Lower extremity movement quality in professional team sport athletes: Inter-rater agreement and relationships with quantitative results from the corresponding pattern.

BACKGROUND: Adequate movement control and quality can be prerequisite functions for performance of the lower extremity. The purposes of our work were 1) to explore the agreement of an efficient test battery assessing qualitative movement execution and 2) to determine its consistency with quantitative performance tests from the corresponding movement pattern. METHODS: The participants were professional male association football players competing in the first German Bundesliga. They performed four movement quality tests (Single-limb balance squat, Balance forward hop, Balance side hop, Balance 90° rotation hop) and the corresponding performance tests (Y-balance test, Forward hop for distance, Side hop test, Square hop test). Qualitative tests were judged by two experienced raters; the ratings were compared to determine inter-rater agreement using Kappa statistics. The relationship with the quantitative tests was determined using Spearman's rank correlations. RESULTS: Thirty participants (19 to 33 years old) were included in this study. We found an at least substantial level of agreement (Cohen's Kappa, 0.64-0.84) with an excellent percentage of exact (83-93%) agreement between the two raters for the movement quality tests. Our findings revealed that the quantitative test results are only slightly related to the movement quality outcomes (ρ(27) <|0.3| and P > 0.2). CONCLUSIONS: Consequently, the qualitative test results provide unique information and complement corresponding quantitative performance tests in professional football athletes. Their observational judgement of foot position, lower limb alignment and upper body control in sagittal, frontal, and transverse planes is agreeable.

Muscle activity and rehabilitation in spinal stenosis (MARSS) after conservative therapy and surgical decompression with or without fusion: Protocol for a partially randomized patient preference trial on rehabilitation timing.

Background: Patients affected by lumbar spinal stenosis (LSS) suffer from a multifactorial degeneration of the lumbar spine resulting in narrowing of the neuroforamina and spinal canal, leading to various functional limitations. It remains unclear whether LSS patients after surgery would benefit from early post-operative rehabilitation, or if a delayed rehabilitation would be more advantageous. The purpose of this partially randomized patient preference trial is to evaluate the impact of post-operative rehabilitation timing as well as surgical intervention type on psychometric properties and functional outcomes in patients with LSS. Methods: Data for this patient preference trial are collected before and after surgical (decompression only or decompression and fusion) and rehabilitative interventions as well as six, 12 and 24 months after completing rehabilitation. The study participants are patients diagnosed with LSS who are at least 18 years old. After a medical check-up, participants will complete patient-reported outcome measures (PAREMO-20, SIBAR, FREM-8, SF-12, SFI, ODI) and different functional assessments (functional reach test, loaded reach test, handgrip strength, standing balance control, 6-min walk test). Ethics and dissemination: The results of this study will be published through peer-reviewed publications and scientific contributions at national and international conferences. This research has been approved by the Institutional Review Board of Martin Luther University Halle-Wittenberg (reference number: 2022-128).

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.

Feasibility, Reliability, and Validity of the Modified Forward Hop Test After Anterior Cruciate Ligament Reconstruction: Double- Instead of Single-legged Landing is Reliable and Results in Greater Hopping Distance.

OBJECTIVE: To investigate the feasibility, reliability, and validity of the Modified forward hop (MFH) test in participants after ACL reconstruction (ACLR). DESIGN: Reliability study. SETTING: Assessments were administered at different clinical locations in Germany and Switzerland by the same 2 investigators. PARTICIPANTS: Forty-eight active individuals participated in this study (N=48). MAIN OUTCOME MEASURES: The participants performed MFHs and Forward hops for distance in a predetermined order. The feasibility of the MFH was quantified with proportions of successfully executed attempts and Pearson's χ2 test. Its reliability was estimated using intraclass correlation coefficient (ICC) and standard error of measurement (SEM). Test validity was explored using Pearson's product moment correlation analyses. RESULTS: Fewer failed attempts were recorded among the participants (age: 30 [Standard deviation 11] years; 22 women, 26 (13) months post-surgery) when compared with the Forward hop for distance test (25/288 trials; 9% vs 72/288 trials; 25%). Within-session ICC values were excellent (>0.95) for both types of Forward hop tests, independent of the side examined. The SEM values were comparable between the Modified (injured: 5.6 cm, uninjured: 5.9 cm) and the classic Forward hop (injured: 4.3 cm, uninjured: 7.2 cm). CONCLUSION: The MFH is a feasible, reliable, and valid tool for judging neuromuscular performance after ACLR. If the aim of a hop for distance incorporates enhanced perceived or real landing safety, landing on both feet should be used.

[Return to throwing sports after upper extremity injury and overuse : A criteria-based approach using an ulnar collateral ligament injury as an example]. / Zurück zum Wurfsport nach Verletzung und Überlastung an der oberen Extremität : Ein kriterienbasierter Ansatz am Beispiel einer Verletzung des Ligamentum collaterale ulnare.

BACKGROUND: Uniform procedures for rehabilitation and follow-up treatment after injuries and surgeries at the upper extremity do not exist. Accordingly, only a few approaches for the follow-up treatment of instabilities of the elbow joint have been described. OBJECTIVES: The authors show how rehabilitation before sport-specific training after rupture of the ulnar collateral ligament in a female handball player was objectivized and controlled using the results of functional tests. MATERIALS AND METHODS: The follow-up treatment of a semi-professional female handball player (aged 20) after rupture of the ulnar collateral ligament was objectivized and controlled using the return to activity algorithm. In addition to the comparisons with the values of the unaffected side, comparative results of 14 uninjured female handball players were used for guidance. RESULTS/CONCLUSIONS: The patient was able to participate fully in sport-specific training after 15 weeks and participate in her first competitive match after 20 weeks. On the affected side, she achieved a distance of 118% of her upper limb length on the medial reach of the upper quarter Y balance test and 63 valid contacts on the wall hop test. The values achieved at the end of rehabilitation were higher than the average values of the control group.

Assessment of return to play after an acute shoulder injury: protocol for an explorative prospective observational German multicentre study.

INTRODUCTION: To date, there is no valid single test or battery of tests for informing return-to-play (RTP) decisions following an acute shoulder injury. The purpose of this exploratory study is to evaluate a diagnostic test battery based on a Delphi consensus at the time of unrestricted return to team training after acute shoulder injury. METHODS AND ANALYSIS: Data for this prospective multicentre cohort study are collected at two measurement time points: when the respective physician clears the patient for RTP (t1) and 12 months after RTP (t2). The study participants are 18-35 years old athletes participating at a professional level in the following team sports: handball, basketball, ice hockey, soccer, volleyball and American football. Maximum comparability will be ensured via uninjured matched pair teammates. To assess the subjective assessment of shoulder functioning and the athlete's readiness to RTP, patient-reported outcome measures (Western Ontario Shoulder Instability Index, Quick-Disabilities of the Arm, Shoulder and Hand, Psychological Readiness of Injured Athlete to Return to Sport and Shoulder Instability-Return to Sport after Injury) will be completed. After a medical check-up with a range of motion and anthropometric measurements as well as clinical tests, the participants will perform a structured warm-up protocol. The functional tests comprise handgrip strength, upper quarter Y-balance test, isometric strength, closed kinetic chain upper extremity stability test, wall hop test, functional throwing performance index and the unilateral seated shot put test and isokinetic tests. ETHICS AND DISSEMINATION: The results of this study will be disseminated through peer-reviewed publications and scientific presentations at national and international conferences. Ethical approval was obtained through the Institutional Review Board of Martin-Luther-University Halle-Wittenberg (reference number: 2022-016). TRIAL REGISTRATION NUMBER: DRKS00028265.

Effects of Different Orthoses on Neuromuscular Activity of Superficial and Deep Shoulder Muscles during Activities of Daily Living and Physiotherapeutic Exercises in Healthy Participants.

BACKGROUND: This study aimed to investigate the effects of different shoulder orthoses on the neuromuscular activity of superficial and deep shoulder muscles during activities of daily living (ADL) and physiotherapeutic exercises. METHODS: Ten participants with healthy shoulders (31 ± 3 years, 23.1 ± 3.8 kg/m2) were randomized to receive a "shoulder sling", an "abduction pillow" and a "variably adjustable orthosis" on the dominant side. With each orthosis, they completed seven ADL with and four physiotherapeutic exercises without wearing the orthoses. An electromyographic system was used to record the neuromuscular activity of three superficial (trapezius, deltoid, pectoralis major) and two deep shoulder muscles (infraspinatus, supraspinatus) using surface and intramuscular fine-wire electrodes. RESULTS: The neuromuscular activity differs between the orthoses during ADL (p ≤ 0.045), whereby the "variably adjustable orthosis" mostly showed the highest activation levels associated with the worst subjective wearing comfort rated on a visual analog scale. In addition, differences exist between the physiotherapeutic exercises (p ≤ 0.006) demonstrating the highest activations of the infra- and supraspinatus muscles for assistive elevation and wipe across a table, middle for pendulum and lowest for continuous passive motion exercises. CONCLUSIONS: The neuromuscular activity of superficial and deep shoulder muscles differs between the orthoses during ADL and also between the physiotherapeutic exercises.

Standing Steadiness and Asymmetry after High Tibial Osteotomy Surgery: A 2 Year Follow-Up Study.

(1) Background: Knee osteoarthritis (OA) is a serious orthopedic problem. In this context, the high tibial osteotomy (HTO) is an established surgical procedure to reduce the load and degeneration of the affected compartment. The aim of this investigation was to judge standing steadiness and asymmetry, pain intensity and quality of life among patients who underwent HTO surgery. (2) Methods: Twenty-five male patients with medial tibiofemoral OA finished this 2 year follow-up study. Standing balance was captured using force plates with four uniaxial sensors before, 6 weeks after, 1 year after, and 2 years after HTO surgery. The percentage weight (PW) under the foot at one side, the stability (ST) index and the weight distribution (WD) index were the main outcomes. Comparisons were conducted using repeated measures analyses of variance. (3) Results: Over time, the PW under the foot at the HTO side increased on average (p < 0.001). In terms of standing steadiness, the average ST remained similar over the time points (p = 0.71). The WD index was affected by time (p = 0.003). (4) Conclusions: In order to judge short-term effects, the PW is recommended, whereas long-term effects can be identified either through the PW or the WD index.

Foot tapping and unilateral vertical jump performance in athletes after knee surgery: an explorative cross-sectional study.

BACKGROUND: Guiding athletes through the rehabilitation process and judging the time at which return to sports can be enabled after anterior cruciate ligament (ACL) injuries are still challenging processes. The purpose of this explorative cross-sectional study was to retrospectively compare unilateral vertical jump as well as vertical foot tapping outcomes in athletes returned to sports after ACL reconstruction (ACLR) with uninjured athletes. METHODS: Seven-teen ACLR athletes (male/female: 12/5) were examined 11 (6-23) months after their ACL injury and after return to sport clearance together with 67 uninjured athletes (male/female: 51/16). Seventeen age and stature matched controls were selected from the sample of uninjured athletes. Participants unilaterally performed acyclic (squat jump, SJ; drop jump, DJ) and cyclic (foot tapping, FT) tests. SJ peak power, DJ take-off efficiency (TOE) and FT coefficients (FTC) were compared between ACLR and matched as well as unmatched control groups. Limb symmetry index (LSI) as well as performance score were calculated. RESULTS: Analyses of the SJ peak power revealed moderate effects of group (right: P < 0.09, ηp2 = 0.06; left: P < 0.05, ηp2 = 0.08). The TOE was largely affected by group (right: P < 0.01, ηp2 = 0.12; left: P < 0.01, ηp2 = 0.13). No effect of group was found on the FTC (P > 0.8, ηp2 < 0.01). The SJ peak power LSI (r = 0.46, P < 0.07) and TOE LSI (r = 0.38, P = 0.13) were positively associated with the performance score of the ACLR group. CONCLUSION: Although already returned to sports, the ACLR group underperformed the matched and unmatched control groups significantly. Unilaterally performed vertical jumps may provide additional information on athletes' rehabilitation progress and help to manage the rehabilitation process and decisions on potential readiness after ACLR. More attention should be paid to the direction of the LSI results.

[Judging movement quality in patients who sustained a knee ligament injury: a systematic review]. / Tests zur Beurteilung der Bewegungsqualität nach ligamentären Verletzungen des Kniegelenks: eine systematische Übersichtsarbeit.

BACKGROUND: Knee joint injury statistics are dominated by ruptures of the capsular ligament structures. Post-traumatic deficits in dynamic movement patterns are assessed quantitatively as well as qualitatively. The aim of this review was to compile tools that are used to assess the quality of movement after knee ligament injuries in adults. METHODS: A systematic search for original papers was carried out in the following primary sources: Ovid, PubMed, Scopus and Web of Science. Both conservative and surgical treatment options were considered. PROSPERO registration of the study protocol: CRD42020175359. RESULTS: A total of 1153 papers were identified. Eleven original papers from four different working groups were included in this work. All papers assessed the quality of movement in adults after anterior cruciate ligament (ACL) injury. A total of 348 (70 deficient, 278 reconstructed) patients after an ACL injury and 119 adults with an intact ACL were examined in the studies included. CONCLUSION: It is possible to assess movement quality after a knee ligament injury with a low temporal and technical effort. The changes recorded result in a functional valgus, which, based on the study results, may be further differentiated into isolated knee valgus, medial collapse or postural collapse.

[Function-based tests to determine the return-to-activity state in patients with non-specific low back pain]. / Funktionelle Testungen zur Ermittlung des Return-to-Activity-Status bei Patienten mit unspezifischen Kreuzschmerzen.

BACKGROUND: Most people with back pain suffer from non-specific low back pain, for which no specific reasons can be found. Two out of three have recurrent pain episodes. To reduce the likelihood of recurrence and long-lasting pain, functional tests are increasingly used to determine the current functional status. This literature study evaluates evidence of functional tests in patients with non-specific low back pain and their validity related to the return-to-activity (RTA) status. The objective of this analysis is to give recommendations for specific activities and to assess the risk of chronification and recurrent pain. METHODS: PubMed-based literature search. Narrative review focusing on data from the past ten years. RESULTS: A total of twelve studies were included in the analysis. Overall, 33 different tests were identified for which positive statements regarding reliability, validity and relevance for the assessment of the RTA status in non-specific back pain could be made. The tests identified may be able to provide useful information when assessing the RTA status and to recognise yellow and blue flags in patients with non-specific low back pain. The ability to walk, the behaviour when lifting and carrying objects, motor control, muscle strength and mobility play a particular role. CONCLUSION: The determination of the RTA status in patients with non-specific low back pain should be patient-specific and based on biopsychosocial aspects rather than relying exclusively on movement-related tests. Exact statements regarding the point in time when patients can resume everyday activities and work without an increased risk of recurrence or chronicity do not seem possible with functional tests alone. The major influence of psychological and social factors on disease development, course and prognosis are limiting factors. Movement and strain-related tests can still be used to evaluate activities related to everyday life, to design therapy programs and to give patients confidence.

Effects of Hip Flexion on Knee Extension and Flexion Isokinetic Angle-Specific Torques and HQ-Ratios.

BACKGROUND AND METHODS: During isokinetic knee strength testing, the knee flexion angles that correspond to the measured torque values are rarely considered. Additionally, the hip flexion angle during seated testing diverges from that in the majority of daily life and sporting activities. Limited information concerning the influence of hip angle, muscle contraction mode, and velocity on the isokinetic knee strength over the entire range of motion (ROM) is available. Twenty recreational athletes (10 females, 10 males; 23.3 ± 3.2 years; 72.1 ± 16.5 kg; 1.78 ± 0.07 m) were tested for isokinetic knee flexion and extension at 10° and 90° hip flexion with the following conditions: (i) concentric at 60°/s, (ii) concentric at 180°/s, and (iii) eccentric at 60°/s. The effects of hip angle, contraction mode, and velocity on angle-specific torques and HQ-ratios as well as conventional parameters (peak torques, angles at peak torque, and HQ-ratios) were analyzed using statistical parametric mapping and parametric ANOVAs, respectively. RESULTS: Generally, the angle-specific and conventional torques and HQ-ratios were lower in the extended hip compared to a flexed hip joint. Thereby, in comparison to the knee extension, the torque values decreased to a greater extent during knee flexion but not consistent over the entire ROM. The torque values were greater at the lower velocity and eccentric mode, but the influence of the velocity and contraction mode were lower at shorter and greater muscle lengths, respectively. CONCLUSIONS: Isokinetic knee strength is influenced by the hip flexion angle. Therefore, a seated position during testing and training is questionable, because the hip joint is rarely flexed at 90° during daily life and sporting activities. Maximum knee strength is lower in supine position, which should be considered for training and testing. The angle-specific effects cannot be mirrored by the conventional parameters. Therefore, angle-specific analyses are recommended to obtain supplemental information and consequently to improve knee strength testing.

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.

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.

Comparison of posturographic outcomes between two different devices.

The Interactive Balance System (IBS), a posturography device for assessing posture control, is widely used in clinical and rehabilitation settings. However, data on the validity of the device are unavailable. Fluctuations of the center of pressure (COP) were measured in 24 healthy participants (age: 29 ±â€¯5 (mean ±â€¯SD) years, 12 females) synchronously using the IBS, which was rigidly mounted on a Kistler platform. Four different bipedal conditions were examined: eyes open or closed on stable or soft surfaces. Time series were compared using congruity (CON, proportion of the measurement time during which values of both devices changed similarly in direction), whereas IBS-specific postural outcomes were correlated with traditional postural control outcomes of the Kistler force platform. The time-displacement curves showed similar shapes for CON (>0.9) for each of the four standing conditions without differences between male and female participants (P > 0.39). The path length results of both devices showed very high linear associations, explaining on average 92% (medio-lateral) or 96% (anterior-posterior) of the common variance. The Kistler path length of the anterior-posterior direction revealed nearly perfect linear associations with the stability index of the IBS (r2 > 0.99). The results of this study indicate that the IBS provides valid posturographic results. Since the medial-lateral and anterior-posterior trajectories of the IBS can be used to calculate COP fluctuations, comparisons between different measurement systems are possible.

Posturographic and ankle muscle activation characteristics in patients with haemophilia.

INTRODUCTION: The objective of this work was to examine the interrelations of posturographic and surface EMG (SEMG) characteristics of ankle muscles in patients with haemophilia while standing naturally. METHODS: Surface EMG of five bilaterally recorded ankle muscles was conducted in 24 patients with haemophilia (PwH, age: 42 [11] years, mean [SD], 22 A, 2 B, 21 severe, 3 moderate) with median (quartiles) WFH orthopaedic joint score of 30 (20/39) points and 24 non-haemophilic controls (Con, age: 42 [12]). Force plate (IBS) signals were captured simultaneously during bipedal stance with eyes open. Load proportion of the left and right sides as well as heel and forefoot were calculated via four independent pressure transducers. Overall, weight distribution (WD) indices are reported with higher results representing a poorer WD. RESULTS: Analyses of WD showed large differences between groups (PwH: 10.2 [5.4], Con: 5.2 [2.9], P < 0.001, d = 1.15). After clustering PwH, large effects (P = 0.02, ηp 2  > 0.16) were found for amplitude ratios of the lateral gastrocnemius (LG) muscle. In PwH, the degree of joint alteration of the right lower limb was associated with load proportion of the left side (ρ > 0.64, P = 0.001). CONCLUSION: Patients with greater dysbalance showed higher forefoot loads and appeared to compensate their altered joint situations with considerably higher amplitude ratios of LG. Further studies should investigate whether therapeutic interventions could alter postural alignment and muscle activation and how these can influence patients' joint function and symptoms.

[Risk screening in handball: Which functional tests are useful?] / Risiko-Screening im Handballsport ­ Welche funktionellen Tests sind sinnvoll?

BACKGROUND: Applying functional tests in sports is one way to optimise injury prevention. Based on the results, corrective exercises may be recommended to address deficits. The aim of this study was to compare the results of selected functional tests with the occurrence of injuries in young handball players. MATERIAL AND METHODS: Thirty-one players from youth teams of a Handball Bundesliga club participated in this study. In the run-up to the second half of the season, all players completed the Functional Movement Screen, the Y-balance test, front hop, side hop and square hop tests. All injuries that occurred after the tests were recorded until the end of the season. RESULTS: Within the investigation period, four non-contact and four contact injuries occurred. Players with non-contact injuries performed the side hop test with a limb symmetry index of 78 % (uninjured players and players with contact injuries: > 85 %) and the Y-balance test with a composite score of 87 % (uninjured players and players with contact injuries: > 90 %). Results of the Functional Movement Screen, the front and square hop tests did not differ between injured and uninjured players. CONCLUSION: The results of this study suggest that functional test batteries in handball should consider low-threshold as well as high-threshold tests. Based on this experience, the Y-balance test and the side hop test seem to be particularly suitable for handball athletes.

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.