Countermovement Jump and Drop Jump Performances Are Related to Grand Jeté Leap Performance in Dancers With Different Skill Levels.

ABSTRACT: Blanco, P, Nimphius, S, Seitz, LB, Spiteri, T, and Haff, GG. Countermovement jump and drop jump performances are related to grand jeté leap performance in dancers with different skill levels. J Strength Cond Res 35(12): 3386-3393, 2021-Thirty-five classical ballet dancers were chosen to investigate relationships between the grand jeté leap, countermovement jump (CMJ), and drop jump (DJ) and establish whether the magnitude of the relationship between these tests differed across 3 skill levels. Subjects (male: n = 11 and female: n = 24) were divided into 3 groups: novice (n = 12; age: 16.6 ± 1.5 years; height: 1.7 ± 0.1 m; body mass: 58.0 ± 13.0 kg), semiprofessional (n = 13; age: 20.0 ± 1.6 years; height: 1.7 ± 0.1 m; body mass: 64.1 ± 10.5 kg), and professional (n = 10; age: 23.8 ± 3.5 years; height: 1.8 ± 1.2 m; body mass: 63.3 ± 14.7 kg). Grand jeté leap height, followed by CMJ and DJ vertical displacement, was assessed. Significant relationships were found between the grand jeté, CMJ (r = 0.77, p = 0.001) and DJ (r = 0.76, p = 0.001). After a Fisher's r-z transformation, professional dancers and novice dancers showed greater r-value differences in CMJ (r2 - r1 = 0.27) compared with novice (r2 - r1 = 0.17) and semiprofessional dancers (r2 - r1 = 0.11), indicating larger strength of CMJ to grand jeté relationship in professionals. The grand jeté leap showed large to very large correlations with CMJ and DJ within groups. These common performance tests were determined to be practical and efficient methods for assessing the jumping ability of dancers. As dance skill increased, larger correlations were observed, suggesting that dancers with superior ballet skills may be more likely to use their underpinning physical capacities to jump higher within the context of ballet-specific jumping.

Evidence for a New Compact Symmetric Fission Mode in Light Thorium Isotopes.

Taking benefit of the R3B/SOFIA setup to measure the mass and the nuclear charge of both fission fragments in coincidence with the total prompt-neutron multiplicity, the scission configurations are inferred along the thorium chain, from the asymmetric fission in the heavier isotopes to the symmetric fission in the neutron-deficient thorium. Against all expectations, the symmetric scission in the light thorium isotopes shows a compact configuration, which is in total contrast to what is known in the fission of the heavier thorium isotopes and heavier actinides. This new main symmetric scission mode is characterized by a significant drop in deformation energy of the fission fragments of about 19 MeV, compared to the well-known symmetric scission in the uranium-plutonium region.

Spontaneous sensations reveal distorted body perception in complex regional pain syndrome (CRPS).

Distortions of body representation have been reported in Complex Regional Pain Syndrome (CRPS). The perception of sensations arising without external triggers (spontaneous sensations or SPS) was assessed here as a means of investigating distortions of body representation and awareness in CRPS. To avoid confounds between CRPS symptoms and SPS, lower-limb CRPS patients were included, whereas SPS were tested on the hands. Patients and controls were required to focus on their hands and to report the spatial and qualitative characteristics of SPS arising there. We found an ipsilateral decrease in the perception of thermal, pain-related and surface/mechanical SPS, as well as in the number of SPS-sensitive areas. The latter finding was predicted by decreased body awareness as assessed through questionnaires. A bilateral decrease in the perception of paresis-like SPS was also observed. Finally, the ipsilateral spatial distribution of SPS frequency and intensity underwent a shift from the fingers towards the lower parts of the palm. CRPS is likely to distort patient's body perception and awareness of the entire half-body ipsilateral to the affected limb, and even of both sides. Such disturbances are not manifested solely as a decrease in sensitivity, but sometimes as shifts in the spatial distribution of sensitivity.

Clavicular osteotomy in complicated revision of total shoulder arthroplasty: indications, surgical technique, and outcomes.

PURPOSE: Adequate exposure in revision of total shoulder arthroplasty (TSA) is important for optimal prosthesis placement and functional results. A clavicular osteotomy in difficult cases of revision TSA is a useful surgical technique that increases the superior exposure area, provides safer dissection, minimizes damage to the anterior deltoid muscle, improves glenoid access, and allows for superior dislocation of the humeral component. There is a paucity of literature analyzing the clavicular osteotomy during challenging cases of revision TSA. The aims of this study were to describe the application, surgical technique, and outcomes of revision TSA with a clavicular osteotomy. METHODS: This was a retrospective study of consecutive patients who underwent revision TSA with a clavicle osteotomy at a single institution (2004-2016). A curved longitudinal clavicular osteotomy is created parallel to the origin of the anterior deltoid muscle. This allows for lateral reflection of the osteotomy and anterior deltoid muscle to significantly increase superior exposure and reduce damage to remaining deltoid muscle fibres. Osteotomy closure is simple with four or five Nice knot osteosutures. The Constant-Murley score and osteotomy healing were assessed at every follow-up. All complications were reviewed. RESULTS: Forty patients who had a mean age of 63.8 years (range 37-87) at time of surgery and mean follow-up duration of 34 months (range 12-88) were analyzed. Pre-operative Constant-Murley scores improved significantly from 32 ± 19.0 to 58 ± 15.0 (p < 0.001) at one year and 65 ± 13.1 (p < 0.001) at two years. Primary osteotomy healing and callus formation were evident in 95% of cases by three months. Five patients developed post-operative complications (13%) related to the clavicular osteotomy: three mid-diaphyseal clavicular fractures sustained after trauma (8%), one clavicular stress fracture (3%), and case of one loosening (3%). Three patients (8%) required surgical revision of the osteotomy (two internal fixation and one revision osteosuturing). No neurovascular injuries or scapular fractures were encountered. CONCLUSION: A curved longitudinal clavicular osteotomy is beneficial in difficult revision TSA and is another tool in the arsenal of experienced shoulder surgeons who manage these challenging cases. This surgical technique increases glenoid exposure, facilitates superior dislocation of the humeral component, minimizes anterior deltoid damage, and reduces the risk of neurovascular injuries. All clavicular complications occurred within four months prior to osteotomy union, with many sustained due to trauma. However, patients who developed a complication had comparable shoulder function as those without.

Variable, but not free-weight, resistance back squat exercise potentiates jump performance following a comprehensive task-specific warm-up.

Studies examining acute, high-speed movement performance enhancement following intense muscular contractions (frequently called "post-activation potentiation"; PAP) often impose a limited warm-up, compromizing external validity. In the present study, the effects on countermovement vertical jump (CMJ) performance of back squat exercises performed with or without elastic bands during warm-up were compared. After familiarization, fifteen active men visited the laboratory on two occasions under randomized, counterbalanced experimental squat warm-up conditions: (a) free-weight resistance (FWR) and (b) variable resistance (VR). After completing a comprehensive task-specific warm-up, three maximal CMJs were performed followed by three back squat repetitions completed at 85% of 1-RM using either FWR or VR Three CMJs were then performed 30 seconds, 4 minutes, 8 minutes, and 12 minutes later. During CMJ trials, hip, knee, and ankle joint kinematics, ground reaction force data and vastus medialis, vastus lateralis, and gluteus maximus electromyograms (EMG) were recorded simultaneously using 3D motion analysis, force platform, and EMG techniques, respectively. No change in any variable occurred after FWR (P > 0.05). Significant increases (P < 0.05) were detected at all time points following VR in CMJ height (5.3%-6.5%), peak power (4.4%-5.9%), rate of force development (12.9%-19.1%), peak concentric knee angular velocity (3.1%-4.1%), and mean concentric vastus lateralis EMG activity (27.5%-33.4%). The lack of effect of the free-weight conditioning contractions suggests that the comprehensive task-specific warm-up routine mitigated any further performance augmentation. However, the improved CMJ performance following the use of elastic bands is indicative that specific alterations in force-time properties of warm-up exercises may further improve performance.

Passive muscle stretching impairs rapid force production and neuromuscular function in human plantar flexors.

PURPOSE: We examined the effect of muscle stretching on the ability to produce rapid torque and the mechanisms underpinning the changes. METHODS: Eighteen men performed three conditions: (1) continuous stretch (1 set of 5 min), (2) intermittent stretch (5 sets of 1 min with 15-s inter-stretch interval), and (3) control. Isometric plantar flexor rate of torque development was measured during explosive maximal voluntary contractions (MVC) in the intervals 0-100 ms (RTDV100) and 0-200 ms (RTDV200), and in electrically evoked 0.5-s tetanic contractions (20 Hz, 20 Hz preceded by a doublet and 80 Hz). The rate of EMG rise, electromechanical delay during MVC (EMDV) and during a single twitch contraction (EMDtwitch) were assessed. RESULTS: RTDV200 was decreased (P < 0.05) immediately after continuous (- 15%) and intermittent stretch (- 30%) with no differences between protocols. The rate of torque development during tetanic stimulations was reduced (P < 0.05) immediately after continuous (- 8%) and intermittent stretch (- 10%), when averaged across stimulation frequencies. Lateral gastrocnemius rate of EMG rise was reduced after intermittent stretch (- 27%), and changes in triceps surae rate of EMG rise were correlated with changes in RTDV200 after both continuous (r = 0.64) and intermittent stretch (r = 0.65). EMDV increased immediately (31%) and 15 min (17%) after intermittent stretch and was correlated with changes in RTDV200 (r = - 0.56). EMDtwitch increased immediately after continuous (4%), and immediately (5.4%), 15 min (6.3%), and 30 min after (6.4%) intermittent stretch (P < 0.05). CONCLUSIONS: Reductions in the rate of torque development immediately after stretching were associated with both neural and mechanical mechanisms.

Acute Effects of Back Squats on Countermovement Jump Performance Across Multiple Sets of a Contrast Training Protocol in Resistance-Trained Men.

Bauer, P, Sansone, P, Mitter, B, Makivic, B, Seitz, LB, and Tschan, H. Acute effects of back squats on countermovement jump performance across multiple sets of a contrast training protocol in resistance-trained men. J Strength Cond Res 33(4): 995-1000, 2019-This study was designed to evaluate the voluntary postactivation potentiation (PAP) effects of moderate-intensity (MI) or high-intensity (HI) back squat exercises on countermovement jump (CMJ) performance across multiple sets of a contrast training protocol. Sixty resistance-trained male subjects (age, 23.3 ± 3.3 years; body mass, 86.0 ± 13.9 kg; and parallel back squat 1-repetition maximum [1-RM], 155.2 ± 30.0 kg) participated in a randomized, crossover study. After familiarization, the subjects visited the laboratory on 3 separate occasions. They performed a contrast PAP protocol comprising 3 sets of either MI (6 × 60% of 1-RM) or HI back squats (4 × 90% of 1-RM) or 20 seconds of recovery (CTRL) alternated with 7 CMJs that were performed at 15 seconds, and 1, 3, 5, 7, 9 and 11 minutes after the back squats or recovery. Jump height and relative peak power output recorded with a force platform during MI and HI conditions were compared with those recorded during control condition to calculate the voluntary PAP effect. Countermovement jump performance was decreased immediately after the squats but increased across all 3 sets of MI and HI between 3 and 7 minutes after recovery. However, voluntary PAP effects were small or trivial, and no difference between the 3 sets could be found. These findings demonstrate that practitioners can use MI and HI back squats to potentiate CMJs across a contrast training protocol, but a minimum of 3 minutes of recovery after the squats is needed to benefit from voluntary PAP.

Hip thrust-based PAP effects on sprint performance of soccer players: heavy-loaded versus optimum-power development protocols.

This study aimed to investigate the acute effects of two barbell hip thrust-based post-activation potentiation (PAP) protocols on subsequent sprint performance. Using a crossover design, eighteen soccer athletes performed 5 m, 10 m, and 20 m sprints before and 15 s, 4 min, and 8 min after two PAP protocols. The PAP conditioning activities consisted of hip thrust exercises loaded with either 85% 1RM or a load for optimum power development. The resulting 5 m and 10 m sprint performances were impaired at 15 s following both protocols. At 4 min and 8 min, meaningful improvements were observed for the three sprint distances following both of the protocols. Meaningful differences were found when comparing the two PAPs over time: greater impairments in 5 m and 10 m following the 85% of 1 RM protocol after 15 s, and greater improvements in all sprint distances after 4 min and 8 min following the optimum power development protocol. Positive correlations between the hip thrust's 1RM and power values and the overall individual PAP responses were found. This investigation showed that both heavy-loaded and optimum-power hip thrust exercises can induce a PAP response, with the optimum-power development protocol preferred due its higher efficiency.

Arthroplasty for glenohumeral arthritis in shoulders with a previous Bristow or Latarjet procedure.

BACKGROUND: Coracoid transfer has become increasingly popular for recurrent anterior shoulder instability. Despite the success, glenohumeral arthropathy develops in some patients. Arthroplasty in this population is complicated by altered anatomy, scarring, and retained hardware. This study evaluated shoulder arthroplasty in patients with a previous Latarjet or Bristow procedure. METHODS: Between 1980 and 2014, 33 patients underwent shoulder arthroplasty after coracoid transfer. Of these, 17 men and 13 women were monitored for a minimum of 2 years or until reoperation. Arthroplasty procedures included hemiarthroplasty (HA) in 5, total shoulder arthroplasty (TSA) in 14, and reverse shoulder arthroplasty (RTSA) in 11. Outcome measures included pain, range of motion, complications, and reoperations. RESULTS: At the most recent follow-up, pain had significantly improved in all arthroplasty groups. Elevation and external rotation also improved significantly (P < .001). Overall, 9 shoulders (30%) underwent revision for instability (1 TSA and 1 HA), glenoid loosening (1 TSA), instability and glenoid loosening (3 TSA), late cuff failure (1 TSA), and painful glenoid erosion (2 HA). Revision rates were significantly different between HA and RTSA (P = .0058) and between TSA and RTSA (P = .015). Radiographically, 2 additional anatomic glenoid components were considered loose, progressive medial erosion was seen in 1 HA, and grade 1 to 2 notching was observed in 2 RTSAs. CONCLUSIONS: Shoulder arthroplasty in patients after prior coracoid transfer is technically challenging, yet improvements in pain and function are predictable. Instability and glenoid loosening are common reasons for revision surgery, likely related to difficulties in achieving a good soft tissue balance.

Investigation of the predictive validity of laser-EPs in normal, UVB-inflamed and capsaicin-irritated skin with four analgesic compounds in healthy volunteers.

AIMS: The aim of the present study was to assess the predictivity of laser-(radiant-heat)-evoked potentials (LEPs) from the vertex electroencephalogram, using an algesimetric procedure, testing the anti-nociceptive/anti-hyperalgesic effects of single oral doses of four marketed analgesics (of different compound classes) vs. placebo, in healthy volunteers with three skin types. METHODS: This was a randomized, placebo-controlled, single-blind, five-way-crossover trial. Twenty-five healthy male/female Caucasians were included (receiving celecoxib 200 mg, pregabalin 150 mg, duloxetine 60 mg, lacosamide 100 mg or placebo) in a Williams design, with CO2 laser-induced painful stimuli to normal, ultraviolet (UV) B-inflamed and capsaicin-irritated skin. LEPs and visual analogue scale ratings were taken at baseline and hourly for 6 h postdose from all three skin types. RESULTS: In normal skin, the averaged postdose LEP peak-to-peak-(PtP)-amplitudes were reduced by pregabalin (-2.68 µV; 95% confidence interval (CI) -4.16, 1.19) and duloxetine (-1.73 µV; 95% CI -3.21, -0.26) but not by lacosamide and celecoxib vs. placebo. On UVB-irradiated skin, reflecting inflammatory pain, celecoxib induced a pronounced reduction in LEP PtP amplitudes vs. placebo (-6.2 µV; 95% CI -7.88, -4.51), with a smaller reduction by duloxetine (-4.54 µV; 95% CI -6.21, -2.87) and pregabalin (-3.72 µV; 95% CI -5.40, -2.04), whereas lacosamide was inactive. LEP PtP amplitudes on capsaicin-irritated skin, reflecting peripheral/spinal sensitization, as in neuropathic pain, were reduced by pregabalin (-3.78 µV; 95% CI -5.31, -2.25) and duloxetine (-2.32 µV; 95% CI -3.82, -0.82) but not by celecoxib or lacosamide vs. placebo, which was in agreement with known clinical profiles. Overall, PtP amplitude reductions were in agreement with subjective ratings. CONCLUSIONS: LEP algesimetry is sensitive to analgesics with different modes of action and may enable the effects of novel analgesics to be assessed during early clinical development.

Restoration of Articular Geometry Using Current Graft Options for Large Glenoid Bone Defects in Anterior Shoulder Instability.

PURPOSE: The purpose of this cadaveric study was to compare standard and modified coracoid transfer procedures, bicortical and tricortical iliac crest autografts, and tibial plafond and glenoid allografts with respect to glenoid surface curvature restoration. METHODS: Computed tomography scans of 8 cadaveric shoulders were acquired in 9 conditions: (1) intact, (2) 25% width defect, (3) classic Latarjet, (4) modified congruent-arc Latarjet, (5) tricortical iliac crest inner table, (6) outer table, (7) bicortical iliac crest, (8) distal tibia, and (9) glenoid allograft. Outcome measures included articular surface area, width, depth, axial and coronal radius of curvature, and subchondral articular step-off, analyzed in bone and soft-tissue window. RESULTS: Reconstruction of the articular surface area was optimal with the glenoid allograft (99.4%), classic Latarjet (97.4%), and iliac crest bicortical graft (93.2%). Depth was best restored by the congruent-arc Latarjet (101.0%), tibial (98.9%), and glenoid (95.3%) allografts. Axial curvature was closely matched by the glenoid allograft (97.5%), classic Latarjet (108.7%), and iliac bicortical graft (91.2%). Coronal curvature was most accurately restored by the glenoid allograft (102.6%), the tibial allograft (115.0%), and the classic Latarjet (55.9%). The articular step-off was smallest using the glenoid allograft. CONCLUSIONS: Overall, glenoid allografts most accurately restored articular geometry. Alternative grafts provided restoration of some parameters but not others. Classic Latarjet performed well in axial and coronal curvature on average but exhibited large variability. Tibial allograft produced the poorest results in axial curvature, despite excellent coronal curvature reconstruction. The congruent-arc Latarjet did not restore the axial curvature accurately and overcorrected coronal curvature. Graft geometry must be weighed against availability, morbidity, and the role of additional stabilizers. CLINICAL RELEVANCE: Accurate graft morphology may help prevent postoperative osteoarthritis. Grafts differ significantly regarding geometric parameters. The findings of this study will help surgeons select the most appropriate graft for glenoid reconstruction.

Variable Resistance Training Promotes Greater Strength and Power Adaptations Than Traditional Resistance Training in Elite Youth Rugby League Players.

Rivière, M, Louit, L, Strokosch, A, and Seitz, LB. Variable resistance training promotes greater strength and power adaptations than traditional resistance training in elite youth rugby league players. J Strength Cond Res 31(4): 947-955, 2017-The purpose of this study was to examine the strength, velocity, and power adaptations in youth rugby league players in response to a variable resistance training (VRT) or traditional free-weight resistance training (TRAD) intervention. Sixteen elite youth players were assigned to a VRT or TRAD group and completed 2 weekly upper- and lower-body strength and power sessions for 6 weeks. Training programs were identical except that the VRT group trained the bench press exercise with 20% of the prescribed load coming from elastic bands. Bench press 1 repetition maximum (1RM) and bench press mean velocity and power at 35, 45, 65, 75, and 85% of 1RM were measured before and after the training intervention, and the magnitude of the changes was determined using effect sizes (ESs). The VRT group experienced larger increases in both absolute (ES = 0.46 vs. 0.20) and relative (ES = 0.41 vs. 0.19) bench press 1RM. Similar results were observed for mean velocity as well as both absolute and relative mean power at 35, 45, 65, 75, and 85% of 1RM. Furthermore, both groups experienced large gains in both velocity and power in the heavier loads but small improvements in the lighter loads. The improvements in both velocity and power against the heavier loads were larger for the VRT group, whereas smaller differences existed between the 2 groups in the lighter loads. Variable resistance training using elastic bands may offer a greater training stimulus than traditional free-weight resistance training to improve upper-body strength, velocity, and power in elite youth rugby league players.

Intracranial Hypertension Is Painless!

INTRODUCTION: Headache is usually considered a key symptom of intracranial hypertension (ICHT). However, there are no published experimental data to support the concept that increased intracranial pressure (ICP) is painful in humans. MATERIALS AND METHODS: This prospective study was performed in 16 patients with suspected normal-pressure hydrocephalus, necessitating a lumbar infusion test with measurement of cerebrospinal fluid (CSF) hydrodynamics. During the test, ICP was increased from baseline to a plateau. Headache was scored on a visual analog scale (VAS) (0 = no pain, 10 = very severe pain) at baseline ICP and when ICP plateaued. RESULTS: At baseline, mean ICP was 11 ± 3.6 mmHg and VAS was 0. At plateau, mean ICP was 28 ± 9.5 mmHg and VAS was 0. There was a significant increase in ICP (p <0.001), but no increase in headache intensity (VAS). An acute (20-min) moderate increase in ICP was not accompanied by a headache. DISCUSSION: We demonstrate that an acute, isolated increase in CSF pressure does not produce a headache. To occur, a headache needs activation of the pain-sensitive structures (dura and venous sinuses) or central activation of the cerebral nociceptive structures. This peripheral or central activation does not occur with an isolated increase in CSF pressure.

Postactivation Potentiation of Horizontal Jump Performance Across Multiple Sets of a Contrast Protocol.

Seitz, LB, Mina, MA, and Haff, GG. Postactivation potentiation of horizontal jump performance across multiple sets of a contrast protocol. J Strength Cond Res 30(10): 2733-2740, 2016-This study determined whether a postactivation potentiation (PAP) effect could be elicited across multiple sets of a contrast PAP protocol. Fourteen rugby league players performed a contrast PAP protocol comprising 4 sets of 2 paused box squats accommodated with bands alternated with 2 standing broad jumps. The rest period between the squats and the jumps and between the sets was 90 seconds. A control protocol with standing broad jumps only was performed on a separate session. A standing broad jump was performed ∼2 minutes before each protocol and served as a baseline measurement. Standing broad jump distance was significantly greater (4.0 ± 3.4% to 5.7 ± 4.7%) than baseline during the 4 sets of the contrast PAP protocol with the changes being medium in the first, second, and fourth sets (effect size [ES]: 0.58, 0.67, and 0.69, respectively) and large for the third set (ES: 0.81). Conversely, no PAP effect was observed in the control protocol. Additionally, the stronger players displayed a larger PAP effect during each of the 4 sets of the contrast PAP protocol (Cohen's d: 0.28-1.68) and a larger mean effect across these 4 sets (Cohen's d: 1.29). Horizontal jump performance is potentiated after only 90 seconds of rest after an accommodating exercise, and this PAP effect can be elicited across 4 sets. Additionally, the PAP response is largely mediated by the individual's strength level. These results are of great importance for coaches seeking to incorporate PAP complexes involving horizontal jumps in their training programs.

Iliac bone grafting of the intact glenoid improves shoulder stability with optimal graft positioning.

BACKGROUND: Bone grafting procedures are increasingly popular for the treatment of anterior shoulder instability. In patients with a high risk of recurrence, open coracoid transplantation is preferred but can be technically demanding. Free bone graft glenoid augmentation may be an alternative strategy for high-risk patients without significant glenoid bone loss. This biomechanical cadaveric study assessed the stabilizing effect of free iliac crest bone grafting of the intact glenoid and the importance of sagittal graft position. METHODS: Eight fresh frozen cadaveric shoulders were tested. The bone graft was fixed on the glenoid neck at 3 sagittal positions (50%, 75%, and 100% below the glenoid equator). Displacement and reaction force were monitored with a custom device while translating the humeral head over the glenoid surface in both anterior and anteroinferior direction. RESULTS: Peak force (PF) increased significantly from the standard labral repair to the grafted conditions in both anterior (14.7 ± 5.5 N vs 27.3 ± 6.9 N) and anteroinferior translation (22.0 ± 5.3 N vs 29.3 ± 6.9 N). PF was significantly higher for the grafts at the 50% and 75% positions compared with the grafts 100% below the equator with anterior translation. Anteroinferior translation resulted in significantly higher values for the 100% and 75% positions compared with the 50% position. CONCLUSIONS: This biomechanical study confirms improved anterior glenohumeral stability after iliac crest bone graft augmentation of the anterior glenoid. The results also demonstrate the importance of bone graft position in the sagittal plane, with the ideal position determined by the direction of dislocation.

Accuracy of the glenohumeral subluxation index in nonpathologic shoulders.

BACKGROUND: Correction of posterior humeral subluxation, measured by the humeral subluxation index (HSI) according to Walch, is necessary in total shoulder arthroplasty to prevent early loosening. The 3-dimensional (3D) measurement of the shoulder is becoming well accepted and common practice as it overcomes positional errors to which 2-dimensional (2D) glenohumeral measurements are prone. The first objective was to describe the HSI in a nonpathologic population with the 2D HSI according to Walch and a newly described 3D HSI method. The second objective was to compare both measuring methods with each other. METHODS: In 151 nonpathologic shoulders, the 2D HSI was measured on the midaxial computed tomography scan cut of the scapula. The 3D HSI, based on the native glenoid plane, was defined as [formula in text], in which X is the projection of the center of the humeral head to the anteroposterior axis of the glenoid fossa and R is the radius of the humeral head. Both measuring methods were compared with each other. Correlation was determined. Interobserver and intraobserver reliability of the 3D HSI was measured. RESULTS: The mean 3D HSI (51.5% ± 2.7%) was significantly (P < .001) more posterior than the mean 2D HSI (48.7% ± 5.2%), with a mean difference of 2.9% ± 5.6%. No correlation was found between the 2D and 3D HSI. The interobserver and intraobserver reliability was excellent. CONCLUSION: The 2D HSI seems to underestimate the humeral subluxation compared with a 3D reliable equivalent.

Investigation of combined CYP3A4 inductive/inhibitory properties by studying statin interactions: a model study with the renin inhibitor ACT-178882.

PURPOSE: ACT-178882, a direct renin inhibitor, was used as a model compound in an elaborate drug-drug interaction study with atorvastatin and simvastatin to explore complex CYP3A4 inductive and inhibitory properties. METHODS: Thirty-two healthy male subjects received single doses of 20 mg atorvastatin and 20 mg simvastatin on days 1, 9, 31, and 41. On days 6 to 33, 500 mg ACT-178882 was administered once daily. Plasma concentrations of ACT-178882, simvastatin, and atorvastatin were measured by LC-MS/MS. Routine safety assessments were performed throughout the study. RESULTS: Exposure (as based on area under the curve) to simvastatin and 6ß-hydroxyacid simvastatin increased (90 % confidence interval) 4.63-fold (3.90, 5.50) and 3.71-fold (3.19, 4.32), respectively, when comparing day 9 and day 1. On day 9, exposure to atorvastatin was similar but Cmax decreased, while both variables decreased for ortho-hydroxy atorvastatin when compared to day 1. On day 31, after prolonged administration of ACT-178882, exposure to atorvastatin, ortho-hydroxy atorvastatin, simvastatin, and 6ß-hydroxyacid simvastatin decreased by 14, 19, 21, and 27 %, respectively, when compared to day 9. However, on this day, exposure to simvastatin and its metabolite was still markedly higher when compared to day 1. Effects of ACT-178882 had largely dissipated on day 41. CONCLUSIONS: This design enabled the study of complex time-dependent effects on CYP3A4 activity with clinically relevant substrates.

The athletic performance of elite rugby league players is improved after an 8-week small-sided game training intervention.

The purpose of this investigation was to determine the effects of a small-sided game training intervention on the intermittent shuttle running performance, speed, and repeated sprint ability of elite rugby league players during the competitive phase of a rugby league season. Ten elite rugby league players from a Stobart Super League team academy underwent 2 small-sided game sessions per week over an 8-week period. Each session consisted of four 10-minute blocks of 1 small-sided game, interspersed with a 3-minute recovery. Changes in physical performance were assessed before and after the training intervention with an intermittent shuttle running test (30-15 Intermittent Fitness Test), speed tests (10-, 20-, and 40-m linear sprints) and a repeated sprint ability test (8 × 20-m linear sprint, departing every 20 seconds). Results showed that the 30-15 Intermittent Fitness Test (+1.29%), 10-m (-3.17%), 20-m (-1.37%), and 40-m (-0.96%) sprint times and mean sprint time (-2.11%), total sprint time (-2.11%), and percentage of sprint decrement (7.10 vs. 5.93%) during the repeated sprint ability test were significantly improved after the training intervention. Based on these results, it was concluded that an 8-week small-sided game training intervention was an effective method for improving the physical performance of elite rugby league players during the competitive phase of the season.

The temporal profile of postactivation potentiation is related to strength level.

The purpose of this investigation was to determine whether stronger individuals are able to express postactivation potentiation (PAP) earlier than weaker individuals during a vertical squat jump test. Eighteen junior elite rugby league players were divided into strong (relative 1 repetition maximum [1RM] back squat ≥ 2 × body mass) and weak (relative 1RM back squat <2.0 × body mass) groups. Each subject performed squat jumps before, 15 seconds, 3, 6, 9, and 12 minutes after a conditioning activity (CA) that contained 1 set of 3 back squats performed at 90% of 1RM. A force plate, which sampled at 1000 Hz, was used to determine the power output and height for each squat jump. Stronger individuals expressed PAP between 3 and 12 minutes post-CA, whereas their weaker counterparts displayed potentiation between 6 and 12 minutes post-CA. Moreover, the stronger group exhibited a significantly (p ≤ 0.05) higher PAP response than the weaker group at all post-CA squat jump tests. The stronger group displayed the greatest potentiation at 6 minutes post-CA, whereas the weaker group displayed the greatest potentiation response at 9 minutes following the CA. Based on these results, stronger individuals appear to be able to express PAP earlier after a CA than weaker individuals. Additionally, stronger individuals express significantly greater postactivation responses than weaker individuals. From a practical standpoint, strength and conditioning coaches should consider the athletes' strength levels when constructing postactivation complexes (CA + performance activity) as strength will dictate the time frame required between the conditioning and the performance activity.