Work-relief ratios and imbalances of load application in sport climbing: another link to overuse-induced injuries?

An imbalanced load application of the upper extremity may contribute to overuse-induced injuries of the fingers. Thus, the present study evaluated load-application symmetry between the right and the left hand and its work-relief ratios (WRR) depending on climbing ability and pre-exhaustion level. Twenty-eight sport climbers (age: 29 ± 8 years; body mass index: 22 ± 2 kg/m(2); years of climbing: 10 ± 6; climbing level: 6+ UIAA to 9 UIAA) were assigned to a group of recreational (≤8-UIAA, n = 14) or a group of ambitious (≥8 UIAA, n = 14) climbers. Blood lactate and perceived exertion level were recorded at the end of the climbing attempt. Load application and WRR were derived from video analysis separately for the left and the right hand. Differences in load-application time between the left (47 ± 4%) and the right (53 ± 4%) hand (P < 0.001) were observed. Irrespective of side differences, the overall WRR was 5:1. Increasing climbing level leads to a more symmetric load application (r = -0.42, P < 0.03). Differences of lactate concentration and exertion level were found between the pre- and the non-pre-exhausted group. Depending on climbing ability and exhaustion level, load application for the dominant hand (right) prevails. Further longitudinal studies should focus on imbalanced load application and overuse-induced climbing injuries.

[Severe and moderate haemophilia under prophylactic replacement treatment--maximal knee extensor and flexor torque of children and adolescents]. / Schwere und mittelschwere Hämophilie unter prophylaktischer Substitutionstherapie. Maximale Drehmomente der Knieextensoren und Knieflexoren bei Kindern und Jugendlichen.

UNLABELLED: Due to its influence on haemophilic arthropathy, the evaluation of knee extensor (K(Ext)) and flexor (K(Flex)) torques plays an important role in the preventive and rehabilitative context of haemophilia. Thus, the present study aimed at investigating maximal static torque (M(Max)) of K(Ext) and K(Flex). 14 boys with haemophilia (8 severe, 6 moderate; age: 11.7 ± 2.8 years; prophylactic treatment > 5 years) and 14 healthy carefully pair-matched controls (age: 11.5 ± 2.7 years) were separately measured for the left and right leg for M(Max). Furthermore, the ratio K(Flex)/K(Ext )was calculated and the joint situation assessed using the Haemophilia Joint Health Score. RESULTS: No significant group-effect was observed for M(Max) of the K(Ext) and K(Flex) as well as for the ratio K(Flex)/K(Ext) (p>0.05). Despite significant higher joint scores in haemophilic children compared to their healthy controls (p<0.01), patients merely showed minor joint impairments. CONCLUSION: Children and adolescents with severe and moderate haemophilia under prophylactic replacement treatment with a good joint status showed comparable maximal strength performance of relevant knee muscles compared to their healthy peers.

[Altered hip muscle activation in patients with chronic non-specific low back pain]. / Veränderte Beckenmuskelaktivierung bei Patienten mit chronischem nichtspezifischem Rückenschmerz.

BACKGROUND: The aim of this study was to examine postural control in patients with chronic non-specific low back pain (CNRS). Furthermore the influence of visual information (eyes open versus eyes closed) was analyzed. MATERIAL AND METHODS: A total of 8 patients with CNRS and 12 healthy control subjects were examined. Surface electromyography (SEMG) recordings were made from 5 trunk and 5 lower limb muscles as well as one hip muscle during application of distal lateral perturbation. RESULTS: Healthy controls (mean ± standard deviation: 96.42±64.77 µV) showed a significantly higher maximum amplitude of the gluteus medius muscle in comparison to patients with CNRS (56.29±39.63 µV). Furthermore activation of several lower limb muscles was found to be dependent on visual information. CONCLUSION: Patients showed an altered reflex response of the gluteus medius muscle which could be associated with reduced hip stability.

[Maximal isometric strength measures of the quadriceps muscles. Feasibility and reliability in patients with haemophilia]. / Isometrische Maximalkraftmessungen der Quadrizepsmuskulatur. Durchführbarkeit und Reliabilität bei Patienten mit Hämophilie.

UNLABELLED: The quadriceps femoris muscle (QF) plays an important role in locomotion. However, assessing the total number of attempts to evaluate the maximal isometric strength (Fmaxiso) regarding reliability and feasibility remain less characterised. PATIENTS, METHODS: 28 patients with haemophilia (H) (26 severe, 2 moderate) and 27 healthy controls (C) matched for age (H: 44 ± 11, C: 42 ± 12) and anthropometric data were measured separately for the left and right leg for Fmaxiso of QF using m3 diagnos (SCHNELL®). We repeated the Fmaxiso measures after 48 h in 14 H and 13 C. RESULTS: The system m3 diagnos showed strong reliability (ICC = 1.0; SEM = 0.0; CA = 1.0). H and C demonstrated significant differences in Fmaxiso (H r = 153 Nm, l = 164 Nm; K r= 289 Nm, l = 280 Nm; p ≤ 0.001). Additionally, H and C revealed significant differences between the 1st and 3rd to 6th attempts. No differences were observed between the 3rd, 4th, 5th and 6th attempts. CONCLUSION: Both groups showed high test-retest-reliability of Fmaxiso (ICC/SEM: H l = 0.98/7.1 r = 0.99/4.9; K l = 0.69/11.3 r = 0.95/5.8). Starting from the 3rd attempt, reliable measurements of the Fmaxiso in patients suffering from severe haemophilia are feasible.

Does prolonged cycling of moderate intensity affect immune cell function?

BACKGROUND: Prolonged exercise may induce temporary immunosuppression with a presumed increased susceptibility for infection. However, there are only few data on immune cell function after prolonged cycling at moderate intensities typical for road cycling training sessions. METHODS: The present study examined the influence on immune cell function of 4 h of cycling at a constant intensity of 70% of the individual anaerobic threshold. Interleukin-6 (IL-6) and C-reactive protein (CRP), leukocyte and lymphocyte populations, activities of natural killer (NK), neutrophils, and monocytes were examined before and after exercise, and also on a control day without exercise. RESULTS: Cycling for 4 h induced a moderate acute phase response with increases in IL-6 from 1.0 (SD 0.5) before to 9.6 (5.6) pg/ml 1 h after exercise and CRP from 0.5 (SD 0.4) before to 1.8 (1.3) mg/l 1 day after exercise. Although absolute numbers of circulating NK cells, monocytes, and neutrophils increased during exercise, on a per cell basis NK cell activity, neutrophil and monocyte phagocytosis, and monocyte oxidative burst did not significantly change after exercise. However, a minor effect over time for neutrophil oxidative burst was noted, tending to decrease after exercise. CONCLUSIONS: Prolonged cycling at moderate intensities does not seem to seriously alter the function of cells of the first line of defence. Therefore, the influence of a single typical road cycling training session on the immune system is only moderate and appears to be safe from an immunological point of view.

Oral premedication with low dose midazolam modifies the immunological stress reaction after the setting of retrobulbar anaesthesia.

BACKGROUND/AIMS: An acute immunological stress reaction was previously reported to occur after the painful setting of retrobulbar anaesthesia before intraocular surgery. This study was conducted to find out whether an oral low dose premedication with midazolam would modify the immunological stress reaction. METHODS: 32 patients undergoing intraocular surgery using retrobulbar anaesthesia were included in a randomised, double blind trial. They received premedication with either 3.75 mg midazolam or placebo 30 minutes before the retrobulbar injection. Counts of leucocyte subpopulations, cardiovascular, and psychometric parameters were measured repetitively before and after the retrobulbar injection. RESULTS: The numbers of leucocytes increased significantly in the placebo group after the setting of retrobulbar anaesthesia (before retrobulbar injection: 6687 (SD 1025) cells x10(6)/l; after injection: 7067 (1022) cells x10(6)/l, p=0.0009) caused by rising numbers of neutrophils (before injection: 4111 (1063) cells x10(6)/l; after injection: 4352 (1147) cells x10(6)/l, p=0.0007) and natural killer cells (before injection: 290 (84) cell x10(6)/l; after injection 354 (133) cells x10(6)/l, p=0.003). There was no significant increase in total leucocytes (before injection: 5997 (1288) cells x10(6)/l; after injection: 6189 (1215) cells x10(6)/l) or in any leucocyte subpopulation in the midazolam group. A significant rise in systolic blood pressure occurred in the placebo group, but not in the midazolam group. CONCLUSION: A low dose premedication with midazolam attenuates the immunological and cardiovascular stress reactions occurring with retrobulbar anaesthesia.

Physical training increases isometric muscular strength and proprioceptive performance in haemophilic subjects.

Sufficient muscular strength and proprioception lessen the risk of joint damage, however, both are impaired in haemophilic subjects. The aim of the study was to investigate proprioceptive performance and isometric muscular strength before and after a specialized training in haemophilic subjects (H) compared with two groups of control subjects (C). Nine subjects with severe haemophilia A, and eight 'active' C (AC) without haemophilia took part in a physical training programme over a 6-month period. Eleven 'passive' C (PC) were requested to avoid any additional training during this period. Proprioceptive performance and isometric strength were determined before and after the training programme. The maximal isometric muscular strength in the legs, bilaterally measured by knee extensor (and leg press) was increased (P < 0.05) by 34% (29%) after training in the H and by 20% (28%) in the AC groups while remaining unchanged in the PC group. The performance in one-leg-stand tests after training was increased (P < 0.05) in the H and AC groups. An improvement of angle reproduction of 20 degrees and 40 degrees (P < 0.05) in the H compared with the PC groups was seen in the tests. Quantitative sensory testing by the tuning fork showed an increase (P < 0.05) in performance of both H and AC groups. The results of the present study confirm that specific sports therapy focused on proprioceptive function and accompanied by gentle strength training with low resistance and 20-25 repetitions is able to increase proprioceptive performance and muscular strength with a minimal stress to the joints. It is strongly recommended that specialized sports therapy be included as an integral component of the complete treatment regimen of haemophilic subjects.

Metabolic profile of 4 h cycling in the field with varying amounts of carbohydrate supply.

Several laboratory studies have demonstrated a performance-enhancing effect of carbohydrate (CHO) supplementations during endurance sessions of long duration. However, the transferability of these results to real training and competition circumstances has not been conclusively shown. Therefore, we tried to test the influence of graded CHO substitution on substrate utilization and selected physiological parameters under standardized but practically orientated field conditions. Fourteen endurance-trained male subjects [mean (SD): 25 (5) years, 72 (9) kg, .VO(2max) 67 (6) ml.min(-1).kg(-1), individual anaerobic threshold (IAT) 269 (30) W] after a stepwise increasing pre-test had to perform three 4-h endurance rides on their own bicycles with simultaneous spiroergometry: constant workload 70% IAT (monitoring by SRM-System). Before and during exercise, solutions without (0%), with 6% or 12% CHO were administered double-blindly and in randomized order (total volume: 50 ml.kg(-1)). After cessation of exercise, significant differences between 0% and both CHO concentrations were detected for blood glucose (GLU; 75 mg dl(-1) for 0% vs 101 mg dl(-1) for 6% vs 115 mg dl(-1) for 12%; P<0.001) and respiratory exchange ratio (0.84 vs 0.88 vs 0.90; P<0.01; correlation to GLU: r=0.46, P<0.05). Free fatty acids (0.19 vs 0.16 vs 0.10 mmol l(-1)) and glycerol (0.41 vs 0.22 vs 0.12 mmol l(-1)) were significantly different between the endurance trials in a dose-dependent manner (both P<0.001). Lactate concentration ( P=0.42) and heart rate ( P=0.12) had no significant influence from CHO substitution. We conclude that CHO substitution during 4-h endurance training inhibits lipolysis in a dose-dependent manner and enhances aerobic glycolysis. This proves that earlier laboratory findings can be replicated under field conditions using modern portable equipment.

Mobilization and oxidative burst of neutrophils are influenced by carbohydrate supplementation during prolonged cycling in humans.

Prolonged, strenuous exercise may lead to suppressive effects on the immune system, which might be responsible for a greater susceptibility to opportunistic infections. The aim of this study was to examine the influence of carbohydrate substitution (CHS) during prolonged, strenuous exercise on neutrophil granulocytes and their oxidative burst (intracellular oxidation of dihydrorhodamine(123) to rhodamine(123) after induction by formylized 1-methionyl-1-leucyl-1-phenylalanin) using flow cytometry. In three trials different concentrations of CHS (placebo compared to 6% and 12% CHS; 50 ml.kg(-1)) were given randomly to 14 endurance trained cyclists [mean (SD) age 25 (5) years, maximal oxygen uptake 67 (6) ml.min(-1).kg(-1)] cycling for 4 h in a steady state at 70% of their individual anaerobic threshold. Blood samples were taken before, immediately after cessation, 1 h and 19 h after exercise. A significant rise in neutrophil counts was observed immediately after cessation and 1 h after exercise with a return to normal rest values 19 h after exercise for all three conditions ( P<0.001). The relative proportions of rhodamine(123)+ neutrophils were significantly diminished in all three conditions 1 h after exercise ( P<0.01), while the mean fluorescence intensity was lowest in the placebo trial and differed significantly to the 12% CHS trial ( P=0.024) and almost significantly to the 6% CHS trial ( P=0.052). In conclusion, these data suggest a beneficial effect of CHS on the neutrophil oxidative burst and a possible attenuation of the susceptibility to infections, presumably due to the reduction of metabolic stress in prolonged, strenuous exercise.