Prediction of Rowing Functional Threshold Power Using Body Mass, Blood Lactate and GxT Peak Power Data.

Functional Threshold Power (FTP) is a validated index of a maximal quasi steady-state cycling intensity. The central component of the FTP test is a maximal 20-min time-trial effort. A model to predict FTP from a cycling graded exercise test (m-FTP) was published that estimated FTP without the requirement of the exhaustive 20-min time-trial. The predictive model (m-FTP) was trained (developed to find the best combination of weights and bias) on a homogenous group of highly-trained cyclists and triathletes. This investigation appraised the external validity of the m-FTP model vis-à-vis the alternate modality of rowing. The reported m-FTP equation purports to be sensitive to both changing levels of fitness, and exercise capacity. To assess this claim, eighteen (7 female, 11 male) heterogeneously-conditioned rowers were recruited from regional rowing clubs. The first rowing test was a 3-min graded incremental test with a 1-min break between increments. The second test was a rowing adapted FTP test. There were no significant differences between rowing FTP (r-FTP) and m-FTP (230 ± 64 versus 233 ± 60 W, respectively, F = 1.13, P = 0.80). Computed Bland-Altman 95% LoA between r-FTP and m-FTP were (-18 W to + 15 W), sy.x was 7 W, and 95 %CI of regression were 0.97 to 0.99. The r-FTP equation was demonstrated to be effective in predicting a rowers 20-min maximum power; further appraisal of the physiological response to rowing for 60-min at the corresponding calculated FTP requires investigation.

Prediction of Functional Threshold Power from Graded Exercise Test Data in Highly-Trained Individuals.

The purpose of the current investigation was to derive an equation that could predict Functional Threshold Power (FTP) from Graded Exercise Test (GxT) data. The FTP test has been demonstrated to represent the highest cycling power output that can be maintained in a quasi-steady state for 60-min. Previous investigations to determine a comparable marker derived from a Graded Exercise test have had limited success to date. Consequently, the current study aimed to predict FTP from GxT data to provide an additional index of cycling performance. FTP has been reported to provide an insight not provided by a GxT and, in addition, does not require a formal exercise testing facility. The study design facilitated a deliberate and transparent sequence of statistical decisions, resolved in part from the perspective of exercise physiology. Seventy triathletes (male n=50, female n=20) completed cycling GxT and FTP tests in sequential order. Collected data (power output, blood lactate indices, VO2peak, body mass) were analysed using stepwise regression to identify the key parameters for predicting FTP, and confirmed using a Leave One Out (LOO) cross-validation. As a consequence of wittingly including some likely transiently highly correlated parameters on the basis of a physiological argument, the model's function is limited to predicting FTP. This investigation concluded the model (FTP = -6.62 + 0.32 FBLC-4 + 0.42 BM + 0.46 Pmax) was the prediction model of choice.

A Comparison of Physiological Response to Incremental Testing on Stationary and Dynamic Rowing Ergometers.

PURPOSE: The purpose of the current study was to compare responses to graded exercise testing (GXT) on 2 popular commercial rowing ergometers. METHODS: A cohort of 23 subelite male rowers (age 20 [2] y, height 1.88 [0.06] m, body mass 82.0 [8.8] kg) performed a GXT on both stationary (Concept2 [C2]) and dynamic (RowPerfect3 [RP3]) rowing ergometers. Physiological responses including oxygen consumption (VO2), heart rate (HR), blood lactate concentration (BLa), stroke rate (SR), and minute ventilation (VE) were recorded. BLa data were plotted graphically and anaerobic threshold was identified using the Dmax method. Workload, HR, and VO2 at Dmax were interpolated. Physiological responses at maximal exercise and at Dmax were compared, along with response across a discrete range of submaximal workloads. RESULTS: At maximal exercise, no significant differences in HR, VO2, or BLa were observed (P > .05); however, VEpeak was significantly higher during RP3 tests (T = 2.943, P < .05). No significant differences in HR, VO2, or BLa at Dmax were observed (P > .05). When comparing across submaximal workloads, HR was significantly higher with the RP3 at 2 distinct workloads (210 and 240 W; P < .05), while SR was higher during RP3 testing at all workloads (F = 56.7, P < .05). When SR was fixed as a covariate, the effect of ergometer on HR response was not significant. A significant workload by ergometer interaction effect was observed for SR with higher data recorded on the RP3 (F = 3.48, P < .01). Levels of agreement for GXT-derived measures of anaerobic threshold (Dmax) were deemed unacceptable. CONCLUSIONS: These results indicate that while some differences in HR and VE response were observed between ergometers, these differences were a result of SR alterations between ergometer type. While no differences in response at Dmax were observed, the poor levels of agreement between ergometers suggests that prescription of GXT-derived threshold for training should ideally be specific to the rowing ergometer upon which the test was performed.

Do Critical and Functional Threshold Powers Equate in Highly-Trained Athletes?

The purpose of this investigation was to determine whether Critical Power (CP) and Functional Threshold Power (FTP) can be used interchangeably for a highly-trained group of cyclists and triathletes. CP was ascertained using multiple fixed load trials and FTP determined from a single cycling trial. Three different models for the determination of CP were initially addressed, one hyperbolic (Hmodel) and two linear (Jmodel and Imodel). The Jmodel was identified as most appropriate for a comparison with FTP. The Jmodel and FTP were not found to be interchangeable as ANOVA detected significant differences (282 ± 53 vs. 266 ± 55 W, p < 0.001) between these indices and the associated Bland-Altman 95% limits of agreement exceeded those set a priori. As the Jmodel was found to be consistently higher than FTP, a correction factor was posited to anticipate CP from FTP in this homogenous group of athletes using the mean bias (16 W). An alternate method for assessing CP trial intensities using Dmax as a proxy for ventilatory threshold is also proposed. The concept of both CP and FTP representing a maximal metabolic steady-state requires further investigation as the mechanical power at CP was significantly greater than at FTP.

Bilateral reversed palmaris longus muscle: a case report and systematic literature review.

PURPOSE: We present a case of a bilateral reversed palmaris longus muscle and a systematic review of the literature on this anatomical variation. METHODS: Routine dissection of a 90-year-old male cadaver revealed a rare bilateral reversed palmaris longus. This was documented photographically, and length and relation to anatomical landmarks were recorded. This finding stimulated a systematic review of the literature on the reversed palmaris longus variation, from which measurements were collated and statistical analysis performed to determine the prevalence, average length, relationship to side and sex, and to discuss its clinical and evolutionary implications. RESULTS: The average length of the muscle belly and tendon of reversed palmaris longus was 135 mm and 126 mm, respectively. Statistical analysis revealed no disparity in presentation due to sex and side; however, bilateral reversed palmaris longus has only been reported in males. A high proportion (70.8%) of reversed palmaris longus were discovered in the right upper limb compared to the left. CONCLUSION: Variations in palmaris longus are purported to be as a result of phylogenetic regression. Clinically, patients with this variant may present with pain or swelling of the distal forearm, often as a result of intense physical exertion related to occupation or sport. Clinicians should be aware of this muscle variant as its presence could lead to confusion during tendon allograft harvesting procedures in reconstructive and tendon grafting surgery.

Is the FTP Test a Reliable, Reproducible and Functional Assessment Tool in Highly-Trained Athletes?

The aim of the current study was to assess reliability of the Functional Threshold Power test (FTP) and the corresponding intensity sustainable for 1-hour in a "quasi-steady state". Highly-trained athletes (n = 19) completed four non-randomized tests over successive weeks on a Wattbike; a 3-min incremental test (GxT) to exhaustion, two 20-min FTP tests and a 60-min test at computed FTP (cFTP). Power at cFTP was calculated by reducing 20-min FTP data by 5% and was compared with power at Dmax and lactate threshold (TLac). Ventilatory and blood lactate (BLa) responses to cFTP were measured to determine whether cFTP was quasi-steady state. Agreement between consecutive FTP tests was quantified using a Bland-Altman plot with 95% limits of agreement (95% LoA) set at ± 20 W. Satisfactory agreement between FTP tests was detected (95% LoA = +13 and -17 W, bias +2 W). The 60-min effort at cFTP was successfully completed by 17 participants, and BLa and ventilatory data at cFTP were classified as quasi-steady state. A 5% increase in power above cFTP destabilized BLa data (p < 0.05) and prompted VO2 to increase to peak GxT rates. The FTP test is therefore deemed representative of the uppermost power a highly-trained athlete can maintain in a quasi-steady state for 60-min. Agreement between repeated 20-min FTP tests was judged acceptable.

A biomechanical assessment of ergometer task specificity in elite flatwater kayakers.

The current study compared EMG, stroke force and 2D kinematics during on-ergometer and on-water kayaking. Male elite flatwater kayakers (n = 10) performed matched exercise protocols consisting of 3 min bouts at heart and stroke rates equivalent to 85% of VO2peak (assessed by prior graded incremental test). EMG data were recorded from Anterior Deltoid (AD), Triceps Brachii (TB), Latissimus Dorsi (LD) and Vastus Lateralis (VL) via wireless telemetry. Video data recorded at 50 Hz with audio triggers pre- and post-exercise facilitated synchronisation of EMG and kinematic variables. Force data were recorded via strain gauge arrays on paddle and ergometer shafts. EMG data were root mean squared (20ms window), temporally and amplitude normalised, and averaged over 10 consecutive cycles. In addition, overall muscle activity was quantified via iEMG and discrete stroke force and kinematic variables computed. Significantly greater TB and LD mean iEMG activity were recorded on-water (239 ± 15 vs. 179 ± 10 µV. s, p < 0.01 and 158 ± 12 vs. 137 ± 14 µV.s, p < 0.05, respectively), while significantly greater AD activity was recorded on-ergometer (494 ± 66 vs. 340 ± 35 µV.s, p < 0.01). Time to vertical shaft position occurred significantly earlier on-ergometer (p < 0.05). Analysis of stroke force data and EMG revealed that increased AD activity was concurrent with increased external forces applied to the paddle shaft at discrete phases of the on-ergometer stroke cycle. These external forces were associated with the ergometer loading mechanism and were not observed on- water. The current results contradict a previous published hypothesis on shoulder muscle recruitment during on-water kayaking. Key pointsWhen exercising at fixed heart and stroke rates, biomechanical differences exist between onergometer and on-water kayaking.Ergometer kayaking results in significantly greater Anterior Deltoid activity but significantly lower Triceps Brachii and Latissimus Dorsi activity, compared with on-water kayaking.The altered muscle recruitment patterns observed on-ergometer are most likely a result of additional forces associated with the ergometer loading mechanism, acting upon the paddle shaft.

A cadaveric study of complications associated with the subxiphoid and transthoracic approaches to emergency pericardiocentesis.

OBJECTIVES: The aim of this cadaveric study was to compare three commonly used approaches for emergency pericardiocentesis and to determine the safest approach. METHODS: Thirteen cadavers were injected at three sites with three different coloured dyes, one for each of the three different recommended approaches. The approaches used were (1) ATIP: anterior transthoracic in the fifth left intercostal space (Advanced Cardiac Life Support protocol), (2) SXP1: immediately subxiphoid and (3) SXP2: subxiphoid approach 1.5 cm inferior to SXP1 (Advanced Trauma Life Support protocol). The needles were left in the chest cavity to confirm their course on the way into the pericardial sac. Once the chest plate was removed, the location of the needle and the presence of dye enabled the identification of structures damaged and cavities entered by the needle. The associated complications from the three approaches were then recorded and compared. RESULTS: The anterior transthoracic intercostal pericardiocentesis approach to pericardiocentesis (2/39) and an immediately subxiphoid approach SXP1 (1/39) produced fewer potential complications than SXP2 (4/39). CONCLUSIONS: The SXP1 approach appeared to be the safest, followed by anterior transthoracic intercostal pericardiocentesis. The SXP2 approach caused the highest amount of complications, resulting from the needle entering the abdominal cavity. The presence of intra-abdominal pathology and the possibility of post-mortem changes in the position of the diaphragm, however, might have been a causative factor in this finding.

Relationship of the common peroneal nerve and its branches to the head and neck of the fibula.

The common peroneal nerve (CPN) lies on the neck of the fibula, which forms the floor of the so-called 'fibular tunnel.' The tunnel entrance is a musculo-aponeurotic arch derived from the soleus and peroneus longus muscles and it is here that the CPN is commonly compressed in cases of peroneal nerve palsy. This study aims to define the relationship of the CPN and its branches to the apex of the head of the fibula and to the tunnel, with special regard to possible sites of entrapment. The distances from the apex of the fibula to the opening of the fibular tunnel, the CPN bifurcation, and the exit point of the deep peroneal nerve (DPN) from the tunnel, were measured in 30 legs to ascertain possible sites of entrapment. The angle that the CPN subtended with the long axis of the fibula was measured to gauge the range of positions of the CPN at the neck of the fibula. An unyielding musculo-aponeurotic fibular arch at the entrance to the fibular tunnel was confirmed in all specimens. The DPN exited through a crescentic opening in the anterior intermuscular septum in all cases and no DPN branches were found in the lateral compartment in any specimen. The mean (+/-SD) distance from the apex of the head of the fibula to the opening of the fibular tunnel was 3.2 +/- 1.0 cm, to the CPN bifurcation was 3.8 +/- 0.9 cm, and to the DPN exit point was 7.0 +/- 1.5 cm. The mean angle subtended anteriorly from the long axis of the fibula by the CPN was 18.9 +/- 9.0 degrees. We recommend further study of the mean distances and reference angle in relation to fibular landmarks, for use in possible minimally invasive surgical procedures to decompress the fibular tunnel.

Chronic exertional compartment syndrome: the controversial "fifth" compartment of the leg.

BACKGROUND: The existence of a "fifth" compartment in the leg capable of developing distinct chronic exertional compartment syndrome remains a subject of controversy. HYPOTHESIS: Specific pressure recordings and dissection will confirm or disprove the existence of a fifth compartment. STUDY DESIGN: Empirical anatomic study. METHODS: Radiopaque dye was injected directly into the tibialis posterior muscle of 25 embalmed cadaveric legs while intracompartmental pressure was monitored. Radiographs demonstrated dye distribution, and dissection-documented fascial and epimysial layers. RESULTS: Evidence was found that the fibular origin of the flexor digitorum longus muscle, when present, could create subcompartments within the deep posterior compartment. The nature of this attachment varied from being absent, to small (<8 cm), to extensive (>8 cm). The attachment partially covered the tibialis posterior muscle in the majority of the 14 legs that developed high pressures, and it was limited or absent in the 11 legs that did not. Radiographs demonstrated that the dye was confined to the tibialis posterior muscle in four legs. CONCLUSIONS: No consistent fifth compartment exists in the leg; however, subcompartments within the deep posterior compartment created by the fibular origin of the flexor digitorum longus muscle may develop pressures congruent with chronic exertional compartment syndrome. CLINICAL RELEVANCE: Potential deep posterior subcompartments demand accurate pressure investigation. A modified technique to decompress the entire deep posterior compartment, including the tibialis posterior muscle, is necessary for successful treatment of chronic exertional compartment syndrome.