Anterior cruciate ligament injuries in elite ski jumping reliably allow return to competition but severely affect future top performance.

PURPOSE: In recent years, anterior cruciate ligament (ACL) injuries have been frequently observed in ski jumping. However, available data in this discipline are very scarce. Therefore, the purpose of this study was to investigate whether an ACL injury in elite-level ski jumping limits the performance level after ACL reconstruction (ACLR). METHODS: Both male and female elite-level ski jumpers from five national A-teams who suffered an ACL injury were identified retrospectively by searching available media reports and Fédération Internationale de Ski (FIS) database. World Cup (WC) results and time-out-of-competition before ACL injury and after ACLR were compared. Only athletes who suffered the injury during or after the 2009-2010 season and who participated in at least one WC competition before the injury were included in this study. The level of athletes' performance from two full seasons before until three seasons after the injury was compared. RESULTS: Eighteen elite-level ski jumpers (11 males/seven females) were eligible for the study. All male and four female athletes returned to professional competition after ACLR. One female athlete ended her career due to prolonged recovery and two have not yet recovered due to a recent injury. The mean return-to-competition (RTC) time was 14.6 months in males and 13.5 months in females. The mean WC placement decreased after the ACL injury: two seasons before injury the mean position was 17.9 ± 11.0 (n = 12), one season before it was 22.4 ± 12.8 (n = 15). After recovery, the mean placement in seasons 1-3 was: 26.4 ± 8.9 (n = 7), 25.7 ± 10.3 (n = 13), 33.6 ± 12.2 (n = 10) (p = 0.008). Among the athletes returning to competition, only six males and three females reached their preinjury level and only one male and one female (compared to seven males and three females preinjury) reached an individual top-3 placement after ACLR, accounting for less than 10% of podiums compared to preinjury. CONCLUSION: Only 60% of the professional ski jumpers reached the preinjury level and less than 15% reached a top-3 placement after the ACL injury. These results support the fact that ACL tear during a ski jumping career may be a significant factor limiting high-level performance. In terms of clinical relevance, the findings implicate the need to analyse the reasons of these very low rates of return to elite-level performance, to analyse ACL injury and RTC rates at lower levels of performance and to develop specific prevention strategies in order to reduce the number of ACL injuries in this sport. LEVEL OF EVIDENCE: Level IV.

The awareness of injury prevention programmes is insufficient among French- and German-speaking sports medicine communities in Europe.

PURPOSE: Evaluate the current state of sports injury prevention perception, knowledge and practice among sports medicine professionals located in Western Europe and involved in injury prevention. METHODS: Members of two different sports medicine organizations (GOTS and ReFORM) were invited to complete a web-based questionnaire (in German and in French, respectively) addressing perception, knowledge and implementation of sports injury prevention through 22 questions. RESULTS: 766 participants from a dozen of countries completed the survey. Among them, 43% were surgeons, 23% sport physicians and 18% physiotherapists working mainly in France (38%), Germany (23%) and Belgium (10%). The sample rated the importance of injury prevention as "high" or "very high" in a majority of cases (91%), but only 54% reported to be aware of specific injury prevention programmes. The French-speaking world was characterized by lower levels of reported knowledge, unfamiliarity with existing prevention programmes and less weekly time spent on prevention as compared to their German-speaking counterparts. Injury prevention barriers reported by the respondents included mainly insufficient expertise, absence of staff support from sports organizations and lack of time. CONCLUSION: There is a lack of awareness regarding injury prevention concepts among sports medicine professionals of the European French- and German-speaking world. This gap varied according to the professional occupation and working country. Relevant future paths for improvement include specific efforts to build awareness around sports injury prevention. LEVEL OF EVIDENCE: Level IV.

Functional Mobility and Dynamic Postural Control Predict Overhead Handball Throwing Performance in Elite Female Team Handball Players.

The relationship between dynamic postural control, functional mobility and team handball throwing performance, velocity and accuracy, is largely unknown. The hand reach star excursion balance test (HSEBT) is a full kinetic chain assessment tool of these factors. Specifically, L135 and R135 (extension) reaches elicit joint movement combinations similar to the cocking and acceleration phase, while the L45 and R45 (flexion) reaches elicit joint movement combinations similar to the follow-through. The purpose of this study was to determine if specific HSEBT reach measures correlate with team handball throwing performance. Eleven elite female team handball players (21.7 ± 1.8 years; 71.3 ± 9.6 kg; 1.75 ± 0.07 m) executed selected HSEBT reaches before performing five valid step-up overhead throws (1x1m target) from which throwing velocity (motion capture) and accuracy (mean radial error) were quantified. Significant relationships between HSEBT measures and mean radial error, but not throwing velocity were established. Specifically, extension composite scores (L135+R135) for the dominant (150.7 ± 17.4cm) and non-dominant foot (148.1 ± 17.5 cm) were correlated with mean radial error (p < 0.05). Also, specific reaches on the dominant (L135: 87.4 ± 5.6 cm; R135: 63.4 ± 11.8 cm) and non-dominant (R135: 87.0 ± 6.1 cm) foot were correlated with throwing error (p < 0.05). The lack of significant findings to throwing velocity might be due to a ceiling effect of both L135 and R135 and of throwing velocity. We conclude that while there may be other reasons for handball players to train and test functional mobility and dynamic postural control as measured in the HSEBT, no beneficial effect on throwing performance should be expected in an elite group of handball players.

Muscle coordination, activation and kinematics of world-class and elite breaststroke swimmers during submaximal and maximal efforts.

The aims of this study were to describe muscular activation patterns and kinematic variables during the complete stroke cycle (SC) and the different phases of breaststroke swimming at submaximal and maximal efforts. Surface electromyography (sEMG) was collected from eight muscles in nine elite swimmers; five females (age 20.3 ± 5.4 years; Fédération Internationale de Natation [FINA] points 815 ± 160) and four males (27.7 ± 7.1 years; FINA points 879 ± 151). Underwater cameras were used for 3D kinematic analysis with automatic motion tracking. The participants swam 25 m of breaststroke at 60%, 80% and 100% effort and each SC was divided into three phases: knee extension, knee extended and knee flexion. With increasing effort, the swimmers decreased their SC distance and increased their velocity and stroke rate. A decrease during the different phases was found for duration during knee extended and knee flexion, distance during knee extended and knee angle at the beginning of knee extension with increasing effort. Velocity increased for all phases. The mean activation pattern remained similar across the different effort levels, but the muscles showed longer activation periods relative to the SC and increased integrated sEMG (except trapezius) with increasing effort. The muscle activation patterns, muscular participation and kinematics assessed in this study with elite breaststroke swimmers contribute to a better understanding of the stroke and what occurs at different effort levels. This could be used as a reference for optimising breaststroke training to improve performance.

Muscle coordination during breaststroke swimming: Comparison between elite swimmers and beginners.

The present study aimed to compare muscle coordination strategies of the upper and lower limb muscles between beginners and elite breaststroke swimmers. Surface electromyography (EMG) of eight muscles was recorded in 16 swimmers (8 elite, 8 beginners) during a 25 m swimming breaststroke at 100% of maximal effort. A decomposition algorithm was used to identify the muscle synergies that represent the temporal and spatial organisation of muscle coordination. Between-groups indices of similarity and lag times were calculated. Individual muscle patterns were moderately to highly similar between groups (between-group indices range: 0.61 to 0.84). Significant differences were found in terms of lag time for pectoralis major (P < 0.05), biceps brachii, rectus femoris and tibialis anterior (P < 0.01), indicating an earlier activation for these muscles in beginners compared to elites (range: -13.2 to -3.8% of the swimming cycle). Three muscle synergies were identified for both beginners and elites. Although their composition was similar between populations, the third synergy exhibited a high within-group variability. Moderate to high indices of similarity were found for the shape of synergy activation coefficients (range: 0.63 to 0.88) but there was a significant backward shift (-8.4% of the swimming cycle) in synergy #2 for beginners compared to elites. This time shift suggested differences in the global arm-to-leg coordination. These results indicate that the synergistic organisation of muscle coordination during breaststroke swimming is not profoundly affected by expertise. However, specific timing adjustments were observed between lower and upper limbs.

Influence of short-term unweighing and reloading on running kinetics and muscle activity.

PURPOSE: In running, body weight reduction is reported to result in decreased lower limb muscle activity with no change in the global activation pattern (Liebenberg et al. in J Sports Sci 29:207-214). Our study examined the acute effects on running mechanics and lower limb muscle activity of short-term unweighing and reloading conditions while running on a treadmill with a lower body positive pressure (LBPP) device. METHOD: Eleven healthy males performed two randomized running series of 9 min at preferred speed. Each series included three successive running conditions of 3 min [at 100 % body weight (BW), 60 or 80 % BW, and 100 % BW]. Vertical ground reaction force and center of mass accelerations were analyzed together with surface EMG activity recorded from six major muscles of the left lower limb for the first and last 30 s of each running condition. Effort sensation and mean heart rate were also recorded. RESULT: In both running series, the unloaded running pattern was characterized by a lower step frequency (due to increased flight time with no change in contact time), lower impact and active force peaks, and also by reduced loading rate and push-off impulse. Amplitude of muscle activity overall decreased, but pre-contact and braking phase extensor muscle activity did not change, whereas it was reduced during the subsequent push-off phase. CONCLUSION: The combined neuro-mechanical changes suggest that LBPP technology provides runners with an efficient support during the stride. The after-effects recorded after reloading highlight the fact that 3 min of unweighing may be sufficient for updating the running pattern.

Reliability and validity of PedsQL for Portuguese children aged 5-7 and 8-12 years.

BACKGROUND: Pediatric Quality of Life Inventory (PedsQL) is a measure to assess health-related quality of life (HRQoL) in children and adolescents. It is formed by 23 items adapted to children age and includes a parent proxy report version. With four multidimensional subscales and three summary scores, it measures health as defined by WHO. The concepts measured by this instrument are 'physical functioning' (8 items), 'emotional functioning' (5 items), 'social functioning' (5 items) and 'school functioning' (5 items). It also measures a 'total scale score' (23 items), a 'physical health summary score' (8 items) and a 'psychosocial health summary score' (15 items). The aim of this paper is to present the main results of the cultural adaptation and validation of the PedsQL into European Portuguese. METHODS: The Portuguese version was the result of a forward-backward translation process, with a cognitive debriefing analysis, guaranteeing face validity and semantic equivalence. Children aged 5-7 and 8-12 were randomly selected and were asked to fill a socio-demographic data survey and the Portuguese versions of PedsQL and KINDL, another HRQoL measure for children and adolescents. They were divided into three groups, healthy children, children with type I diabetes and children with spina bifida. RESULTS: A total of 179 children and 97 parents were recruited. PedsQL demonstrated good levels of reproducibility (r > 0.95 in all versions) and acceptable levels of internal consistency with Cronbach's alpha at 0.70 on most scales. Concordance values between children's and parents' perceptions ranged between 0.36 and 0.78 and the correlations with KINDL questionnaire were excellent, supporting concurrent validity. CONCLUSIONS: The Portuguese version of the PedsQL demonstrated acceptable psychometric properties for future research and clinical practice for children aged 5-12.

Gender differences in the kinematics and ball velocity of overarm throwing in elite team handball players.

The aim of this study was to investigate the throwing velocity and kinematics of overarm throwing in team handball of elite female and male handball players. Kinematics and ball velocity of a 7 metre-throw in eleven elite male (age 23.6 ± 5.2 yr, body mass 87.0 ± 6.8 kg, height 1.85 ± 0.05 m) and eleven elite female (age 20.3 ± 1.8 yr, body mass 69.9 ± 5.5 kg, height 1.75 ± 0.05 m) team handball players were recorded. The analysis consisted of maximal joint angles, angles at ball release, maximal angular velocities of the joint movements, and maximal linear velocities of the distal endpoints of segments and their timing during the throw. The ball release velocity of the male handball players was significantly higher than the females (21.1 vs. 19.2 m · s(-1); p < 0.05). No major differences in kinematics were found, except for the maximal endpoint velocities of the hand and wrist segment, indicating that male and female handball players throw with the same technique. It was concluded that differences in throwing velocity in elite male and female handball players are generally not the result of changes in kinematics in the joint movements.

Relevance of Frequency-Domain Analyses to Relate Shoe Cushioning, Ground Impact Forces and Running Injury Risk: A Secondary Analysis of a Randomized Trial With 800+ Recreational Runners.

Cushioning systems in running shoes are used assuming that ground impact forces relate to injury risk and that cushioning materials reduce these impact forces. In our recent trial, the more cushioned shoe version was associated with lower injury risk. However, vertical impact peak force was higher in participants with the Soft shoe version. The primary objective of this study was to investigate the effect of shoe cushioning on the time, magnitude and frequency characteristics of peak forces using frequency-domain analysis by comparing the two study groups from our recent trial (Hard and Soft shoe group, respectively). The secondary objective was to investigate if force characteristics are prospectively associated with the risk of running-related injury. This is a secondary analysis of a double-blinded randomized trial on shoe cushioning with a biomechanical running analysis at baseline and a 6-month follow-up on running exposure and injury. Participants (n = 848) were tested on an instrumented treadmill at their preferred running speed in their randomly allocated shoe condition. The vertical ground reaction force signal for each stance phase was decomposed into the frequency domain using the discrete Fourier transform. Both components were recomposed into the time domain using the inverse Fourier transform. An analysis of variance was used to compare force characteristics between the two study groups. Cox regression analysis was used to investigate the association between force characteristics and injury risk. Participants using the Soft shoes displayed lower impact peak force (p < 0.001, d = 0.23), longer time to peak force (p < 0.001, d = 0.25), and lower average loading rate (p < 0.001, d = 0.18) of the high frequency signal compared to those using the Hard shoes. Participants with low average and instantaneous loading rate of the high frequency signal had lower injury risk [Sub hazard rate ratio (SHR) = 0.49 and 0.55; 95% Confidence Interval (CI) = 0.25-0.97 and 0.30-0.99, respectively], and those with early occurrence of impact peak force (high frequency signal) had greater injury risk (SHR = 1.60; 95% CI = 1.05-2.53). Our findings may explain the protective effect of the Soft shoe version previously observed. The present study also demonstrates that frequency-domain analyses may provide clinically relevant impact force characteristics. Clinical Trial Registration: https://clinicaltrials.gov/, identifier: 9NCT03115437.

Trunk, pelvic and hip kinematics during the Stork test in pregnant women with pelvic girdle pain, asymptomatic pregnant and non-pregnant women.

BACKGROUND: Pelvic girdle pain is prevalent during pregnancy, and women affected report weight-bearing activities to be their main disability. The Stork test is a commonly used single-leg-stance test. As clinicians report specific movement patterns in those with pelvic girdle pain, we aimed to investigate the influence of both pregnancy and pelvic girdle pain on performance of the Stork test. METHODS: In this cross-sectional study, 25 pregnant women with pelvic girdle pain, 23 asymptomatic pregnant and 24 asymptomatic non-pregnant women underwent three-dimensional kinematic analysis of the Stork test. Linear mixed models were used to investigate between-group differences in trunk, pelvic and hip kinematics during neutral stance, weight shift, leg lift and single leg stance. FINDINGS: Few and small significant between-group differences were found. Pregnant women with pelvic girdle pain had significantly less hip adduction during single leg stance compared to asymptomatic pregnant women (estimated marginal means (95% confidence intervals) -1.1° (-2.4°, 0.3°) and 1.0° (-0.4°, 2.4°), respectively; P = 0.03). Asymptomatic pregnant women had significantly less hip internal rotation compared to non-pregnant women 4.1° (1.6°, 6.7°) and 7.9° (5.4°, 10.4°), respectively (P = 0.04) and greater peak hip flexion angle of the lifted leg in single leg stance 80.4° (77.0°, 83.9°) and 74.1° (70.8°, 77.5°), respectively (P = 0.01). Variation in key kinematic variables was large across participants in all three groups. INTERPRETATION: Our findings indicate that trunk, pelvic and hip movements during the Stork test are not specific to pregnancy and/or pelvic girdle pain in the 2nd trimester. Instead, movement strategies appear unique to each individual.

Influence of Anthropometry, Age, Sex, and Activity Level on the Hand Reach Star Excursion Balance Test.

The influence of anthropometric measurements, age, sex, and activity level have been found to influence tests of dynamic postural control such as the star excursion balance test (SEBT). The hand reach star excursion balance test (HSEBT) measures different aspects of dynamic postural control. The purpose of the present study was to explore the influence of these factors on the HSEBT. A convenience sample of 223 subjects performed four horizontal (L45, R45, L135, and R135) and two rotational (LROT and RROT) reaches. The influence of anthropometric measurements (height, arm length, leg length, and wingspan) on reach measurements were assessed using stepwise multiple linear regression. Influence of age (young: <20 years; adult: >20 years), sex (male; female) and activity level (athletes; recreational) on reach measurements were analyzed using independent samples t-test (p < 0.05) and interpreted using effect size (Cohens d) and established values of minimal detectable change (MDC). Wingspan explained a significant portion of the variance of only R45 (34.6%) and L45 (11.7%) reach measurements and normalized (percentage of wingspan). A medium effect of age, sex, and activity level was observed for normalized L45 and R45 reaches (d = 0.50-72). Group differences greater than MDC values and a medium effect for age (d = 0.55) and activity level (d = 0.75) were observed for the R135 reach. L45 and R45 reaches should be normalized to wingspan, but not the other reaches. Between individual or group comparisons should consider age, activity level and sex as potential covariates.

Isokinetic strength training of kinetic chain exercises of a professional tennis player with a minor partial internal abdominal oblique muscle tear - A case report.

OBJECTIVE: To present a case of a right-handed professional tennis player with a left internal abdominal oblique muscle tear sustained while serving. We document the progress of a rehabilitation program consisting of primarily kinetic chain isokinetic strength training where symmetrical measurements (<10% side difference) of force and dynamic postural control were used as criteria for return to sport. METHODS: Isokinetic exercises (bilateral rotational pull, unilateral vertical press and unilateral anterior push) to target trunk specific demands of the serve (flexion, rotation and lateral flexion) were done using robotic resistance. Dynamic postural control was assessed using the hand reach star excursion balance test (HSEBT). The rehabilitation program lasted 3.5 weeks (eight sessions). RESULTS: At baseline isokinetic strength tests that imposed concentric muscle function demands of the injured muscle had lower force measurements (range: -32.1 to -71.9%). These force measurements improved (range: 166.1-296.5%) and were symmetrical (range: +1.6 to +7.3%) on return to sport. In addition, the HSEBT test with the greatest asymmetry (-20 cm) improved to symmetrical (+2 cm) on return to sport. CONCLUSION: Symmetrical isokinetic force and dynamic postural control measurements were successful return to sport criteria as the player since has remained pain free (2 years).

SwimBIT: A Novel Approach to Stroke Analysis During Swim Training Based on Attitude and Heading Reference System (AHRS).

In a world where technology is assuming a pervasive role, sports sciences are also increasingly exploiting the possibilities opened by advanced sensors and intelligent algorithms. This paper focuses on the development of a convenient, practical, and low-cost system, SwimBIT, which is intended to help swimmers and coaches in performance evaluation, improvement, and injury reduction. Real-world data were collected from 13 triathletes (age 20.8 ± 3.5 years, height 173.7 ± 5.3 cm, and weight 63.5 ± 6.3 kg) with different skill levels in performing the four competitive styles of swimming in order to develop a representative database and allow assessment of the system's performance in swimming conditions. The hardware collects a set of signals from swimmers based on an attitude and heading reference system (AHRS), and a machine learning workflow for data analysis is used to extract a selection of indicators that allows analysis of a swimmer's performance. Based on the AHRS data, three novel indicators are proposed: trunk elevation, body balance, and body rotation. Experimental evaluation has shown promising results, with a 100% accuracy in swim lap segmentation, a precision of 100% in the recognition of backstroke, and a precision of 89.60% in the three remaining swimming techniques (butterfly, breaststroke, and front crawl). The performance indicators proposed here provide valuable information for both swimmers and coaches in their quest for enhancing performance and preventing injuries.

The Timed Up & Go test in pregnant women with pelvic girdle pain compared to asymptomatic pregnant and non-pregnant women.

BACKGROUND: The Timed Up and Go (TUG) test, a standardized functional mobility test, has been proposed as a physical performance-based measure in pregnant women with pelvic girdle pain (PGP). OBJECTIVES: This cross-sectional study aimed to investigate physical function by the use of TUG in pregnant women with PGP compared to asymptomatic pregnant and non-pregnant women, and to identify factors associated with increased TUG. METHODS: In total, 25 pregnant women with PGP, 24 asymptomatic pregnant and 25 asymptomatic non-pregnant women participated. One-way analysis of variance was used to explore difference in TUG between the groups and multiple linear regression analyses to explore associations between TUG and potential explanatory variables. RESULTS: The time on TUG varied among pregnant women with PGP, and was significantly higher (mean (95% CI) 6.9 (6.5, 7.3) seconds) than for asymptomatic pregnant (5.8 (5.5, 6.0), p < 0.001) and non-pregnant (5.5 (5.4, 5.6), p < 0.001) women. In the total study sample, group, increased BMI and sick leave were significantly associated with increased TUG (p-values≤0.02). In pregnant women with PGP, pain intensity was the only significant clinical factor associated with increased TUG (p = 0.002). CONCLUSION: Pregnant women with PGP used longer time and showed larger variation in TUG than asymptomatic pregnant and non-pregnant women, this underpins that TUG targets activities relevant to PGP. Our results provide new knowledge about factors influencing TUG time. Importantly, multivariable analyses suggest that pain intensity should be considered when interpreting TUG time in pregnant women with PGP.

Kinematic and spatiotemporal gait characteristics in pregnant women with pelvic girdle pain, asymptomatic pregnant and non-pregnant women.

BACKGROUND: Walking difficulties are common among pregnant women with pelvic girdle pain. This cross-sectional study investigated the influence of pelvic girdle pain, pregnancy and speed on spatiotemporal and trunk, pelvic and hip kinematics during gait in the 2nd trimester of pregnancy. METHODS: Three-dimensional gait analysis at self-selected speed was performed in 25 pregnant women with pelvic girdle pain, 24 asymptomatic pregnant and 24 non-pregnant women. Linear mixed models were used to investigate between-group differences in gait variables. Adjustment for gait speed was included in the analysis. Correlations between speed and fear of movement, disability and pain were examined using Spearman correlation coefficient (rs). FINDINGS: Pregnant women with pelvic girdle pain walked 18% slower (estimated marginal means (95% confidence intervals) 1.18 (1.22, 1.24) meter/s) compared to asymptomatic pregnant women (1.44 (1.38, 1.50) meter/s) (P < 0.001). Moreover, with longer double limb support (5%, P = 0.04), shorter contralateral step length (3%, P = 0.03) and more restricted pelvic and hip kinematics (0.001 ≤ P ≤ 0.01) adjusted for speed. Only stance, double limb support and thoracic rotation (0.001 ≤ P ≤ 0.04) differed between asymptomatic pregnant and non-pregnant women. Speed was negatively correlated with fear of movement (rs = -0.63, P = 0.01) and disability (rs = -0.46, P = 0.03) in the pelvic girdle pain group. INTERPRETATION: Gait is primarily influenced by pelvic girdle pain and less by pregnancy. Pregnant women with pelvic girdle pain walked slower and with a more rigid gait pattern compared to asymptomatic pregnant women, presumably related to altered load transfer. Our results may assist clinical evaluation of pelvic girdle pain, as well as direct future research.

The effects of task complexity on brake response time before and after primary right total knee arthroplasty.

OBJECTIVE: To study the effects of an increase in task complexity on brake response time (BRT) in patients undergoing total knee arthroplasty (TKA). DESIGN: A prospective repeated-measures design was used. The measurements took place 1 day before and 10 and 30 days after surgery. SETTING: Clinic. PARTICIPANTS: The data of patients (N=21) who were admitted for primary total arthroplasty of the right knee were pooled for analysis. INTERVENTIONS: On each measurement day patients performed 5 practice and 10 test trials for 2 tasks (1 simple, 1 complex) in a car simulator. Task complexity was increased by adding a second movement to the first task performed. MAIN OUTCOME MEASURES: BRT, reaction time (RT), and movement time were assessed. RESULTS: An increase in task complexity increased BRT, RT, and movement time at all measurement times. Right TKA increased BRT by increasing movement time. Thirty days after surgery BRT was no longer increased compared with preoperative values in both tasks. CONCLUSIONS: Task complexity consistently increased BRT and its components. The effects of task complexity remained constant throughout the 3 measurements. After right TKA, we suggest patients should be advised to wait 30 days after surgery before resuming driving.

Does the brake response time of the right leg change after left total knee arthroplasty? A prospective study.

Patients undergoing total knee arthroplasty often ask when they can safely resume car driving. There is little evidence available on which physicians can rely when advising patients on this issue. In a prospective study we assessed the brake response time of 24 patients admitted to the clinic for left total knee arthroplasty preoperatively and then 10 days after surgery. On each measurement day the patients performed two tasks, a simple and a complex brake response time task in a car simulator. Ten days after left TKA the brake response time for the simple task had decreased by 3.6% (p=0.24), the reaction time by 3.1% (p=0.34) and the movement time by 6.6% (p=0.07). However, the performance improvement was not statistically significant. Task complexity increased brake response time at both time points. A 5.8% increase was significant (p=0.01) at 10 days after surgery. Based on our results, we suggest that patients who have undergone left total knee arthroplasty may resume car driving 10 days after surgery as long as they drive a car with automatic transmission.

Hand reach star excursion balance test: An alternative test for dynamic postural control and functional mobility.

Tests of dynamic postural control eliciting full-body three-dimensional joint movements in a systematic manner are scarce. The well-established star excursion balance test (SEBT) elicits primarily three-dimensional lower extremity joint movements with minimal trunk and no upper extremity joint movements. In response to these shortcomings we created the hand reach star excursion balance test (HSEBT) based on the SEBT reach directions. The aims of the current study were to 1) compare HSEBT and SEBT measurements, 2) compare joint movements elicited by the HSEBT to both SEBT joint movements and normative range of motion values published in the literature. Ten SEBT and HSEBT reaches for each foot were obtained while capturing full-body kinematics in twenty recreationally active healthy male subjects. HSEBT and SEBT areas and composite scores (sum of reaches) for total, anterior and posterior subsections and individual reaches were correlated. Total reach score comparisons showed fair to moderate correlations (r = .393 to .606), while anterior and posterior subsections comparisons had fair to good correlations (r = .269 to .823). Individual reach comparisons had no to good correlations (r = -.182 to .822) where lateral and posterior reaches demonstrated the lowest correlations (r = -.182 to .510). The HSEBT elicited more and significantly greater joint movements than the SEBT, except for hip external rotation, knee extension and plantarflexion. Comparisons to normative range of motion values showed that 3 of 18 for the SEBT and 8 of 22 joint movements for the HSEBT were within normative values. The findings suggest that the HSEBT can be used for the assessment of dynamic postural control and is particularly suitable for examining full-body functional mobility.