Sensorimotor Dysfunction Following Anterior Cruciate Ligament Reconstruction- an Afferent Perspective: A Scoping Review.

Background: Sensorimotor dysfunction is thought to occur following anterior cruciate ligament (ACL) injury which may have implications on future reinjury risk. Dysfunction has been demonstrated within the efferent component of the sensorimotor system. However, no reviews have examined the two main components of the afferent system: the visual and somatosensory systems. Hypothesis/Purpose: This study aimed to report differences in function (central processing and local processing) within the (1) somatosensory and (2) visual systems between individuals following anterior cruciate ligament reconstruction (ACLR) and healthy controls (between-subject). The study also aimed to report differences in function within the two systems between the two limbs of an individual following ACLR (within-subject). Study Design: Scoping review. Methods: A search was conducted in PubMed, SPORTDiscus, CINAHL, Medline and Embase up until September 2021. Level I-IV studies assessing somatosensory and visual systems were included if they compared ACLR limbs to the uninjured contralateral limb (within-subject) or a healthy control limb (between-group). The function of somatosensory and visual systems was assessed across both central processing (processing of information in the central cortex) and local processing (all other assessments outside of central processing of information). Results: Seventy studies were identified (52 somatosensory, 18 visual). Studies examining somatosensory central processing demonstrated significant differences; 66% of studies exhibited within-subject differences and 100% of the studies exhibited between-group differences. Studies examining local somatosensory processing had mixed findings; 40% of the 'joint position sense (JPS)' and 'threshold to detect motion (TTDM)' studies showed significant within-subject differences (JPS=0.8°-3.8° and TTDPM=0.2°-1.4°) and 42% demonstrated significant between-group differences (JPS=0.4°-5° and TTDPM=0.3°-2.8°). Eighty-three percent of visual central processing studies demonstrated significant dysfunction between-groups with no studies assessing within-subject differences. Fifty percent of the studies examining local visual processing demonstrated a significant between-group difference. Conclusion: Significant differences in central processing exist within somatosensory and visual systems following ACLR. There is mixed evidence regarding local somatosensory and visual processing. Increased compensation by the visual system and local visual processing dysfunction may occur in conjunction with somatosensory dysfunction.

Current Concussion Knowledge, Beliefs, Education, and Management Practices Among Irish Post-Primary PE Teachers.

Purpose: Physical education (PE) teachers play an important role in concussion recognition and management in schools both in an academic and activity based setting. This study aimed to identify Irish post-primary PE teachers' concussion knowledge, beliefs, education and management practices. Methods:  An anonymous online survey, adapted to the Irish context from the validated BAKPAC-TEACH, was completed by 128 PE teachers (female = 74/123; 60.2%; male = 49/123; 39.8%, 36.1 ± 10.9 years), representing 4% of registered PE teachers in Ireland. Results: PE teachers reported 3.5 ± 4.7 students suffer with a sports-related concussion in their classroom annually and 43.9% previously had a student sustain a concussion during their PE class. Most received concussion education (58.6%), largely provided by sporting bodies. They frequently identified dizziness (93.0%) and headaches (92.2%) as concussion symptoms, but less commonly emotional (more emotional = 36.5%, nervous or anxious = 33.6%, sadness = 28.9%) or sleep (35.2%) symptoms. All PE teachers knew that a concussion requires immediate removal from a game/practice. PE teachers demonstrated less perceived knowledge and confidence relating to academic adjustments and return to learn criteria. Just 31.3% reported their school facilitates academic adjustments. Conclusion: Tailored concussion education addressing knowledge gaps highlighted in this study should be developed. A concussion policy and an academic support team in each school should be established and widely publicised to enhance the support of concussed students in returning to school.

The Running Injury Continuum: A qualitative examination of recreational runners' description and management of injury.

INTRODUCTION: A critical step in understanding and preventing running-related injuries (RRIs) is appropriately defining RRIs. Current definitions of RRIs may not represent the full process of injury development, failing to capture lower levels of injury that many athletes continue to train through. Understanding runners' description and management of the injury development process may allow for a more appropriate examination of all levels of injury. This study aimed to examine recreational runners' description and management of the injury development process. METHODS: A qualitative focus group study was undertaken. Seven semi-structured focus groups with male (n = 13) and female (n = 18) recreational runners took place. Focus groups were audio and video recorded, and transcribed verbatim. Transcripts were reflexively thematically analysed. A critical friend approach was taken to data coding. Multiple methods of trustworthiness were executed. RESULTS: Runners describe injury on a nine-level continuum, ranging from injury-free to career-ending injury. There are lower and higher levels of injury. Each level of injury is described across four categories of descriptors; physical description, outcome (effect on running and daily life), psychological description, and management. CONCLUSION: The Running Injury Continuum is a tool that can be used for injury surveillance (for healthcare professionals and researchers) and for research investigating RRI risk factors. Healthcare professionals, researchers and coaches must ensure they monitor the development of all levels of RRIs, across all categories of descriptors. Runners need to be educated regarding appropriate self-management strategies for lower level injuries, with access to evidence-based information being a critical management tool.

Running towards injury? A prospective investigation of factors associated with running injuries.

BACKGROUND: Given the high incidence and heavy burden of running related injuries, large-scale, prospective multifactorial investigations examining potential risk factors are warranted. This study aimed to identify factors associated with running related injuries and to evaluate their potential in injury screening. STUDY DESIGN: Prospective cohort study. MATERIALS AND METHODS: Two hundred and seventy-four recreational runners were recruited. Clinical measures (strength, range of motion, foot position), injury and training history (via questionnaire), impact loading (via accelerometery) and running technique measures were collected at baseline. Runners were tracked for injury for one year via fortnightly check-ins. A binary logistic regression, (injury versus no injury), was performed for each variable univariably, and then adjusting for age, sex and mileage. A multivariable regression was also performed to evaluate the model's discriminative ability. RESULTS: Of the 225 runners included in the final analysis 52% experienced a running related injury. Injury history in the past year, less navicular drop, and measures of running technique (knee, hip, and pelvis kinematics) were associated with increased odds of injury (p < .05). The multivariable logistic regression model was statistically significant, χ2(11) = 56.45, p < .001, correctly classifying 74% of cases with a sensitivity and specificity of 72% and 76%, respectively. The area under the receiver operating characteristic curve was 0.79 (CI95% = 0.73-0.85), demonstrating acceptable discriminative ability. CONCLUSIONS: This study found a number of clinical and running technique factors to be associated with prospective running related injuries among recreational runners. With the exception of injury history, the factors identified as being significantly associated with injury may be modifiable and therefore, could form the basis of interventions. Range of motion, spatiotemporal parameters and strength measures were not associated with injury and thus their utilisation in injury prevention practices should be reconsidered.

Aetiological Factors of Running-Related Injuries: A 12 Month Prospective "Running Injury Surveillance Centre" (RISC) Study.

BACKGROUND: Running-related injuries (RRIs) are a prevalent issue for runners, with several factors proposed to be causative. The majority of studies to date are limited by retrospective study design, small sample sizes and seem to focus on individual risk factors in isolation. This study aims to investigate the multifactorial contribution of risk factors to prospective RRIs. METHODS: Recreational runners (n = 258) participated in the study, where injury history and training practices, impact acceleration, and running kinematics were assessed at a baseline testing session. Prospective injuries were tracked for one year. Univariate and multivariate Cox regression was performed in the analysis. RESULTS: A total of 51% of runners sustained a prospective injury, with the calf most commonly affected. Univariate analysis found previous history of injury < 1 year ago, training for a marathon, frequent changing of shoes (every 0-3 months), and running technique (non-rearfoot strike pattern, less knee valgus, greater knee rotation) to be significantly associated with injury. The multivariate analysis revealed previous injury, training for a marathon, less knee valgus, and greater thorax drop to the contralateral side to be risk factors for injury. CONCLUSION: This study found several factors to be potentially causative of injury. With the omission of previous injury history, the risk factors (footwear, marathon training and running kinematics) identified in this study may be easily modifiable, and therefore could inform injury prevention strategies. This is the first study to find foot strike pattern and trunk kinematics to relate to prospective injury.

Movement Variability and Loading Characteristics in Athletes With Athletic Groin Pain: Changes After Successful Return to Play and Compared With Uninjured Athletes.

Background: Athletic groin pain (AGP) can lead to altered movement patterns during rapid deceleration and acceleration. However, the effect of AGP on movement variability and loading patterns during such actions remains less clear. Purpose: To investigate, using a continuous lateral hurdle hop task, how movement variability and magnitude measures of 3-dimensional (3D) kinematic, kinetic, and vertical ground-reaction force (vGRF) variables are (1) affected by AGP (AGP vs uninjured controls [CON]) and (2) changed after successful rehabilitation (AGP prerehabilitation vs AGP postrehabilitation vs CON). Study Design: Controlled laboratory study. Methods: A total of 36 athletes diagnosed with AGP and 36 uninjured CON athletes matched on age (18-35 years), level (subelite), and type of sports played (multidirectional field sport) performed a continuous lateral hurdle hop test that involved 10 side-to-side hops over a 15-cm hurdle. The 3D joint kinematic, kinetic, and vGRF variables (total, eccentric, and concentric; ground contact time, peak force, and impulse; and eccentric rate of force development) were examined. The AGP and CON groups were tested at baseline, and the AGP group was retested after participants successfully completed a standardized, exercise-based rehabilitation program targeting intersegmental control. Results: There were no differences in baseline characteristics between the AGP (mean ± SD: age, 27.5 ± 4.8 years; height, 179.8 ± 6.3 cm; mass, 80.3 ± 7.1 kg) and CON (mean ± SD: age, 24.1 ± 4.5 years; height, 181.0 ± 5.8 cm; mass, 80.4 ± 8.2 kg) groups. At baseline, athletes with AGP demonstrated altered loading patterns in the vGRF (longer ground contact times, reduced peak force, and reduced rate of force development) compared with CON athletes, while no significant difference in any movement variability variables was evident. After rehabilitation, the athletes with AGP demonstrated significant changes in transverse and coronal plane hip and trunk kinematics, with no significant differences in vGRF variables compared with the CON group. Conclusion: The differences in baseline vGRF measures between the AGP and CON groups were no longer evident after athletes with AGP underwent rehabilitation. No differences in movement variability were evident between the AGP and CON groups, either before or after rehabilitation. Clinical Relevance: Rehabilitation programs should consider targeting intersegmental hip and trunk movement patterns to positively influence loading patterns in athletes with AGP.

Comparison of impact accelerations between injury-resistant and recently injured recreational runners.

INTRODUCTION/PURPOSE: Previous injury has consistently been shown to be one of the greatest risk factors for running-related injuries (RRIs). Runners returning to participation following injury may still demonstrate injury-related mechanics (e.g. repetitive high impact loading), potentially exposing them to further injuries. The aim of this study was to determine if the magnitude (Peakaccel) and rate of loading (Rateaccel) at the tibia and sacrum differ between runners who have never been injured, those who have acquired injury resistance (runners who have not been injured in the past 2 years) and those who have been recently injured (RRI sustained 3-12 months ago). METHODS: Runners completed an online survey capturing details of their RRI history over the previous 2 years. Never injured runners were matched by sex, quarterly annual mileage and typical training speed to runners who had acquired injury resistance and to runners who had been recently injured. Differences in Peakaccel and Rateaccel of the tibia and sacrum were assessed between the three groups during a treadmill run at a set speed, with consideration for sex. RESULTS: A total of 147 runners made up the three injury status groups (n: 49 per group). There was a significant main effect of injury status for Peakaccel and Rateaccel at the sacrum, with recently injured runners demonstrating significantly greater Rateaccel than never injured and acquired injury resistant runners. There was also a significant main effect for sex, with females demonstrating greater tibial Peakaccel, sacrum Peakaccel and Rateaccel than males. CONCLUSION: Rateaccel at the sacrum distinguishes recently injured runners from never injured runners and runners who may have acquired injury resistance, potentially highlighting poor impact acceleration attenuation in recently injured runners.

Post-injury fear-avoidance and confidence in readiness to return to sport in Irish collegiate athletes.

Fear avoidance and low confidence in their ability to return to sport can impede athletes' subsequent recovery and return to sport. This study aimed to identify fear avoidance and confidence in readiness to return to sport following injury in Irish collegiate athletes. Male (416) and female (256) athletes from 24 field-sport teams at one university were prospectively followed for one season. The Athlete Fear Avoidance Questionnaire (AFAQ) and pain on the Visual Analogue Scale was completed following a time-loss injury. Prior to return to sport, participants completed the AFAQ and the Injury Psychological Readiness to Return to Sport (I-PRRS). We recorded 179 injuries. Fear avoidance was evident post-injury (21.8 ± 6.7), and the mean total I-PRRS score was 48.4 ± 8.9. Those with severe injuries presented with higher fear avoidance and lower confidence. Higher pain was associated with greater fear avoidance following injury (r = 0.32, p < 0.0001), prior to return to sport (r = 0.38, p < 0.0001), and with lower confidence (r = -0.27, p < 0.0001).   Low confidence and fear avoidance was identified, particularly in those with a severe injury or high pain levels. Identifying, and providing psychosocial support to athletes experiencing, these issues is recommended.

Are impact accelerations during treadmill running representative of those produced overground?

BACKGROUND: Although many runners train overground, measuring impact accelerations on a treadmill may be advantageous for researchers and clinicians. Previous investigations of peak and rate of acceleration (peakaccel, rateaccel) during treadmill running compared to overground running have not examined both the relative consistency and absolute agreement of these measures, or the effect of treadmill stiffness. RESEARCH QUESTION: (1) Are peakaccel and rateaccel produced during running on a stiff and less stiff treadmill 'representative' of those produced during overground running? (2) Are peakaccel and rateaccel measured on treadmills of different stiffness 'representative' of each other? METHODS: Eighteen participants ran at a self-selected pace on three surfaces: Treadmill 1 (reduced stiffness), Treadmill 2 (increased stiffness) and overground on asphalt, whilst peakaccel and rateaccel were recorded at the shank and lower back. Relative consistency (ICC (3,1)), absolute agreement (Bland-Altman analysis) and systematic differences (ANOVA/Friedman's Tests) were assessed. RESULTS: ICCs revealed moderate to excellent relative consistency in peakaccel and rateaccel between surfaces, with higher consistency for measures at the lower back. Absolute agreement was low, with the Bland Altman limits of agreement exceeding the clinical acceptable range for all comparisons. For systematic differences in means, peakaccel and rateaccel at the shank were significantly higher overground than on either treadmill; with no difference evident at the lower back. No differences were found for surface with respect to shank or lower back peakaccel and rateaccel between treadmills. SIGNIFICANCE: Moderate to excellent relative consistency of peakaccel and rateaccel between the surfaces suggests that using different surfaces in research involving rank ordering of participants by acceleration magnitude may be acceptable (e.g. prospective studies examining if impact accelerations are related to injury). However, low absolute agreement indicates that data collected on treadmills of different stiffness and overground should not be used interchangeably (e.g. running-retraining studies).

A qualitative examination of the factors affecting the adoption of injury focused wearable technologies in recreational runners.

PURPOSE: Understanding the perceived efficacy and ease of use of technologies will influence initial adoption and sustained utilization. The objectives of this study were to determine the metrics deemed important by runners for monitoring running-related injury (RRI) risk, and identify the facilitators and barriers to their use of injury focused wearable technologies. METHODS: A qualitative focus group study was undertaken. Nine semi-structured focus groups with male (n = 13) and female (n = 14) recreational runners took place. Focus groups were audio and video recorded, and transcribed verbatim. Transcripts were thematically analysed. A critical friend approach was taken to data coding, and multiple methods of trustworthiness were executed. RESULTS: Excessive loading and inadequate recovery were deemed the most important risk factors to monitor for RRI risk. Other important factors included training activities, injury status and history, and running technique. The location and method of attachment of a wearable device, the design of a smartphone application, and receiving useful injury-related information will affect recreational runners' adoption of injury focused technologies. CONCLUSIONS: Overtraining, training-related and individual-related risk factors are essential metrics that need to be monitored for RRI risk. RRI apps should include the metrics deemed important by runners, once there is supporting evidence-based research. The difficulty and/or ease of use of a device, and receiving useful feedback will influence the adoption of injury focused running technologies. There is a clear willingness from recreational runners to adopt injury focused wearable technologies whilst running.

Relative and absolute reliability of shank and sacral running impact accelerations over a short- and long-term time frame.

Whilst running is hugely popular, running-related injuries (RRIs) are prevalent. High impact loading has been proposed to contribute to RRIs, with accelerometers becoming increasingly popular in estimating segmental loading for injury detection and biofeedback training. However, there is a lack of research examining the reliability of measures of impact acceleration across short- and long-term time periods, both prior to and following exerted running. The aim of this study was to assess the absolute and relative reliability of shank and sacral impact accelerations over a short- and long-term time period. Peak (Peakaccel) and rate (Rateaccel) of impact acceleration at the shank and sacrum were assessed in 18 recreational runners over short- and long-term time frames, across fixed and self-selected speeds. The relative and absolute reliabilities were investigated for pre- and post-exerted states of running. There was high-to-excellent relative reliability, and predominantly moderate absolute reliability for shank and sacrum Peakaccel and Rateaccel in the short- and long-term time frames between pre- and post-exerted states. High to excellent relative reliability of Peakaccel and Rateaccel at the shank and sacrum are appropriate and acceptable measures across short- and long-term time frames. These findings were consistent with different levels of speed and exertion. The minimal detectable change % was large for both sensors and associated measurements, indicating that their use may be limited to intervention studies that elicit large change (>30%) in these measures.

Development of an Internet of Things Technology Platform (the NEX System) to Support Older Adults to Live Independently: Protocol for a Development and Usability Study.

BACKGROUND: In a rapidly aging population, new and efficient ways of providing health and social support to older adults are required that not only preserve independence but also maintain quality of life and safety. OBJECTIVE: The NEX project aims to develop an integrated Internet of Things system coupled with artificial intelligence to offer unobtrusive health and wellness monitoring to support older adults living independently in their home environment. The primary objective of this study is to develop and evaluate the technical performance and user acceptability of the NEX system. The secondary objective is to apply machine learning algorithms to the data collected via the NEX system to identify and eventually predict changes in the routines of older adults in their own home environment. METHODS: The NEX project commenced in December 2019 and is expected to be completed by August 2022. Mixed methods research (web-based surveys and focus groups) was conducted with 426 participants, including older adults (aged ≥60 years), family caregivers, health care professionals, and home care workers, to inform the development of the NEX system (phase 1). The primary outcome will be evaluated in 2 successive trials (the Friendly trial [phase 2] and the Action Research Cycle trial [phase 3]). The secondary objective will be explored in the Action Research Cycle trial (phase 3). For the Friendly trial, 7 older adult participants aged ≥60 years and living alone in their own homes for a 10-week period were enrolled. A total of 30 older adult participants aged ≥60 years and living alone in their own homes will be recruited for a 10-week data collection period (phase 3). RESULTS: Phase 1 of the project (n=426) was completed in December 2020, and phase 2 (n=7 participants for a 10-week pilot study) was completed in September 2021. The expected completion date for the third project phase (30 participants for the 10-week usability study) is June 2022. CONCLUSIONS: The NEX project has considered the specific everyday needs of older adults and other stakeholders, which have contributed to the design of the integrated system. The innovation of the NEX system lies in the use of Internet of Things technologies and artificial intelligence to identify and predict changes in the routines of older adults. The findings of this project will contribute to the eHealth research agenda, focusing on the improvement of health care provision and patient support in home and community environments. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/35277.

Can Directed Compliant Running Reduce the Magnitude of Variables Associated With the Development of Running Injuries?

ABSTRACT: Ó Catháin, CP, Richter, C, and Moran, K. Can directed compliant running reduce the magnitude of variables associated with the development of running injuries? J Strength Cond Res 36(3): 772-780, 2022-Running is one of the most popular modes of activity worldwide and provides numerous health benefits. However, impact forces associated with the foot contacting the ground have been implicated in the development of running related injuries. As such, previous studies have used various methods to alter running to reduce the magnitude of these impact forces. However, it is unclear what kinematic changes facilitate this reduced loading or how loading further up the body changes. In this study, verbal direction was used to teach subjects to run with a more compliant running technique. Kinetic and kinematics characteristics of each subjects "normal" running technique and new "compliant technique" were measured in a fatigued and unfatigued state. Energy expenditure of each running style was also measured. Verbally directed compliant running significantly decreased (17%) vertical ground reaction force impact peaks, sacral (41%) and head (28%) impact accelerations, and increased energy expenditure (21%), in comparison with normal running. Findings suggest that verbally directed compliant running may reduce the magnitude of variables associated with the development of running injuries.

Does stammering act as a barrier to exercise and sport in Irish adults who stammer?

PURPOSE: Exercise and sport participation lead to many physical and psychosocial benefits. However, barriers to exercise and sporting participation exist. This study aims to examine if stammering acts as a barrier to exercise and sporting participation in adults. METHODS: One hundred and six adults who stammer (male n = 74, female n = 32; 33.83 ± 14.5 years) completed an anonymous questionnaire which evaluated their stammering history, exercise and sporting participation, views on why they exercise, whether stammering prevented or negatively influenced their participation in exercise or sport. Descriptive statistics were then calculated. RESULTS: The majority (90.6 %) of participants take part in some form of exercise/sport. However, their stammer prevented them from taking part in a specific exercise/sport at least once (49.1 %), due to being too nervous to introduce themselves, nervous or fear of stammering or being judged. Their stammer also negatively impacted their involvement when participating at least once (42.4 %), with not feeling part of the team and fear of speaking reported. Self-disclosure of their stammer and improving awareness of stammering were identified as common facilitators for taking part in exercise/sport. CONCLUSION: Stammering was not found to impact general participation in exercise and sport but was identified as a barrier to partaking in specific exercise and sport and their enjoyment thereof. Encouraging those who stammer to inform those involved in sport and exercise (e.g. fellow players, coaches) about their stammer and improving stammer awareness across the general and sporting population may encourage further participation in exercise and sport in those who stammer.

Risk Factors for Injuries in Runners: A Systematic Review of Foot Strike Technique and Its Classification at Impact.

BACKGROUND: It has been suggested that foot strike technique (FST) at initial contact is related to running-related injuries (RRIs). PURPOSE: To explore the relationship between FST and RRIs. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: A systematic electronic search was performed using MEDLINE, PubMed, SPORTDiscus, Scopus, and Web of Science databases. Included were studies published in the English language that explored the relationship between FST and RRIs between January 1960 and November 2020. Results were extracted and collated. The Grading of Recommendations, Assessment, Development and Evaluation approach was applied to synthesize the quality of evidence. RESULTS: We reviewed 13 studies exploring the relationship between FST and RRIs. Of these, 6 studies reported FST categorically (foot strike pattern [FSP]), and 7 reported continuous measures (foot contact angle, ankle flexion angle, and strike index). Three of the 6 studies looking at categorical FSP found rearfoot strikers have a significantly greater retrospective injury rate than do non- rearfoot strikers, with 1 other study noting a greater risk associated with midfoot and forefoot strike. Regarding the continuous measures of FST, only 1 of the 7 studies reported a significant relationship with RRIs. CONCLUSION: There was low evidence to suggest a relationship between FST (or its subcategories of categorical FSP and continuous measures) and RRIs. While two-thirds of the categorical studies found a relationship between FSP and RRIs, these studies were very low quality, with limitations such as retrospective study design, low participant numbers, and poor FSP assessment methods. More large-scale prospective studies are required.

Hip Muscle Strength Explains Only 11% of the Improvement in HAGOS With an Intersegmental Approach to Successful Rehabilitation of Athletic Groin Pain.

BACKGROUND: Exercise-based rehabilitation targeting intersegmental control has high success rates and fast recovery times in the management of athletic groin pain (AGP). The influence of this approach on hip strength and lower limb reactive strength and how these measures compare with uninjured athletes (CON) remain unknown. Additionally, the efficacy of this program after return to play (RTP) has not been examined. PURPOSE: First, to examine differences in isometric hip strength, reactive strength, and the Hip and Groin Outcome Score (HAGOS) between the AGP and CON cohorts and after rehabilitation; second, to examine the relationship between the change in HAGOS and the change in strength variables after rehabilitation; last, to track HAGOS for 6 months after RTP. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 42 athletes diagnosed with AGP and 36 matched controls completed baseline testing: isometric hip strength, lower limb reactive strength, and HAGOS. After rehabilitation, athletes with AGP were retested, and HAGOS was collected at 3 and 6 months after RTP. RESULTS: In total, 36 athletes with AGP completed the program with an RTP time of 9.8 ± 3.0 weeks (mean ± SD). At baseline, these athletes had significantly lower isometric hip strength (abduction, adduction, flexion, extension, external rotation: d = -0.67 to -1.20), single-leg reactive strength (d = -0.73), and HAGOS (r = -0.74 to -0.89) as compared with the CON cohort. Hip strength (d = -0.83 to -1.15) and reactive strength (d = -0.30) improved with rehabilitation and were no longer significantly different between groups at RTP. HAGOS improvements were maintained or improved in athletes with AGP up to 6 months after RTP, although some subscales remained significantly lower than the CON group (r = -0.35 to -0.51). Two linear regression features (hip abduction and external rotation) explained 11% of the variance in the HAGOS Sports and Recreation subscale. CONCLUSION: Athletes with AGP demonstrated isometric hip strength and reactive strength deficits that resolved after an intersegmental control rehabilitation program; however, improved hip strength explained only 11% of improvement in the Sports and Recreation subscale. HAGOS improvements after pain-free RTP were maintained at 6 months.

Do Injury-Resistant Runners Have Distinct Differences in Clinical Measures Compared with Recently Injured Runners?

INTRODUCTION: Although lower extremity muscle strength, joint motion, and functional foot alignment are commonly used, time-efficient clinical measures that have been proposed as risk factors for running-related injuries, it is unclear if these factors can distinguish injury resistance in runners. PURPOSE: This study compares clinical measures, with consideration of sex, between recently injured runners (3 months to 1 yr prior), those with a high level of injury resistance who have been uninjured for at least 2 yr, and never-injured runners. METHODS: Averaged bilateral values and between-limb symmetry angles of lower limb isometric muscle strength, joint motion, navicular drop, and foot posture index (FPI) were assessed in a cohort of recreational runners, and their injury history was recorded. Differences in clinical measures between injury groupings were examined, with consideration of sex. RESULTS: Of the 223 runners tested, 116 had been recently injured, 61 had been injured >2 yr ago and were deemed to have acquired reinjury resistance, and 46 were never injured. Plantarflexion was greater in both recently injured (P = 0.001) and acquired reinjury resistance runners (P = 0.001) compared with never-injured runners. Recently injured runners displayed higher hip abduction strength compared with never-injured runners (P = 0.019, η2 = 0.038, small effect size). There were no statistically significant differences in the remaining measures between the injury groupings. With the exception of FPI, there was no interaction between sex and injury grouping for any of the measures. CONCLUSION: Commonly used clinical measures of strength, joint motion, and functional foot alignment were not superior in injury-resistant runners compared with recently injured runners, questioning their relevance in identifying future injury resistance of runners.

Fear Avoidance After Injury and Readiness to Return to Sport in Collegiate Male and Female Gaelic Games Players.

BACKGROUND: Injuries are common in collegiate Gaelic games, and negative psychological responses to injury, such as fear avoidance and a lack of psychological readiness to return to sport, can affect players during their rehabilitation and their subsequent return to sport. Thus, identifying these responses in players can allow clinicians to address these issues during rehabilitation. This study aimed to examine fear avoidance and psychological readiness to return to sport in collegiate Gaelic games players. HYPOTHESIS: Collegiate Gaelic games players will experience similar levels of fear avoidance and psychological readiness to return to sport as other adult athletes. STUDY DESIGN: Cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Male (n = 150) and female (n = 76) players from 1 Irish collegiate institution were recruited. Players that were injured over 1 collegiate season completed the Athlete Fear Avoidance Questionnaire (AFAQ) immediately after the injury and the Injury-Psychological Readiness to Return to Sport (I-PRRS) Scale once cleared to return to sport. An injury report form was also completed. The overall AFAQ (sum of 10 items) and I-PRRS (sum of 6 items/10) scores were calculated. RESULTS: Seventy-three injuries (n = 73) occurred, and injured players had a mean overall AFAQ and I-PRRS score of 22.6 ± 5.3 and 46.4 ± 8.8, respectively. Just less than half (47.9%) of players were deemed psychologically unready to return to sport when cleared physically. After severe injuries, significantly higher overall AFAQ scores than mild injuries (P = 0.01) and lower overall I-PRRS than moderate injuries (P < 0.0001) was noted. For the overall scores, no gender differences were observed. CONCLUSION: Fear avoidance and lowered confidence levels before return to sport occurs in collegiate Gaelic games players similar to other student-athletes. CLINICAL RELEVANCE: Identification of fear avoidance or low readiness to return to sport, particularly after serious injury, is important to implement psychosocial support during their rehabilitation.

Principal Component Analysis of the Associations Between Kinetic Variables in Cutting and Jumping, and Cutting Performance Outcome.

ABSTRACT: Welch, N, Richter, C, Moran, K, and Franklyn-Miller, A. Principal component analysis of the associations between kinetic variables in cutting and jumping, and cutting performance outcome. J Strength Cond Res 35(7): 1848-1855, 2021-The primary aim of this study was to determine which features within the ground reaction force (GRF) trace during cutting are related to performance outcome in different angled cuts. The secondary aim was to understand the relationship between GRF features in a series of maximum strength, explosive strength, and reactive strength tests, and cutting performance outcome. Twenty-five male intercounty Gaelic football players (23.5 ± 4.2 years, 183 ± 6 cm, and 83 ± 6.9 kg) participated in the study. Subjects completed 110 and 45° cutting tasks, single leg squat jumps, drop landings, drop jumps, and isometric midthigh pulls. A principal component (PC) analysis and simulation approach were applied to the data and correlations between PCs and cutting performance outcome measured. Lower vertical to horizontal impulse ratios (r = -0.70 to -0.46) in both cuts and greater forces over the first 50 ms of ground contact (r = -0.44) in the 110° cut correlated with enhanced cutting performance outcomes. Greater reactive strength index and height in the drop jump (r = -0.51 and -0.54) and greater impulses over the first 25 ms of ground contact in the drop landing (r = 0.49 and 0.70) correlated with enhanced cutting performance outcomes. These results highlight the importance of greater horizontal and rapid force production in cutting and greater reactive strength qualities to enhance cutting performance.

The Effect of Hip Extension and Nordic Hamstring Exercise Protocols on Hamstring Strength: A Randomized Controlled Trial.

ABSTRACT: Whyte, EF, Heneghan, B, Feely, K, Moran, KA, and O'Connor, S. The effect of hip extension and Nordic hamstring exercise protocols on hamstring strength: A randomized controlled trial. J Strength Cond Res 35(10): 2682-2689, 2021-Lower and between-limb asymmetrical eccentric hamstring isokinetic strength may be associated with hamstring injuries, which mainly affect the biceps femoris. The 45° hip extension exercise (HEE) strengthens the hamstrings in the lengthened position where the biceps femoris experiences greatest loading during high-speed running. However, the effect of an HEE program on eccentric hamstring isokinetic strength has not been investigated or compared with the Nordic Hamstring Exercise (NHE) program. Twenty-four male, varsity, Gaelic footballers (22.4 ± 2.7 years; 182.1 ± 6.0 cm; 84.4 ± 7.9 kg) were randomly allocated to an HEE or NHE 4-week program. Isokinetic (60°·s-1) eccentric peak torque, functional hamstring-to-quadriceps ratio, and between-limb eccentric strength (absolute and percentage) asymmetries were recorded before and after intervention. Muscle soreness scores were reported after exercise using a visual analogue scale. A mixed between-within analysis of variance investigated group (HEE vs. NHE) by time (pre vs. post) interaction effects, and any main effects. An independent-samples t-test compared muscle soreness scores between the NHE and HEE groups. No interaction or group main effects were found. Main effects for time were observed on dominant and nondominant limbs for eccentric peak torque (p < 0.001, η2 = 0.21, p = 0.01, η2 = 0.51, respectively) and functional hamstring quadriceps ratio (p = 0.03, η2 = 0.59, p < 0.0001, η2 = 0.26, respectively). There were no main effects for time between-limb eccentric peak torque or percentage asymmetries (p = 0.41, η2 = 0.03, p = 0.20, η2 = 0.07, respectively), or differences in muscle soreness scores (p > 0.05). A 4-week HEE program increases eccentric hamstring isokinetic strength similar to a NHE program, which may be useful as part of a hamstring injury prevention program.