Accuracy of unilateral and bilateral gait assessment using a mobile gait analysis system at different walking speeds.

BACKGROUND: Previous research on the accuracy of mobile measurement systems has focused on parameters related to the whole gait cycle. Specifically, bilateral gait characteristics were primarily used as outcome measures. RESEARCH QUESTION: How accurate are unilateral gait characteristics detected using a mobile system at various fixed walking speeds? METHODS: Gait analysis during treadmill walking at velocities (VEL) of 2.5 (v1), 4.5 (v2) and 6.5 km/h (v3) was performed in a population of 47 healthy young adults, consisting of 27 females (age: 23 ± 2 years, BMI: 21.4 ± 2.2 kg/m²) and 20 males (age: 22 ± 1 years, BMI: 23.3 ± 3.4 kg/m²). Spatiotemporal gait data were simultaneously determined using an instrumented treadmill (gaitway 3D) and a mobile gait analysis system (RehaGait). Besides VEL, bilateral (stride length [SL], cadence [CAD]) and unilateral (contact duration [CON], single [SS] and double support duration [DS]) outcomes were validated. RESULTS: Across the three VEL investigated, the correlations between both measurement systems were almost perfect in SL and CAD (r > 0.97). In addition, SL significantly differed (p < 0.01) with moderate to large effects, whereby the root mean squared error (RMSE) did not exceed 1.8 cm. RMSE in CAD was not higher than 0.33 spm and statistically significant differences were only present at v1 (d = 0.63). DS was the most erroneous unilateral parameter with values for %RMSE ranging from 9% at v1 to 14% at v3. In CON and SS %RMSE was in a magnitude of 2-4% across all VEL. Furthermore, VEL affected measurement accuracy in unilateral outcomes with moderate to large effects (F (2, 45) > 6.0, p < 0.01, ηp2 > 0.11) with consistently higher differences at lower velocities. SIGNIFICANCE: Based on the results presented the validity of the mobile gait analysis system investigated to detect gait asymmetries must be questioned.

Longitudinal Analysis of the ASES and Constant-Murley Scores, and the Internal Rotation/Shift and Jobe Tests Following Arthroscopic Repair of Supraspinatus Lesions.

It is essential to investigate patients post-surgery using functional surveys like the American Shoulder and Elbow Surgeons Shoulder (ASES) and the Constant-Murley shoulder (CMS) scores, as well as clinical tests, such as the Internal Rotation and Shift (IRO/Shift) and Jobe tests. In this study, 51 out of an initial 87 patients underwent an arthroscopic supraspinatus repair (22 single-row, 16 double-row, 13 debridement). Testing occurred pre-surgery, and 3 and 6 months post-surgery. Both surveys showed significant improvements over time among all 87 patients, but there were no differences between groups (lesion/no lesion) (p > 0.815) or time × group (p > 0.895). The IRO/Shift test showed a stronger ability to distinguish between both groups (positive vs. negative) with respect to the ASES and CMS scores over time, but the Jobe test did not (p > 0.100). Improvements in the CMS scores and the Jobe test were lower following repair compared to the ASES and IRO/Shift test. Most patients returned to adequate levels of functional abilities at 6 months post-surgery. The time required to return to activities of daily living and negative clinical tests was longer for the double-row repair patients compared to the single-row and debridement groups. In conclusion, both the functional surveys and the clinical tests demonstrated improvements following surgery.

A Longitudinal Analysis of the Internal Rotation and Shift (IRO/Shift) Test Following Arthroscopic Repair of Superior Rotator Cuff Lesions.

Although the use of clinical tests to diagnose superior rotator cuff pathology is common, there is paucity in the research regarding the accuracy of such tests following arthroscopic repair. The aim of this study was to determine the accuracy of the IRO/Shift test compared to the Jobe test at 3 months and 6 months post-surgery for superior rotator cuff repair. Arthroscopic repair was conducted on 51 patients who were subsequently seen for clinical evaluation at 3 and 6 months following surgery. At 3 months post-surgery only 27% of the patients had a negative IRO/Shift test and 18% had a negative Jobe test. However, at 6 months 88% of the patients presented with a negative IRO/Shift test and 61% a negative Jobe test. When compared to each other, the IRO/Shift test and the Jobe test had 90% agreement pre-operatively, 71% agreement at 3 months post-surgery, and 67% agreement at 6 months. These results demonstrate that the accuracy of the IRO/Shift test and the Jobe test improved between 3 and 6 months following arthroscopic surgery of the superior rotator cuff, with the IRO/Shift test having better accuracy.

IRO/Shift Test Is Comparable to the Jobe Test for Detection of Supraspinatus Lesions.

To determine how the internal rotation and shift (IRO/shift) test compares to the gold standard of clinical tests (Jobe test) for diagnosing supraspinatus lesions and to confirm these clinical results with surgical findings, 100 symptomatic patients were clinically examined between October 2018 and November 2019. All 100 patients were evaluated using both the IRO/shift test and Jobe test. A total of 48 of these patients received surgical intervention. Based on these data, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for both the IRO/shift test and Jobe test were calculated. The IRO/shift test had a sensitivity of 96% (95% CI: 82-100%), specificity of 50% (95% CI: 27-73%), PPV of 73% (95% CI: 56-86%), NPV of 91% (95% CI: 59-100%), and an accuracy of 77% (95% CI: 63-88%). The Jobe test had a sensitivity of 89% (95% CI: 72-98%), specificity of 60% (95% CI: 36-81%), PPV of 76% (95% CI: 58-89%), NPV of 80% (95% CI: 52-96%), and an accuracy of 77% (95% CI: 54-81%). These results suggest that the IRO/shift test is comparable to the Jobe test, which is often viewed as the gold standard clinical examination for assessing supraspinatus lesions. This study was approved by the Ethics Commission of the Martin Luther University Halle-Wittenberg (reference number: 2018-05).

The internal rotation and shift-test for the detection of superior lesions of the rotator cuff: reliability and clinical performance.

Background: Using reliable and valid clinical tests are essential for proper diagnosis and clinical outcomes among injuries involving the rotator cuff. The addition of a new clinical examination test could improve the clinical diagnosis and informative value of the sensitivity and specificity of pathology. This study of diagnostic accuracy evaluated the use of a new rotator cuff test, called the internal rotation and shift-test (IRO/shift-test), to determine its reliability and clinical performance (sensitivity, specificity, positive (PPV)/negative predictive value (NPV)). Clinical diagnostic outcomes were confirmed with radiological findings (MRI). Methods: 100 patients from a specialized shoulder unit participated (64 male, 36 female, mean age: 55 ± 13.5 years). A single-blinded (no knowledge of prior clinical or technical diagnostics) study design was used with two experienced physicians performing the IRO/shift-test. For clinical performance, all clinical testing was compared with MRI. Results: The intra-rater (ICC = 0.73, 95% CI: 60-82) and inter-rater (ICC = 0.89, 95% CI: 81-94) coefficients for the IRO/shift-test showed good-to-excellent reliability. 75% of the patients showed a positive IRO/shift-test, while 65% had a radiologically diagnosed superior rotator cuff tear. 60% of these patients had both a positive IRO/shift-test and objective rotator cuff tear via MRI. The sensitivity of the IRO/shift-test to detect superior rotator cuff lesions based on MRI diagnosis was calculated at 92% (95% CI: 86-99%), while specificity was 67% (95% CI: 50-84%). Predictive values were also found to be high with 86% PPV (95% CI: 78-94%) and 80% NPV (95% CI: 64-96%). Conclusion: Our results demonstrate that the IRO/shift-test is a reliable and valid tool for assessing superior rotator cuff pathology. With good-to-excellent intrarater and inter-rater reliability and strong sensitivity and specificity this test should be considered a valuable addition to clinicians' cadre of clinical evaluation tools.

[Reasons and risk factors for recurrent retinal detachment after removal of silicon oil in various vitreoretinal diseases]. / Ursachen und Risikofaktoren für eine erneute Netzhautablösung nach Silikonölentfernung bei verschiedenen vitreoretinalen Grunderkrankungen.

BACKGROUND: Pars plana vitrectomy (ppV) combined with silicone oil tamponade is a standard technique in the treatment of complicated retinal detachment. There are still recurrent cases of retinal detachment after silicone oil removal or redetachment with in situ oil tamponade. OBJECTIVE: The aim was to identify possible risk factors for retinal redetachment and to use the knowledge for optimizing treatment. METHODS: Analysis of data from patients who were treated with ppV and silicone oil tamponade in the University Department of Ophthalmology in Marburg during 2010-2015 and who had a retinal redetachment during this period. The results were divided into two groups, redetachment with oil in situ and redetachment after oil removal. RESULTS: A total of 43 cases (15.6%) had a redetachment, which included 22/43 cases (50%) with a redetachment after oil removal and 21/43 cases (50%) with redetachment with oil in situ. The cause for the renewed detachment was given as proliferative vitreoretinopathy (PVR) in 90.6% (39/43) of the cases, new foramina in 20.9% (9/43) and persisting foramina in 25.5% (11/43). CONCLUSION: Vitreoretinal scar formation (PVR reaction) was the main risk factor for renewed retinal detachment. Persisting foramina were also named as a frequent cause. Recurrent retinal detachment represents a significant challenge for vitreoretinal surgeons and for the patients considering the economic and emotional burden due to multiple interventions.

Cardiovascular Risk Reduction in Women Following Hypertensive Disorders of Pregnancy - a Prospective, Randomised, Controlled Interventional Study.

Background Women have a markedly increased lifetime risk for cardiovascular morbidity and mortality following hypertensive disorders of pregnancy. Arterial stiffness is regarded as a target parameter for reducing cardiovascular risk and can be modified by lifestyle changes. Methods In a prospective, randomised, controlled interventional study, starting 6 weeks postpartum, the effect of nutritional intervention combined with an intensive 6-month cardiovascular exercise programme on arterial stiffness was investigated by means of pulse wave velocity (PWV) in 38 women with severe hypertensive disorder of pregnancy (preeclampsia with or without pre-existing hypertension and/or HELLP syndrome). A reference group was formed with postpartum women without pregnancy complications or known cardiovascular risk and the arterial stiffness was studied by means of PWV at the time of delivery. The PWV was measured in the intervention and control groups within a week after delivery and after 32 weeks (6 weeks + 6 months). A feasibility analysis was performed in addition. Results 29 of 38 women with severe hypertensive disorder of pregnancy and 38 postpartum women in the reference group were included in the analysis (intervention group n = 14; control group n = 15; reference group n = 38). Adherence to a) the nutritional counselling and b) the intensive cardiovascular exercise programme was 73% and 79% respectively. A clinically significant difference (d = 0.65) in pulse wave velocity between the intervention and control groups was found after 6 months (6.36 ± 0.76 vs. 7.33 ± 2.25 m/s; group × time: p = 0.632). The PWV of the intervention group corresponded to that of the reference group at the end of the study (6.36 ± 0.76 m/s vs. 6.5 ± 0.70; d = 0.19), while the results in the control group differed markedly from this (7.33 ± 2.25 m/s; d = 0.56). Conclusion The study documents the feasibility of lifestyle intervention with physical exercise after delivery (starting 6 weeks postpartum). The intervention showed a significant clinical effect by reducing arterial stiffness to the level of the reference group. Before this intervention can be included in the standard of care and prevention, follow-up studies must confirm these results and the medium-term effects on cardiovascular risk.

An Investigation into the Relationship Between Heart Rate Recovery in Small-Sided Games and Endurance Performance in Male, Semi-professional Soccer Players.

BACKGROUND: The ability to recover in the shortest possible time plays an important role especially in intermittent sports such as soccer. Evidence suggests that a well-developed endurance performance has positive effects on the repeated-sprint ability and thus also on the short-term recovery. However, it has not been clarified whether these relationships still exist in a soccer-specific situation. Therefore, the purpose of this investigation was to evaluate the ability of semi-professional soccer players to recover during standardized small-sided games (SSGs) as an endurance performance indicator. METHODS: Eighteen male semi-professional soccer players (age, 23.5 ± 3.7 years) performed an incremental treadmill test (ITT) to determine their running velocity and heart rate at a fixed lactate threshold of 4 mmol L-1 (v4). Two days later, the players carried out six bouts of 4 vs. 4 SSGs (duration, 90 s; load to rest ratio, 1:1). A GPS-based tracking system was used to determine distances covered at four fixed speed zones (i.e., < 7.2 km/h, 7.2-14.4 km/h, 14.4-19.8 km/h, > 19.8 km/h) and total distance covered during the SSGs. Furthermore, the frequency of occurrence of accelerations (> 1.54 m s-2) was calculated. SSGs' internal load was quantified by average heart rate and blood lactate concentration after the SSGs. Their recovery ability was evaluated using heart rate recovery (HRR) after the last bout of the SSGs. RESULTS: A very large correlation (r = - .91) with an explained variance of 84% was found between HRR and v4. Further, a better performance in the ITT was also related with a higher number of accelerations executed during SSGs (r = .60). The total distance and distances in predefined speed zones did not show any association to v4. CONCLUSIONS: This study showed a strong relationship between HRR after standardized 4 vs. 4 SSGs and the soccer players' endurance performance in a laboratory setting. Thus, besides being associated with endurance capacity, v4 seems sufficient to evaluate the sport-specific ability to recover in soccer players.

Physical Match Performance in Sub-elite Soccer Players - Introduction of a new Index.

This investigation examined the position-specific physical performance in different locomotor categories and physiological demands concurrently in official games of sub-elite players and to present a new performance index (PI). Time-motion (distance, velocity, acceleration) and heart rate data of 55 soccer players were simultaneously captured via a GPS tracking system. The relationship between external and internal match-load (PI) was determined on the basis of heart rate, average velocity and acceleration. In contrast to the mean heart rate (85.2±3.2%, P=0.806, ηp²=0.03), the average total distance covered (9946±715 m) was largely affected by players' position (P<0.001, ηp²=0.63). Furthermore, a mixed design ANOVA showed a large interaction effect between position and locomotor category (P<0.001, ηp²=0.44). On average, PI was 1.57±0.37 m/min²/%, with notably lower values in the 2nd half. The position-specific profiles already reported for higher leagues were also present in sub-elite soccer players. Despite lower values for total distance and smaller distances in the high-intensity zones (>14.4 km/h), internal loads were comparable to those observed in European top leagues. In comparison to a performance measure that ignores accelerations, PI was shown to be less dependent on the playing position and had higher variability. Consequently, PI is better suited to distinguish between players' performance.

Differences in Player Position Running Velocity at Lactate Thresholds Among Male Professional German Soccer Players.

This study investigated the differences in running velocities at specific lactate thresholds among male German soccer players. One hundred fifty-two professional (3rd league: n = 78; 4th league: n = 74) male soccer players (mean ± SD; age: 24.7 ± 4.37 years, body mass: 80.8 ± 7.33 kg, body height: 1.83 ± 0.06 m) volunteered for the investigation. Players were categorized as goalkeepers, central defenders, central midfielders, wings and forward. Players completed a treadmill test, at incremental speeds, to determine running velocity at different blood lactate concentrations (v2 = 2 mmol/l; v4 = 4 mmol/l; and v6 = 6 mmol/l). In addition, the largest difference between positions for running velocity was found at the lactate threshold v2 (p = 0.005). The running data revealed that only goalkeepers had significantly lower velocities at the lactate thresholds compared to outfield players. The central midfielders showed the highest average performance level at the lactate thresholds (v2: 12.5 ± 1.20 km/h; v4: 15.2 ± 1.14 km/h; and v6: 16.6 ± 1.14 km/h). In conclusion, this study provides soccer and position-specific reference data for the running performance of male professional German soccer players to evaluate the endurance performance in a standardized way. In this context, future research should extend the database for the first and second leagues. Further research assessing running performance during competition matches over the entire season is required to validate the endurance test performance data.

Enhanced sprint performance analysis in soccer: New insights from a GPS-based tracking system.

The aim of this investigation was to establish the validity of a GPS-based tracking system (Polar Team Pro System, PTPS) for estimating sprint performance and to evaluate additional diagnostic indices derived from the temporal course of the movement velocity. Thirty-four male soccer players (20 ± 4 years) performed a 20 m sprint test measured by timing gates (TG), and while wearing the PTPS. To evaluate the relevance of additional velocity-based parameters to discriminate between faster and slower athletes, the median-split method was applied to the 20-m times. Practical relevance was estimated using standardized mean differences (d) between the subgroups. Differences between the criterion reference (TG) and PTPS for the 10 and 20 m splits did not vary from zero (dt10: -0.01 ± 0.07 s, P = 0.7, d < -0.1; dt20: -0.01 ± 0.08 s, P = 0.4, d < -0.2). Although subgroups revealed large differences in their sprint times (d = -2.5), the average accelerations between 5 and 20 km/h as well as 20 and 25 km/h showed merely small effects (d < 0.5). Consequently, analyses of velocity curves derived from PTPS may help to clarify the occurrence of performance in outdoor sports. Thus, training consequences can be drawn which contribute to the differentiation and individualization of sprint training.

Does low back pain affect the reliability of postural regulation?

The aim of this study was to examine the intraobserver reliability of a posturographic assessment in patients with low back pain. We investigated 24 symptomatic subjects with defined low back pain (mean: 57.9 years) and a pair-matched control group including 24 asymptomatic persons (mean: 58.1 years). Each participant underwent two measurements on a posturographic device (32 Hz sampling rate) based on the Interactive Balance System (time interval: 7 d). Test procedure consisted of tests on solid ground with eyes open (1) and eyes closed (2). Data analysis included parameters of motor output and a frequency band analysis. Reliability tests were realized using by intraclass correlations (ICC). Coefficients of ICC ranged from 0.36 (95% CI: 0.01-0.73) to 0.94 (95% CI: 0.86-0.97) in both test positions. For 69% (11/16) of the investigated parameters a high level (ICC > 0.75) of intraobserver reliability was reached. Based on the results, the posturographic measurement system used in this study seems to be appropriate for use in longitudinal study designs in an orthopaedic setting.

Postural stability and regulation before and after anterior cruciate ligament reconstruction - A two years longitudinal study.

OBJECTIVES: To evaluate postural regulation and stability among patients who underwent anterior cruciate ligament reconstruction (ACLR) and rehabilitation over a two-year follow-up period. DESIGN: Longitudinal; SETTING: Biomechanics laboratory; PARTICIPANTS: 30 ACLR patients (32.0 ±â€¯12.2 years, 14 males) with isolated ACL rupture. MAIN OUTCOME MEASURES: Postural regulation was tested before ACLR, as well as at six-weeks, twelve-weeks, six-months, one-year and two-years post-ACLR and standardized rehabilitation. Postural regulation was measured for stability indicator (ST), weight distribution index (WDI), synchronization (foot coordination) and sway intensities (postural subsystems). RESULTS: Significant time effects (pre-vs. two-years postoperative) were found for WDI (ηp2 = 0.466), synchronization (ηp2 = 0.368), mediolateral weight distribution (ηp2 = 0.349), ST (ηp2 = 0.205), visual/nigrostriatal systems (ηp2 = 0.179) and peripheral-vestibular system (ηp2 = 0.102). The largest difference (preoperative: ηp2 = 0.180) to the matched sample was calculated for WDI. The most significant differences to the matched sample were observed for ST (preoperative: ηp2 = 0.126; six-weeks postoperative: ηp2 = 0.103) and WDI (preoperative: ηp2 = 0.180; six-weeks postoperative: ηp2 = 0.174). CONCLUSION: ACLR and rehabilitation influence postural subsystems, postural stability, weight distribution and foot synchronization. Normalization of mediolateral weight distribution requires one year following ACLR. The ACLR leads to a suppression of the somatosensory and cerebellar system which was compensated by a higher activity of the visual and nigrostriatal systems.

Relationships between maximal strength of lower limb, anthropometric characteristics and fundamental explosive performance in handball players.

BACKGROUND: The purpose of this study was to examine relationships between lower body muscular strength, anthropometric characteristics and several measures of explosive performance in elite team-handball players. METHODS: 22 male elite team-handball players (age: 19.1 ±â€Š1.7 years) were studied during the competitive season. Standard anthropometric and body composition measures included body mass index, lower limb and thigh muscle volume, and body fat percentage. Maximal leg strength was determined by a one-repetition maximum (1-RM) half back-squat. Vertical jump performance was assessed using a squat jump (SJ) and a counter movement jump (CMJ). Repeated shuttle-sprint ability (RSA) was tested by 6 (2 × 15 m) shuttle sprints with 20 s of active recovery intervals. The best time in a single shuttle sprint (30m; RSAbest), fastest total time (RSATT) and RSA test performance decrement (RSAdec) were recorded. Agility was measured using a modified T-half test (MAT). Throwing velocities of jump shooting and 3-step throwing were recorded by digital video camera. RESULTS: The explained variance of 1-RM half-back-squats ranged from 0.2 % (RSA% Fatigue Index) to 70.1 % (CMJ). Four out of 8 variables (RSA Best Time, CMJ, SJ, throwing velocity of jump shoot) demonstrated an r2 > 0.5. Jump performances seemed closely related to 1-RM half-back-squats. Furthermore, 1-RM half-back-squats were positively correlated with leg and thigh muscle volumes (r = 0.652, r = 0.768). CONCLUSION: The anthropometric characteristics and some physical performance tests are closely related to the maximal strength performance of handball players. Coaches should focus on maximal strength training programs for the lower limbs when seeking improvements in the throwing velocity and jump performance of handball players.

Relationships Between Olympic Weightlifting Exercises, Peak Power of the Upper and Lower Limb, Muscle Volume and Throwing Ball Velocity in Elite Male Handball Players.

BACKGROUND: This study aimed to investigate relationships between peak power (PP) as measured by upper limb (PPUL) and lower limb (PPLL) force velocity tests, maximal upper limb force assessed by clean and jerk (1RMCJ) and snatch (1RMSE) exercises, estimates of local muscle volume and throwing ball velocity. METHODS: Thirty elite male handball players volunteered for the investigation (age: 20.3 ±â€Š2.1 years; body mass: 82.5 ±â€Š10.5 kg; height: 1.85 ±â€Š0,07 %; body fat: 13.1 ±â€Š2.1 %). Lower and upper limb force velocity tests were performed on appropriately modified forms of a Monark cycle ergometer with measurement of PPUL and PPLL, and the corresponding respective maximal forces (F0UL and F0LL) and velocities (V0UL and V0LL). Snatched (SN) and clean and jerk (CJ) exercises were performed to one repetition maximum (1RM). Handball throwing velocity was measured with jump shot (JS) without run-up (TW) and 3 steps shot (T3 step). Muscle volumes of the upper and lower limbs were estimated with a standard anthropometric kit. RESULTS: The 1RM CJ proved to be the most important predictor for throwing velocity. All types of throwing showed a high correlation with this parameter (JS: r = 0.75; TW: r = 0.62; T3 step: r = 0.66). The highest relation was detected between jump shot and 1RM snatch technique (r = 0.82). The PPUL muscle volume correlated highly with PPUL absolute power (r = 0.70). In contrast, we did not find any comparable relations for the lower limb (muscle volume vs. PPUL absolute power: r = 0.07). CONCLUSIONS: Our results highlight the contribution of both lower and upper limbs to handball throwing velocity, suggesting the need for coaches to include upper and lower limb strength weightlifting exercises and power programs when improving the throwing velocity of handball players.

Reliability of an ice hockey-specific complex test.

BACKGROUND: This study assessed the intra-rater reliability of an ice hockey-specific complex test (IHCT) that reflects the intense multidirectional and intermittent efforts required in ice hockey. METHODS: Twenty professional players executed the IHCT twice over an interval of 2 days. Load parameters included a 10-m sprint, a 30-m transition with and without a puck, as well as slap and wrist shots. Stress parameters were lactate concentrations and heart rates. RESULTS: The intrarater reliability (ICC) ranged from 0.54 to 0.98 for load parameters, and from 0.26 to 0.87 for stress parameters. 33 % (3/9) of stress parameters and 82 % (18/22) of load parameters had an ICC > 0.75. The largest limits of agreement were 41.6 for slap shot 1 after test and 50.4 for 6-min heart rate recovery. The smallest were 0.40 (10-m sprint without a puck) and 5.36 (resting lactate). The intra-rater reliability as shown by the coefficient of variation (CV) was lower for stress than for load parameters (mean CV: 13.4 vs. 4.7). 68 % (15/22) of load parameters and 11 % (1/9) of stress parameters showed a CV below 5 %. CONCLUSION: The IHCT is currently the only ice hockey-specific complex test with scientifically tested reliability and validity that can analyze performance under conditions similar to competition. It is suggested that coaches, fitness coaches and sports scientists explore use of this test as a valid tool to assess players' performance and the effectiveness of training interventions.

Validity of a basketball-specific complex test in female professional players.

The purpose of this study was to assess the validity of a new basketball-specific complex test (BBCT) based on the ascertained match performance.Fourteen female professional basketball players (ages: 23.4 ±â€Š1.8 years) performed the BBCT and a treadmill test (TT) at the beginning of pre-season training. Lactate, heart rate (HR), time, shooting precision and number of errors were measured during the four test sequences of the BBCT (short distance sprinting with direction changes, with and without a ball; fast break; lay-up parcours; sprint endurance test). In addition, lactate threshold (LT) and HR were assessed at selected times throughout the TT and the BBCT and over 6 (TT) or 10 (BBCT) minutes after the tests. The match performance score (mps) was calculated on specific parameters (e. g. points) collected during all matches during the subsequent season (22 matches). The mps served as the "gold standard" within the validation process for the BBCT and the TT.TT parameters demonstrated an explained variance (EV) between 0 % (HR recovery) and 11 % (running speed at 6 mmol/l LT). The EV from the BBCT was higher and ranged from 0 % (HR recovery 6 minutes after end of exercise) to 28 % (sprint endurance test after 8 of 10 sprints). Ten out of 21 BBCT parameters (48 %) and 2 out of 5 TT parameters (40 %) demonstrated an EV higher than 10 %. Average EV for all parameters was 12 % (BBCT) and 6 % (TT), respectively. The BBCT had a higher validity than the TT for predicting match performance. These findings suggest that coaches and scientists should consider using the BBCT testing protocol to estimate the match performance abilities of elite female players.

Pre- and postoperative postural regulation following anterior cruciate ligament reconstruction.

There are currently no longitudinal data describing the pre- and postoperative postural regulation and stability of patients with anterior cruciate ligament (ACL) damage. Therefore, the aim of this study was to evaluate postural regulation and stability prior to and during rehabilitation following surgery of the ACL. Fifty-four physically active subjects (age: 30.5±10.9 years, 29 male subjects) were examined with the Interactive Balance System pre-, 6, and at 12 weeks following surgical reconstruction of the ACL using a hamstring tendon graft. The average period of time from injury to surgery was 27 days. Data were calculated with unifactorial and univariate analysis of variance. Significant effects were found for the somatosensory system (η2=0.115), stability indicator (η2=0.123), weight distribution index (η2=0.176), and synchronization (foot coordination) (η2=0.249). Involved side weight distribution (parameter: left) increased significantly (patients with left-sided/right-sided injury: η2=0.234/0.272). Load distribution to the heel remained stable during all three examination periods (η2=0.035 and η2=0.071), although a remarkable load at forefoot was observed. In seven out of 10 parameters partial effects were seen during the first 6 weeks after surgery. The results of this study indicated that injury of the ACL and subsequent surgical reconstructions result in postural regulation, with improvements in somatosensory system function, postural stability, weight distribution index, and foot coordination. Also, overloading of the injured side on the feet reduces significantly during rehabilitation. Thus, the initial phase of rehabilitation (weeks 1 to 6) seems to be more effective than the second period (weeks 6 to 12) postoperatively.

Relationships between the handball-specific complex test, non-specific field tests and the match performance score in elite professional handball players.

BACKGROUND: This study assessed the validity of the handball-specific complex test (HBCT) and two non-specific field tests in professional elite handball athletes, using the match performance score (MPS) as the gold standard of performance. METHODS: Thirteen elite male handball players (age: 27.4±4.8 years; premier German league) performed the HBCT, the Yo-Yo Intermittent Recovery (YYIR) test and a repeated shuttle sprint ability (RSA) test at the beginning of pre-season training. The RSA results were evaluated in terms of best time, total time, and fatigue decrement. Heart rates (HR) were assessed at selected times throughout all tests; the recovery HR was measured immediately post-test and 10 minutes later. The match performance score was based on various handball specific parameters (e.g., field goals, assists, steals, blocks, and technical mistakes) as seen during all matches of the immediately subsequent season (2015/2016). RESULTS: The parameters of run 1, run 2, and HR recovery at minutes 6 and 10 of the RSA test all showed a variance of more than 10% (range: 11-15%). However, the variance of scores for the YYIR test was much smaller (range: 1-7%). The resting HR (r2=0.18), HR recovery at minute 10 (r2=0.10), lactate concentration at rest (r2=0.17), recovery of heart rate from 0 to 10 minutes (r2=0.15), and velocity of second throw at first trial (r2=0.37) were the most valid HBCT parameters. CONCLUSIONS: Much effort is necessary to assess MPS and to develop valid tests. Speed and the rate of functional recovery seem the best predictors of competitive performance for elite handball players.

Short-Term Effects of Combined High-Intensity Strength and Sprint Interval Training on Anthropometric Characteristics and Physical Performance of Elite Team Handball Players.

Muscular strength and speed are critical physical factors in determining the technical and tactical skills of elite team handball players. This study thus investigated the effect of high-intensity muscular strength and sprint interval training (SIT) on lower limb explosive performance and anthropometric characteristics in 22 male handball athletes aged 20.2 ±â€Š0.1 years. A training group (TG, n = 12) and a control group (CG, n = 10) were followed over 8 weeks parallel to regular handball training. The TG received combined additional high-intensity muscular strength and interval training twice per week during this period. The muscular training was comprised of 3 - 4 sets of 70 - 85 % of 1-RM (repetition maximum) of dynamic back half squat exercise; followed immediately by a short sprint program with 4, 5, and 6 maximal intensity repetitions of 30 m runs. Strength (1-RM of the half back-squat and bench press), first step (V1S), first 5 m (V5 m), squat jumps (SJ), counter movement jumps (CMJ) and the Modified Agility Test (MAT) were tested at the beginning and end of the study. Significant interaction effects (group × time) were observed for all parameters (η² range: 0.531 (MAT) to 0.829 (First 5 m)). All 10 parameters showed relevant intervention effects (d> 0.5) in the TG (highest intervention effect: CMJ: d = 4.05), the mean effect size being d = 1.85. In contrast, scores for the CG either remained unchanged or decreased (d = -0.24). We conclude that combined high-intensity strength and sprint interval training during the competitive season should be recommended to elite male handball players as a means of improving handball-related performance characteristics without compromising other critical aspects of the individual's performance.