performance in competitive alpine skiers: Reliability,reference values,and associations with skiing performance and back overuse complaints

Objectives(1) To study the reliability of quantifying rear-chain stabilization capacity during deadbug bridging (DBB), (2) to provide reference values for competitive alpine skiers, and (3) to study associations with age, anthropometrics, maturation, skiing performance and back overuse complaints.DesignCross-sectional.SettingBiomechanical field experiment including questionnaires.Participants12 healthy subjects (reliability experiment); 133 skiers of the U16 category and 38 of the elite category (main experiment).Main outcome measuresDBB performance was quantified using 3D motion capture as the maximum amplitude of the relative vertical displacement of two pelvis markers (DBB_displacement). Additionally, in U16 skiers, age, anthropometrics, maturation, skiing performance, and back overuse complaints were assessed.ResultsThe reliability experiment revealed an ICC(3,1) and 95% CI of 0.81 [0.61, 0.93]. Within-subject SEM was 3.89 mm [3.16 mm, 5.12 mm]. Depending on sex and category, medians of DBB_displacement in skiers ranged between 29 mm and 45 mm. DBB_displacement differed between elite and U16 skiers (p < 0.001), but not between sexes. In U16 skiers, DBB_displacement was independent of age, anthropometrics, and biological maturation, however, associated with skiing performance and back overuse complaints (p < 0.05).ConclusionThe proposed approach may be considered an adequate method to quantify athletes’ rear-chain stabilization capacity.     

The effects of visual cognitive tasks on landing stability and lower extremity injury risk in high-level soccer players

BackgroundVisual cognition plays a pivotal role in sports. It is widely recognized that there is an intriguing coupling that they could affect each other through interaction between visual cognition and motor control, but few studies linked the effects of visual cognitive tasks on landing stability to postural control and injury risk.Research questionWhether visual cognitive tasks affect the landing stability and lower limb injury risk of professional soccer players?MethodsThe current study used a three-dimensional Multiple Object Tracking (MOT) task to simulate visual cognitive difficulties experienced in soccer matches. Fifteen male high-level soccer athletes (height: 181.43 ± 7.36 cm, weight: 75.37 ± 10.67 kg, training years: 10.07 ± 2.98 yr) from our school team were recruited and completed a landing action from a high platform with and without MOT tasks. Vicon infrared high-speed motion capture system and three-dimensional force measuring platform were used to collect various outcomes simultaneously.ResultsThe Time to Stabilization (TTS) during landing was significantly prolonged, while the Medial-Lateral Stability Index (MLSI), Anterior-Posterior Stability (APSI), Dynamic Postural Index Stability Index (DPSI), the trajectory lengths, and envelope area of COP during landing were also increased during MOT dual-task.DiscussionThe decline of these indicators reflected the deterioration in postural stability and greater requirements for maintaining balance which could increase the risk of injury in soccer athletes. We advocate that adequate visual attention and visual information processing might play critical roles in maintaining dynamic balance through the supraspinal neural network.     

Haematological and iron-related parameters of male endurance and strength trained athletes

Summary To obtain more information on the effects of long-lasting endurance and strength training on the constituents of the blood, several haematological and iron-related parameters were measured at rest in 39 male athletes from the Polish team who participated in the Olympics in Seoul in 1988. The athletes were divided into two groups: endurance-trained subjects (group E, cyclists, canoeists and rowers; n=22) and strength-trained subjects (group S, wrestlers and judo; n=17). The control group was composed of untrained male subjects (n=48). Blood samples were taken from an antecubital vein with the subject at rest for determinations of haemoglobin concentration ([Hb]), packed cell volume (PCV), erythrocyte (RBC) and reticulocyte count, plasma free haemoglobin concentration, haptoglobin concentration, serum iron, transferrin concentration and ferritin concentrations ([Ferr]); red blood cells were used for estimation of glutamato-oxalate transaminase (GOT) activity and free erythrocyte protoporphyrin concentration ([FEP]). The mean [Hb], PVC, RBC measured in the E athletes were significantly lower than in the control group but were comparable to those obtained in the S athletes. There were no significantly differences in the haematological indices [mean corpuscular volume (MCV), mean copuscular haemoglobin and mean corpuscular haemoglobin concentration] between the groups of athletes and the control group. A significant increase in reticulocytosis and GOT activity was observed in the endurance-trained athletes. No impairment of erythropoiesis was observed as indicated by several sensitive markers of haemoglobin formation (FEP, MCV and inspection of blood smears) in the athletes. The athletes from group E had mean serum [Ferr] below 50 g·l^–1 which was significantly lower than [Ferr] in the serum of subjects from the control group and the strength-trained athletes. The results of the present investigation showed that some haematological parameters and the iron status of the endurance athletes differed from the untrained subjects as well as the strength-trained athletes.     

Loss of Bone Mineral Density in Women Athletes During Aging

Total and regional bone mineral density (BMD) by dual-energy-X-ray absorptiometry (DXA) and bone turnover were tested in 50 highly trained women athletes and 21 sedentary control women (18–69 years; BMI < 25 kg/m²). VO_2max (ml · kg⁻¹· min⁻¹) and lean tissue mass (DXA) were significantly higher in the athletes versus controls (both P < 0.0001). Total body BMD did not decline significantly with age in the athletes whereas lumbar spine (L₂–L₄) BMD approached statistical significance (r =−0.26; P= 0.07). Significant losses of the femoral neck (r =− 0.42), Ward's triangle (r =−0.53), and greater trochanter BMD (r =−0.33; all P < 0.05) occurred with age in the athletes. In the athletes, total body BMD, L₂–L₄ BMD, and BMD of all sites of the femur were associated with lean tissue mass (r = 0.32 to r = 0.57, all P < 0.05) and VO_2max (r = 0.29 to r = 0.48, all P < 0.05). Femoral neck and greater trochanter BMD were higher in the athletes than in controls (both P < 0.05) and lumbar spine and Ward's triangle BMD approached statistical significance (both P= 0.07). Bone turnover was assessed by serum bone-specific alkaline phosphatase (B-ALP), urinary deoxypyridinoline cross-links (Dpd), and urinary aminoterminal cross-linked telopeptides (NTX). There were no relationships between B-ALP or Dpd with age whereas NTX increased with age (r = 0.46, P < 0.05) in the entire group. Levels of B-ALP and NTX were negatively associated with total body, L₂–L₄, femoral neck, Ward's triangle, and greater trochanter BMD (P < 0.05). B-ALP and Dpd were not significantly different between athletes and controls whereas NTX was lower in the athletes than in controls (P < 0.001). The high levels of physical activity observed in women athletes increase aerobic capacity and improve muscle mass but are not sufficient to prevent the loss of bone with aging. Received: 28 November 1997 / Accepted: 8 April 1998     

A critical review of chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) has been described in the literature as a neurodegenerative disease with: (i) localized neuronal and glial accumulations of phosphorylated tau (p-tau) involving perivascular areas of the cerebral cortex, sulcal depths, and with a preference for neurons within superficial cortical laminae; (ii) multifocal axonal varicosities and axonal loss involving deep cortex and subcortical white matter; (iii) relative absence of beta-amyloid deposits; (iv) TDP-43 immunoreactive inclusions and neurites; and (v) broad and diverse clinical features. Some of the pathological findings reported in the literature may be encountered with age and other neurodegenerative diseases. However, the focality of the p-tau cortical findings in particular, and the regional distribution, are believed to be unique to CTE. The described clinical features in recent cases are very similar to how depression manifests in middle-aged men and with frontotemporal dementia as the disease progresses. It has not been established that the described tau pathology, especially in small amounts, can cause complex changes in behavior such as depression, substance abuse, suicidality, personality changes, or cognitive impairment. Future studies will help determine the extent to which the neuropathology is causally related to the diverse clinical features.     

A critical review on sleep assessment methodologies in athletic populations: factors to be considered

A growing body of research focus on athletes' sleep in order to investigate the effects of sleep in sports performance and recovery or the prevalence of sleep disorders in athletes. At the same time, several sleep monitoring tools have been developed and used in athletic populations for fulfilling these purposes. This review aimed to provide critical assessment to the most used by athletes' methodological approaches and compared them with the gold standard approach. Advantages and disadvantages of the various sleep monitoring tools were critically discussed. Literature related to aspects of athletes' sleep was reviewed. From the shortlisted studies, several factors that seem to affect sleep in athletes were identified using objective methods such as polysomnography/electroencephalography and actigraphy. These factors were associated to sleep (eg such as sleep environment, familiarization procedures and napping) and daily habits (eg nutrition, fluid consumption, alcohol and caffeine intake, tobacco use). The selected studies that evaluated sleep objectively were screened according the reporting rates of these variables. The majority of the screened studies were found to underreport these variables. Practical issues were addressed and recommendations about reporting sleep-related factors were made in order to improve studies’ quality assessment and allow for more robust comparisons between studies.