title: Effects of task-specific augmented feedback on deficit modification during performance of the tuck-jump exercise. Motor learning strategies in basketball players and its implications for ACL injury prevention: a randomized controlled trial Feedback-Induced Variability and the Learning of Generalized Motor Programs. Augmented feedback reduces jump landing forces. The effect of videotape augmented feedback on drop jump landing strategy: Implications for anterior cruciate ligament and patellofemoral joint injury prevention. Effect of attention focus on acquisition and retention of postural control following ankle sprain. Effects of instruction in jumping technique and experience jumping on ground reaction forces. Effect of focus of attention on transfer of a postural control task following an ankle sprain. Augmented Feedback Supports Skill Transfer and Reduces High-Risk Injury Landing Mechanics Attentional focus of feedback for improving performance of reach-to-grasp after stroke: a randomised crossover study.
abstract: CONTEXT Anterior cruciate ligament ( ACL ) injuries are prevalent in female athletes . Specific factors have possible links to increasing a female athlete 's chances of suffering an ACL injury . However , it is unclear if augmented feedback may be able to decrease possible risk factors . OBJECTIVE To compare the effects of task-specific feedback on a repeated tuck-jump maneuver . DESIGN Double-blind r and omized controlled trial . SETTING Sports-medicine biodynamics center . PATIENTS 37 female subjects ( 14.7 ± 1.5 y , 160.9 ± 6.8 cm , 54.5 ± 7.2 kg ) . INTERVENTION All athletes received st and ard off-season training consisting of strength training , plyometrics , and conditioning . They were also videotaped during each session while running on a treadmill at a st and ardized speed ( 8 miles/h ) and while performing a repeated tuck-jump maneuver for 10 s. The augmented feedback group ( AF ) received feedback on deficiencies present in a 10-s tuck jump , while the control group ( CTRL ) received feedback on 10-s treadmill running . MAIN OUTCOME MEASURES Outcome measurements of tuck-jump deficits were scored by a blinded rater to determine the effects of group ( CTRL vs AF ) and time ( pre- vs posttesting ) on changes in measured deficits . RESULTS A significant interaction of time by group was noted with the task-specific feedback training ( P = .03 ) . The AF group reduced deficits measured during the tuck-jump assessment by 23.6 % , while the CTRL training reduced deficits by 10.6 % . CONCLUSIONS The results of the current study indicate that task-specific feedback is effective for reducing biomechanical risk factors associated with ACL injury . The data also indicate that specific components of the tuck-jump assessment are potentially more modifiable than others Purpose 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 . Methods Ninety experienced basketball athletes performed sidestep cutting manoeuvres in three sessions ( S1 , S2 and S3 ) . In this r and omized controlled trial , athletes were allocated to three groups : visual ( VIS ) , verbal ( VER ) and control ( CTRL )  . Kinematics and kinetics were collected at the time of peak knee frontal plane moment . Results Males in the VIS group showed a larger vertical ground reaction force ( S1 : 25.4 ± 3.1 N/kg , S2 : 25.8 ± 2.9 N/kg , S3 : 25.2 ± 3.2 N/kg ) and knee flexion moments ( S1 : −3.8 ± 0.9 Nm/kg , S2 : −4.0 ± 1.2 Nm/kg , S3 : −3.9 ± 1.3 Nm/kg ) compared to the males in the VER and CTRL groups and to the females in the VIS group ( p < 0.05 ) . Additionally , the males in the VIS group reduced knee valgus moment and the females in the VER group reduced knee varus moment over time ( n.s . ) . Conclusion Male subjects clearly benefit from visual feedback . Females may need different feedback modes to learn a correct movement pattern . Sex-specific learning preferences may have to be acknowledged in day by day practice . Adding video instruction or feedback to regular training regimens when teaching athletes safe movement patterns and providing individual feedback might target suboptimal long-term results and optimize ACL injury prevention programmes . Level of evidence As compared with providing extrinsic feedback on each of a set of practice trials , reducing the feedback frequency in various ways facilitates long-term retention . One explanation is that frequent feedback operates proactively on the subsequent trial , inducing excessive variability that de grade s learning . We tested this view by giving or not giving feedback " reminders , " where the postresponse feedback was given again just before the next attempt at a task . The reminder manipulation was examined in both  blocked and r and omized practice sequences during the learning of three limb-patterning tasks .  Reminder feedback increased response variability during practice in both r and om and blocked practice . As measured in retention tests , though , feedback reminders de grade d learning in r and om practice , but not in blocked practice . This implies that the frequently found learning advantages of r and om , as compared with blocked , practice might be due to feedback 's facilitation of retrieval operations in blocked practice ( as well as in r and om practice with feedback reminders ) ; such overfacilitation of retrieval operations has been shown to de grade learning . Additional analyses revealed that r and om , as compared with blocked , practice enhanced the learning of the fundamental pattern of action ( generalized motor program ) but had little effect on the ability to scale the pattern in amplitude or time ( parameterization ) STUDY DESIGN R and omized , experimental design using a 1-way ANCOVA to determine the influence of various forms of feedback on jump l and ing forces . OBJECTIVE To investigate the effects of augmented feedback versus sensory feedback on the reduction of jump l and ing forces . BACKGROUND Several investigators have reported an increased risk of lower extremity injury associated with l and ing from a jump . METHODS AND MEASURES Nonimpaired college students ( N=63 ) were r and omly assigned to 1 of 4 feedback groups . Subjects were instructed to perform maximal vertical jumps onto a force plate for 3 testing sessions ( baseline , 2-minute post-test , and 1-week post-test ) . Three feedback groups ( augmented , sensory , and control I ) were tested during all 3 testing sessions , while a fourth feedback group ( control II ) was evaluated at only 2 sessions ( baseline and 1-week post-test ) . Subjects in the augmented feedback condition were provided information via video and verbal analysis of how to l and softer . Subjects in the sensory feedback condition were asked to use the experience of their baseline jumps to document how they could l and softer . Subjects in each of the control groups were not provided any extraneous feedback . Peak vertical ground reaction force data were collected for analysis . RESULTS The subjects in the augmented feedback group significantly reduced their peak vertical ground reaction force in both post-test conditions ( 2-minute post-test reduction , 0.85+/-0.62 ; 1-week post-test reduction , 0.74+/-0.58 ) as compared to the sensory , control I , and control II feedback groups . CONCLUSIONS High impact l and ing forces may be reduced by the implementation of augmented feedback information instructing individuals about how to l and properly . The reduction of jump l and ing forces with the use of augmented feedback may prove beneficial in the creation of instructional l and ing programs BACKGROUND Modification of high-risk movement strategies such as dynamic knee valgus is key to the reduction of anterior cruciate ligament ( ACL ) and patellofemoral joint ( PFJ ) injuries . Augmented feedback , which includes video and verbal feedback , could offer a quick , simple and effective alternative to training programs for altering high-risk movement patterns . It is not clear whether feedback can reduce dynamic knee valgus measured using frontal plane projection angle ( FPPA ) . METHODS Vertical ground reaction force ( vGRF ) , two-dimensional FPPA of the knee , contact time and jump height of 20 recreationally active university students were measured during a drop jump task pre- and post- an augmented feedback intervention .  A control group of eight recreationally active university students were also studied at baseline and repeat test . RESULTS There was a significant reduction in vGRF ( p=0.033 ) , FPPA ( p<0.001 ) and jump height ( p<0.001 ) and an increase in contact time ( p<0.001 ) post feedback in the intervention group . No changes were evident in the control group . CONCLUSION Augmented feedback leads to significant decreases in vGRF , FPPA and contact time which may help to reduce ACL and PFJ injury risk . However , these changes may result in decreased performance . CLINICAL RELEVANCE Augmented feedback reduces dynamic knee valgus , as measured via FPPA , and forces experienced during the drop jump task and therefore could be used as a tool for helping decrease ACL and PFJ injury risk prior to , or as part of , the implementation of injury prevention training programs OBJECTIVE To examine the effect of attentional focus instructions and dynamic balance training on ankle sprain recovery .  DESIGN R and omized controlled trial . SETTING Outpatient physical therapy department . PARTICIPANTS Forty volunteers ( age range , 19 - 33y ) referred to treatment within 4 months after sustaining a grade 1 or 2 ankle sprain with no concurrent impairments . Participants were r and omly allocated to 1 of 2 groups differing in training instructions . INTERVENTION Postural control training consisted of ten 20-second trials , performed on 3 consecutive days , at 2 stability levels of the Biodex Stability System ( BSS ) . Training instructions directed the participants to either an internal or an external focus of attention . Assessment s were conducted on the BSS pre- and post-training , and 48 hours after the last session ( retention test ) . MAIN OUTCOME MEASURES Overall stability as indicated by variance in platform displacement in all directions ; anteroposterior ( AP ) variance of platform displacement ; and mediolateral variance of platform displacement . RESULTS Increases in overall and AP stability were observed immediately following training in both groups and were maintained at the retention test . Interaction effect indicates greater improvement in the external-focus group . CONCLUSIONS Our results suggest that external focus of attention is advantageous for the learning of a postural control task following an ankle injury STUDY DESIGN R and omized , controlled trial . OBJECTIVE To determine the roles that augmented feedback from instruction in jumping technique and sensory feedback from experience jumping play in assisting individuals to l and softly from a jump . BACKGROUND Jumping and l and ing activities play a major role in many sports and daily activities . Feedback may assist individuals in decreasing l and ing forces and thus reduce the chances of sustaining an injury . METHODS AND MEASURES Nonimpaired subjects ( n = 91 ) were r and omly assigned to either an augmented or sensory feedback condition . All subjects were asked to jump from a box 300 mm in height and l and as softly as possible on a force plate . Pre-intervention ground reaction forces ( GRF ) were recorded . Subjects in the augmented feedback condition were then given instructions to focus on hip and knee joint motion as well as a forefoot l and ing technique for their next jump . Subjects in the sensory feedback condition were asked to use the experience of their first jump to l and softly for their next jump . Post-intervention GRFs were recorded and all GRFs were expressed as a multiple of body weight . RESULTS Those in the augmented condition significantly reduced their GRF scores from pre-(mean = 4.53 + /- 1.51 ) to post-(mean = 3.57 + /- 1.10 ) jump , whereas those in the sensory condition did not ( mean pre GRF = 4.51 + /- 1.77 ; mean post GRF = 4.33 + /- 1.54 ) . CONCLUSIONS High ground reaction forces may be a precipitating factor associated with an injury , where the site of tissue damage would benefit from decreased forces . These findings support the use of instructions related to joint motion to reduce l and ing forces STUDY DESIGN R and omized clinical trial . OBJECTIVE To examine the effect of attentional focus instructions during training on the transfer of a learned balance capability to a more challenging condition among subjects with ankle ligament injury . BACKGROUND Current evidence suggests that instructions inducing an external focus of attention may be more effective at promoting learning than instructions inducing an internal focus of attention . The effect of attentional direction on transfer has not been tested in population s following a disease or injury , such as lateral ankle sprain , in which postural control is impaired . METHODS AND MEASURES Participants were 36 male volunteers ( mean age , 20.9 years ; range , 19 - 33 years ) who were referred to physical therapy following a grade 1 or 2 ankle sprain . The patients were r and omly allocated to 1 of 2 groups , which were instructed to focus attention either internally or externally during postural control training . Three training sessions were conducted on consecutive days and consisted of ten 20-second trials at 2 stability levels , using the Biodex Stability System . Postural control at an untrained , less stable level was assessed before the initial training session and 48 hours following the last session using the Biodex Stability System . Three measures of stability were used : ( 1 ) overall stability , as indicated by the variance in platform displacement in all directions , ( 2 ) anterior/posterior variance of platform displacement , and ( 3 ) medial/lateral variance of platform displacement . RESULTS Participants utilizing an external focus of attention improved significantly over the study period in all 3 stability indices , while those utilizing internal focus of attention did not improve significantly . CONCLUSIONS Our results suggest that an external focus of attention is advantageous for the transfer of learning of a postural control task following an ankle injury . Furthermore , they indicate that using an external focus of attention when training under moderately unstable conditions can significantly improve postural control under less stable conditions Background : There is a current need to produce a simple , yet effective method for screening and targeting possible deficiencies related to increased anterior cruciate ligament ( ACL ) injury risk . Hypothesis : Frontal plane knee angle ( FPKA ) during a drop vertical jump will decrease upon implementing augmented feedback into a st and ardized sport training program . Study Design : Controlled laboratory study . Methods : Thirty-seven female participants ( mean ± SD : age , 14.7 ± 1.5 years ; height , 160.9 ± 6.8 cm ; weight , 54.5 ± 7.2 kg ) were trained over 8 weeks . During each session , each participant received st and ardized training consisting of strength training , plyometrics , and conditioning . They were also videotaped running on a treadmill at a st and ardized speed and performing a repeated tuck jump for 10 seconds . Study participants were r and omized into 2 groups and received augmented feedback on either their jumping ( AF ) or sprinting ( CTRL ) form . Average ( mean of 3 trials ) and most extreme ( trial with greatest knee abduction ) FPKA were calculated from 2-dimensional video captured during performance of the drop vertical jump . Results : After testing , a main effect of time was noted , with the AF group reducing their FPKA average by 37.9 % over the 3 trials while the CTRL group demonstrated a 26.7 % reduction average across the 3 trials ( P < .05 ) . Conversely , in the most extreme drop vertical jump trial , a significant time-by-group interaction was noted ( P < .05 ) . The AF group reduced their most extreme FPKA by 6.9 ° ( pretest , 18.4 ° ± 12.3 ° ; posttest , 11.4 ° ± 10.1 ° ) on their right leg and 6.5 ° ( pretest , 16.3 ° ± 14.5 ° ; posttest , 9.8 ° ± 10.7 ° ) on their left leg , which represented a 37.7 % and 40.1 % reduction in FPKA , respectively . In the CTRL group , no similar changes were noted in the right ( pretest , 16.9 ° ± 14.3 ° ; posttest , 14.0 ° ± 12.3 ° ) or left leg ( pretest , 9.8 ° ± 11.1 ° ; posttest , 7.2 ° ± 9.2 ° ) after training . Conclusion : Providing athletes with augmented feedback on deficits identified by the tuck jump assessment has a positive effect on their biomechanics during a different drop vertical jump task that is related to increased ACL injury risk . The ability of the augmented feedback to support the transfer of skills and injury risk factor reductions across different tasks provides exciting new evidence related to how neuromuscular training may ultimately cross over into retained biomechanics that reduce ACL injuries during sport . Clinical Relevance : The tuck jump assessment ’s ease of use makes it a timely and economically favorable method to support ACL prevention strategies in young girls OBJECTIVE To investigate whether feedback inducing an external focus ( EF ) of attention ( about movement effects ) was more effective for retraining reach-to-grasp after stroke compared with feedback inducing an internal focus ( IF ) of attention ( about body movement ) . It was predicted that inducing an EF of attention would be more beneficial to motor performance . DESIGN Crossover trial where participants were assigned at r and om to two feedback order groups : IF followed by EF or EF followed by IF . SETTING Research laboratory . PARTICIPANTS Forty-two people with upper limb impairment after stroke . INTERVENTION Participants performed three reaching tasks : ( A ) reaching to grasp a jar ; ( B ) placing a jar forwards on to a table ; and ( C ) placing a jar on to a shelf . Ninety-six reaches were performed in total over one training session . MAIN OUTCOME MEASURES Kinematic measures were collected using motion analysis . Primary outcome measures were movement duration , peak velocity of the wrist , size of peak aperture and peak elbow extension . RESULTS Feedback inducing an EF of attention produced shorter movement duration s { first feedback order group : IF mean 2.53 seconds [ st and ard deviation ( SD ) 1.85 ] ; EF mean 2.12 seconds ( SD 1.63 ) , mean difference 0.41 seconds ; 95 % confidence interval -0.68 to 1.5 ; P=0.008 } , an increased percentage time to peak deceleration ( P=0.01 ) when performing Task B , and an increased percentage time to peak velocity ( P=0.039 ) when performing Task A compared with feedback inducing an IF of attention . However , an order effect was present whereby performance was improved if an EF of attention was preceded by an IF of attention . CONCLUSIONS Feedback inducing an EF of attention may be of some benefit for improving motor performance of reaching in people with stroke in the short term ; however , these results should be interpreted with caution . Further research using a r and omised design is recommended to enable effects on motor learning to be assessed
target: VAF should be considered in the rehabilitation of lower extremity musculoskeletal dysfunctions .
  However , it can not be unequivocally confirmed that VAF is effective in this population , owing to study heterogeneity and a lack of high- quality evidence .
  Nevertheless , positive effects on lower extremity biomechanics and postural control have been identified .
background: BACKGROUND Verbal augmented feedback ( VAF ) is commonly used in physiotherapy rehabilitation of individuals with lower extremity musculoskeletal dysfunction or to induce motor learning for injury prevention .
  Its effectiveness for acquisition , retention and transfer of learning of new skills in this population is unknown .
  OBJECTIVES First , to investigate the effect of VAF for rehabilitation and prevention of lower extremity musculoskeletal dysfunction .
  Second , to determine its effect on motor learning and the stages of acquisition , retention and transfer in this population .