Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815–0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.

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Background: Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand. Methods: Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (%MVIC). Differences between conditions for RMS%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p ≤ 0.05; Bonferroni adjusted α = 0.008). Results: PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles. Conclusion: Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.

Frailty assessment is recommended before elective transcatheter aortic valve implantation (TAVI) to determine post-interventional prognosis. Several studies have investigated frailty in TAVI-patients using numerous assessments; however, it remains unclear which is the most appropriate tool for clinical practice. Therefore, we evaluate which frailty assessment is mainly used and meaningful for ≤30-day and ≥1-year prognosis in TAVI patients. Randomized controlled or observational studies (prospective/retrospective) investigating all-cause mortality in older (≥70 years) TAVI patients were identified (PubMed; May 2020). In total, 79 studies investigating frailty with 49 different assessments were included. As single markers of frailty, mostly gait speed (23 studies) and serum albumin (16 studies) were used. Higher risk of 1-year mortality was predicted by slower gait speed (highest Hazard Ratios (HR): 14.71; 95% confidence interval (CI) 6.50–33.30) and lower serum albumin level (highest HR: 3.12; 95% CI 1.80–5.42). Composite indices (five items; seven studies) were associated with 30-day (highest Odds Ratio (OR): 15.30; 95% CI 2.71–86.10) and 1-year mortality (highest OR: 2.75; 95% CI 1.55–4.87). In conclusion, single markers of frailty, in particular gait speed, were widely used to predict 1-year mortality. Composite indices were appropriate, as well as a comprehensive assessment of frailty.

BackgroundSensorimotor exercises (SE) are evident to enhance neuromuscular activity of the trunk muscles (TM). However, it is unclear if an additional unexpected perturbation leads to higher muscular activity and therefore enhances training efficacy.ObjectiveTo analyse effects of additional unexpected perturbations on trunk neuromuscular activation pattern during SE.DesignCross-sectional design.SettingUniversity Outpatient Clinic, Sports Medicine Centre.ParticipantsTen healthy, normal active participants (5 m/5 f; 29±2 yrs; 177±7 cm, 74±12 kg) were included.Assessment of Risk FactorsAll participants were prepared with a bilateral 12-lead trunk EMG (Mm. rectus abdominis (RA), external obliquus (EO), internal obliquus (IO), latissimus dorsi (LD), thoracic (UES) and lumbar erector spinae (LES)). Warm-up on an isokinetic dynamometer (extension/flexion; 30 rep; 60°sec) was followed by maximum voluntary isometric contraction measurements (MVC, 5 sec). Next, a (right-armed) side plank on stable surface (SP; 30 sec) and 2 different instable conditions were randomly assigned (SP plus pad under the elbow (SPP), SPP plus perturbation (SPP+P)).Main Outcome MeasurementsRoot mean square (RMS) normalized to MVC (%MVC) was calculated during the whole exercise. Muscles were grouped to ventral right/left (VR;VL=mean of RA, IO, EO), and dorsal right/left (DR;DL=mean of LD, UES, LES). Differences between conditions were calculated for muscle groups, Ventral:Dorsal (V:D) and Side-Right/Side-Left ratio (SR;SL) (repeated-measures ANOVA; α=0.05).ResultsSPP+P showed highest EMG-RMS (e.g,VR: 81±9%; DR: 55±12%) for all muscle groups except DL with significant differences (p<0.05) between conditions SP and SPP+P in VR, VL and DR muscle groups. No differences were found between SPP (e.g.,VR: 71±11%) and SPP+P (e.g.,VR: 81±9%)(p>0.05). Statistically significant higher V:D ratios was found in SPP+P compared to SP (p<0.05). SR:SL ratio did not show any differences (p>0.05).ConclusionsThe use of additional perturbations during core stability training is superior to enhance trunk neuromuscular activity and should be implemented into sensorimotor exercises addressing the trunk.