For lower extremity injury prevention, it is crucial to decrease external loads to the joints in sport-specific situations. The purpose of this study was to examine how landing kinetics and psychological factors (i.e., motivation) change during a four-week laboratory training program. Ten talented soccer girls practiced three sport-specific tasks and received expert video instruction. Increased fun and competence in week 3 compared to week 1 was observed. No significant changes of effort and joint load (a discrete number to describe combined external frontal and transverse plane knee and ankle moments) were found. Results are promising and innovative as this is the first study testing the entire OPTIMAL model including retention and linking biomechanics with perceived motivation. More research is planned on additional instructions and feedback that may enhance the motor learning curve.

Gait, the pattern or style in which locomotion is undertaken, has kinematic characteristics that may occur in varying proportions of a population and therefore have discriminatory potential. Forensic gait analysis is the analysis, comparison and evaluation of features of gait to assist the investigation of crime. While there have been recent developments in automated gait recognition systems, gait analysis presented in criminal court to assist in identification currently relies on observational analysis by expert witnesses. Observational gait analysis has been the focus of considerable research, and it has been shown that the adoption of a systematic approach to both the observation and recording of features of gait improves the reliability of the analysis. The Sheffield Features of Gait Tool was developed by forensic gait analysis practitioners based on their casework and trial experience, and consists of more than a hundred features of gait and variances. This paper reports the findings of a study undertaken to assess the repeatability and reproducibility of the Sheffield Features of Gait Tool. Fourteen participants, with experience in observational gait analysis, viewed footage of computer generated avatars walking, and completed the features of gait tool on multiple occasions. The repeatability scores varied between participants from a highest score of 42.59 out of a maximum possible score of 45 (94.65%), to a lowest score of 30.76 (68.35%), with a mean score of 35.79 (79.54%) and a standard deviation of 3.59 (7.98%). The reproducibility scores for the assessment of each avatar varied from a highest score of 137.73 out of the best possible score of 180 (76.52%), to a lowest score of 127.21 (70.67%), with a mean score of 132.21 (73.45) and a standard deviation of 3.82 (2.12%). The results demonstrated that the use of the Sheffield Features of Gait Tool by experienced analysists resulted in what could be considered to be good levels of both repeatability and reproducibility. Some variation was shown to occur both between the results produced by different analysts, and between those produced from the analysis of different avatars. An understanding of the probative value of gait analysis evidence is an important facet of its submission as evidence, and the design and testing of standardized methods of analysis and comparison are an essential element of developing that understanding. This study is the first to test a purpose designed features of gait tool for use in forensic gait analysis.

Plantar fasciitis is a frequently occurring overuse injury of the foot. Shoes with a stiff rocker profile are a commonly prescribed treatment modality used to alleviate complaints associated with plantar fasciitis. In rocker shoes the apex position was moved proximally as compared to normal shoes, limiting the progression of the ground reaction forces (GRF) and peak plantarflexion moments during gait. A stiff sole minimizes dorsiflexion of the toes. The aim of this study was to investigate whether the biomechanical effects of rocker shoes lead to minimization of plantar aponeurosis (PA) strain during gait in patients with plantar fasciitis and in healthy young adults. 8 patients with plantar fasciitis (1 male, 7 females; mean age 55.0 ± 8.4 years) and 8 healthy young adults (8 females; mean age 24.1 ± 1.6 years) participated in the study. Each participant walked for 1 minute on an instrumented treadmill while wearing consecutively in random order shoes with a normal apex position (61.2 ± 2.8% apex) with flexible insole (FN), normal apex position with stiff insole (SN), proximal apex position (56.1 ± 2.6% apex) with flexible insole (FR) and proximal apex position with stiff insole (SR). Marker position data of the foot and lower leg and GRF were recorded. An OpenSim foot model was used to compute the change in PA length based on changes in foot segment positions during gait. The changes in PA length due to increases in Achilles tendon forces were computed based on previous data of a cadaver study. PA strain computed from both methods was not statistically different between shoe conditions. Peak Achilles tendon force, peak first metatarsophalangeal (MTP1) joint angle and peak plantarflexion moment were significantly lower when walking with the rocker shoe with a proximal apex position and a stiff insole for all subjects (p<.05). Changes in Achilles tendon forces during gait accounted for 65 ± 2% of the total PA strain. Rocker shoes with a stiff insole reduce peak dorsiflexion angles of the toes and plantar flexion moments, but not PA strain because the effects of a proximal apex position and stiff insole do not occur at the same time, but independently affect PA strain at 80–90% and 90–100% of the stance phase. Rocker shoes with an apex position of ~56% are insufficient to significantly reduce peak PA strain values in patients with plantar fasciitis and healthy young adults.

As humans, we express what we think and feel by facial movements, often without even realizing it. In the (e)motion installation, the goal was to create awareness of even the subtlest movements of the face, and to facilitate interaction purely based on facial expressions. Facial movements were tracked by custom software and translated into motion vectors, which were in turn visualized and coupled with sounds. Participants could interact within the installation by responding to each other's facial movements. (e)motion was inspired by embodied cognition and scientific studies on emotion and action. The installation was the result of an interdisciplinary collaboration between art, movement science and cognitive neuroscience.

It is unknown how movement patterns that are learned carry over to the field. The objective was to determine whether training during a jump-landing task would transfer to lower extremity kinematics and kinetics during sidestep cutting.

Background: Retention of movement technique is crucial in anterior cruciate ligament (ACL) injury prevention programs. It is unknown if specific instructions or video instructions result in changes in kinematic and kinetic measures during a relatively short training session, and in a retention test one week later. Hypothesis/Purpose: The purpose was to determine the effects of verbal external focus (EF), verbal internal focus (IF) and video instructions (VI) on landing technique (i.e. kinematics and kinetics) during training and retention. Study Design: Randomized Controlled Trial. Methods: This study compared verbal EF, verbal IF, VI and CTRL group. Forty healthy athletes were assigned to the IF (n=10), EF (n=10), VI (n=10) or CTRL group (n=10). A jump-landing task was performed as a baseline, followed by two training blocks (TR1 and TR2) and a post test. Group specific instructions were offered in TR1 and TR2. In addition, subjects in the IF, EF and VI groups were free to ask for feedback after every jump in TR1 and TR2. One week later, a retention test was conducted without specific instructions or feedback. Kinematics and kinetics were captured using an 8-camera motion analysis system. Results: Males and females in the EF and VI instruction group showed beneficial results during and after the training session, in terms of improved landing technique. Retention was achieved after only a short training session. Conclusion: ACL injury prevention programs should include EF and/or VI instructions to improve kinematics and kinetics and achieve retention. Level of Evidence: 3b.

Adding external focus of attention (EF, focus on the movement effect) may optimize current anterior cruciate ligament (ACL) injury prevention programmes. The purpose of the current study was to investigate the effects of an EF, by a visual stimulus and an internal focus, by a verbal stimulus during unexpected sidestep cutting in female and male athletes and how these effects remained over time.

Background It is unknown if learned motor skills as practiced in ACL injury prevention training carry over to other tasks. Objective Determine if training of a jump-landing task results in transfer of improvement in lower extremity biomechanics during sidestep cutting. Design Randomized controlled trial. Setting Controlled laboratory setting, recreational athletes. Participants Twenty male and twenty female healthy team ball sport athletes were randomly assigned to a verbal internal focus (IF, n=10), verbal external focus (EF, n=10), video (VI, n=10) or control group (CTRL, n=10). Interventions A jump-landing task was performed at baseline followed by training blocks (TR1 and TR2), an immediate post-test and an one-week retention test. Subjects in the IF, EF and VI groups received group specific instructions in TR1 and TR2. Transfer was determined after one week with a 45° unanticipated sidestep cutting task. Main Outcome Measurements Hip and knee flexion range of motion (ROM). Results During sidestep cutting, males in the VI (5.1°±1.0) and CTRL (5.1°±1.0) group showed greater hip flexion ROM compared to the IF (3.7°±0.0) and EF (3.0°±1.5) groups (p<0.05). For females, the VI group (7.0°±1.0) showed greater hip flexion ROM compared to the IF (0.6°±0.0), EF (1.3°±0.7) and CTRL (2.7°±0.0) groups (p<0.05). The EF (males −15.8°±3.9, females −11.0°±3.0) and VI (males −15.1°±2.6, females −16.7°±1.8) groups showed greater knee flexion ROM compared to the IF (males −6.6°±3.9, females −6.0°±1.3) group (p<0.05). Conclusions Athletes who received VI instructions demonstrated transfer of improved movement technique from jump-landing to sidestep cutting. Adding visual instruction to ACL injury prevention programs seems promising for transfer to sport specific situations.

Background In handball an anterior cruciate ligament injury often occurs during a jump shot landing. Video feedback is effective to improve landing although little is known about its influence in sport-specific movements. Objective Test effectiveness of video overlay feedback on landing technique. Design Randomized controlled trial. Setting Controlled laboratory with elite athletes. Participants Sixteen female handball players were randomly assigned to a Control (CG) or Video (VG) Group. Interventions Both groups performed jump shots in pre-test (5 trials), two training sessions (TR1 & TR2, 2x10 trials) and post-test (5 trials). In TR1 and TR2, the VG received self-controlled video feedback of an expert model with an overlay of their own jump shots. Main Outcome Measurements Knee and hip flexion angles (initial contact (IC), maximum (MAX) and range of motion (ROM)). Landing Error Scoring System (LESS) score. Shot accuracy, jump height and distance to assess performance. Results From pre- to post-test, knee (pre-test IC: −12.4°±3.9, post-test IC: −17.3°±2.4, pre-test MAX: −70.4°±2.8, post-test MAX: −99.6°±11.3, pre-test ROM: −58.1°±5.3, post-test ROM: −82.3°±10.5) and hip (pre-test IC: 29.7°±4.4, post-test IC: 38.7°±6.4, pre-test MAX: 58.9°±11.4, post-test MAX: 97.8°±17.6, pre-test ROM: 31.6°±12.5, post-test ROM: 63.9°±11.7) flexion improved in the VG (p<0.05). The VG reduced their LESS score (pre-test 8.1, post-test 4.0; p<0.05). CG did not show significant changes, resulting in group*time interaction effects for mentioned variables (p<0.05). No differences were found in shot accuracy and jump height, whilst jump distance increased at post-test in the VG. Conclusions Overlay visual feedback is effective to improve landing technique during a jump shot whilst maintaining performance. For enhancing injury prevention, it is imperative to determine long-term effects and transfer to training and game situations.

A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a person acting on a prosthetic foot during roll-over was emulated by means of an inverted pendulum-like apparatus. Parameters measured were the effective radius of curvature, the forward travel of the center of pressure, and the instantaneous radius of curvature of the prosthetic feet. Finally, we discuss how these parameters relate to amputee gait. & 2009 Elsevier Ltd. All rights reserved.

INTRODUCTION:To achieve personal goals in exercise task completion, exercisers have to regulate, distribute, and manage their effort. In endurance sports, it has become very commonplace for athletes to consult task-related feedback on external devices to do so. The aim of the present study was to explore the importance of the presence of this information by examining the influence of the absence of commonly available task-related feedback on effort distribution and performance in experienced endurance athletes.METHODS:A 20-km cycling time trial was performed. Twenty Participants from a homogenous cyclist population were appointed to a group that did not receive any feedback (NoF), or a group that could consult task-related feedback (i.e., speed, heart rate, power output, cadence, elapsed time, and elapsed distance) continuously during their trial (FF).RESULTS:The distribution of power output (PO) differed between groups. Most evident is the spurt at the end of the trial of FF, which was not incorporated by NoF. Nevertheless, no between-group differences were found in performance time (FF: 28.86 ± 3.68 vs. NoF: 30.95 ± 2.77 min) and mean PO controlled by body mass (FF: 3.61 ± 0.60 vs. NoF: 3.43 ± 0.38 W/kg). Also, no differences in rating of perceived exertion scores were found.CONCLUSION:The current study provides a first indication that prior knowledge of task demands together with reliance on bodily and environmental information can be sufficient for experienced athletes to come to comparable time trial performances. This questions the necessity of the presence of in-race instantaneous task-related feedback via external devices for maximizing performance. Moreover, it seems that different pacing strategies emerge depending on sources of information available to experienced athletes.

With the loss of a lower limb, amputees lack the active muscle empowered control of the ankle that is important for balance control. We examined single-leg stance on prosthesis vs. sound limb balancing on narrow ridges in transtibial amputees. When balancing on the prosthetic limb, the lateral displacement of the center of pressure was reduced and was compensated by an increase in counter-rotation. We show that single-leg stance on a prosthetic limb can be compared to balancing on a narrow ridge. Standing on a prosthetic limb involves the same balance mechanisms as balancing on narrow ridges of 40-mm to 20-mm width. Yet, the ability to balance on a narrow ridge with the sound limb was only a weak predictor for an amputee's ability to stand on the prosthetic limb. Balancing in single-leg stance on a prosthetic limb is not a common activity. The ability to compensate with the sound limb may therefore be functionally more important than the ability to stay in dynamic balance on the prosthetic limb.

The aim of this study was to examine the level and recovery of motor imagery ability (MIA) in the first year after stroke and whether the recovery of MIA is related to that of arm/hand function. Twenty-three patients with diminished arm/hand function were included. The accuracy score on the hand laterality judgment task was used to assess MIA and the Fugl-Meyer Assessment was used to evaluate the recovery of arm/hand function. The patients were assessed 3, 6, 16, 26, and 52 weeks after stroke. In the first year after stroke, the percentage of patients with moderate to good MIA improved from 78% after 3 weeks to 94% after 1 year. The recovery of MIA took place in the first 6 weeks after stroke. No correlation was found between the recovery of MIA and arm/hand function, despite the fact that the greatest improvement in both occurred in the first 6 weeks.

BACKGROUND:Children with developmental coordination disorder (DCD) face evident motor difficulties in daily functioning. Little is known, however, about their difficulties in specific activities of daily living (ADL).OBJECTIVE:The purposes of this study were: (1) to investigate differences between children with DCD and their peers with typical development for ADL performance, learning, and participation, and (2) to explore the predictive values of these aspects.DESIGN:This was a cross-sectional study.METHODS:In both a clinical sample of children diagnosed with DCD (n=25 [21 male, 4 female], age range=5-8 years) and a group of peers with typical development (25 matched controls), the children's parents completed the DCDDaily-Q. Differences in scores between the groups were investigated using t tests for performance and participation and Pearson chi-square analysis for learning. Multiple regression analyses were performed to explore the predictive values of performance, learning, and participation.RESULTS:Compared with their peers, children with DCD showed poor performance of ADL and less frequent participation in some ADL. Children with DCD demonstrated heterogeneous patterns of performance (poor in 10%-80% of the items) and learning (delayed in 0%-100% of the items). In the DCD group, delays in learning of ADL were a predictor for poor performance of ADL, and poor performance of ADL was a predictor for less frequent participation in ADL compared with the control group.LIMITATIONS:A limited number of children with DCD were addressed in this study.CONCLUSIONS:This study highlights the impact of DCD on children's daily lives and the need for tailored intervention.

External focus instructions have been shown to result in superior motor performance compared to internal focus instructions. Using an EF may help to optimize current anterior cruciate ligament (ACL) injury prevention programs. The purpose of the current study was to investigate the effects of instructions on landing technique and performance by comparing an external focus (EF), internal focus (IF), video (VI) and control (CTRL) group. Subjects (age 22.50±1.62years, height 179.70±10.43cm, mass 73.98±12.68kg) were randomly assigned to IF (n=10), EF (n=10), VI (n=10) or CTRL group (n=10). Landing was assessed from a drop vertical jump (DVJ) in five sessions: pretest, two training blocks (TR1 and TR2) and directly after the training sessions (post test) and retention test 1week later. Group specific instructions were offered in TR1 and TR2. Landing technique was assessed with the Landing Error Scoring System (LESS) and jump height was taken as performance measure. The results show that males in the VI group and females both in the VI and EF groups significantly improved jump-landing technique. Retention was achieved and jump height was maintained for males in the VI group and females both in the VI and EF groups. It is therefore concluded that EF and VI instructions have great potential in ACL injury prevention.

External of focus of attention has been shown to result in superior motor performance compared to an internal focus of attention. Adding external focus of attention may optimize current anterior cruciate ligament (ACL) injury prevention programs. Objective: To determine the effect of internal (IF) and external focus (EF) and video instruction (VI) on drop vertical jump (DVJ) landing strategies assessed with landing error scoring system (LESS). Design; Descriptive cohort study. Setting; Controlled laboratory setting. Patients and Other Participants; Forty recreational athletes performed DVJ’s in five sessions: a pretest (baseline measurements), two training blocks (TR1 and TR2), a posttest directly after the training sessions and a retention test one week later. Subjects were randomly assigned to one of the four groups; IF (n=10, ), EF (n=10, ), VI (n=10, ) or the CTRL group (n=10, ), with 5 females and 5 males in each group. 22.60±1.35 years, 1.80±0.14 m, 72.40±10.38 kg Interventions: After a general instruction before pretest, group specific instruction was offered before TR1 and TR2 started and after every 5 trials in TR1 and TR2. The IF group received an instruction regarding attention to the body, the EF group received an instruction directed to the movement effect and the VI group viewed an expert video. Subjects in the IF, EF and VI groups were free to ask for feedback on their real time LESS during TR1 and TR2. Subjects were only aware that a lower LESS score implied a better landing strategy. A 4x5x2 repeated measures ANOVA was conducted to determine differences between groups (IF, EF, VI and CTRL), time (pretest, TR1, TR2, posttest and retention test) and gender (female and male), followed by post hoc comparisons (Bonferroni) with alpha level set at α≤0.05 a priori. Main Outcome Measures: Mean total LESS scores. Results: Males in the VI group had significant lower LESS scores in the post- (1.92±0.27) and retention test (1.72±0.30) compared to the pretest (2.72±0.83).

Anterior cruciate ligament (ACL) injury prevention programs have been successful in the short term. Motor learning strategies with an internal focus (IF) to body movements have traditionally been utilized, but may be less suitable than an external focus (EF) for the acquisition and control of complex motor skills required for sport. To investigate the available literature and provide an overview of the effect of IF and EF instructions on jump landing technique. Systematic searches were conducted in PubMed (1966 to May 2014), CINAHL (1981 to May 2014) and PsycInfo (1989 to May 2014). A priori defined inclusion criteria were: (i) full text; (ii) published in English, German or Dutch; (iii) healthy adult subjects (mean age ≥18 years); (iv) jump and landing performance tested and (v) study used comparison between an EF and IF. Performance (jump height and distance) and technique (kinematics and kinetics) were the primary outcome variables of interest. Nine papers were included. Significant better motor performance and movement technique was found with an EF compared to an IF. Considering the beneficial results in the included studies when utilizing an EF, it is suggested to implement these strategies into ACL injury prevention programs.

OBJECTIVES:The purpose of this study was to determine the effect of an internal and external attentional focus on single leg hop jump distance and knee kinematics in patients after ACL reconstruction (ACLR).DESIGN:Experimental.SETTING:Outpatient physical therapy facility.PARTICIPANTS:Sixteen patients after ACLR.MAIN OUTCOME MEASURES:Patients received either an instruction with an internal focus or an external focus before performing a single leg hop jump. The jump distance, knee valgus angle at initial contact, peak knee valgus angle, knee flexion angle at initial contact, peak knee flexion angle, total ROM and time to peak angles for the injured and non-injured legs were recorded. A repeated measures MANOVA was used to determine significance between the experimental conditions with the primary outcome measures as dependent variables.RESULTS:The external focus group had significant larger knee flexion angles at initial contact, peak knee flexion, total ROM and time to peak knee flexion for the injured legs.CONCLUSIONS:This study demonstrates the applicability of using an external focus during rehabilitation of patients after ACLR to enhance safer movement patterns compared to an internal focus of attention and subsequently may help to reduce second ACL injury risk.