• Assessment of Knee Flexor and Extensor Muscle Balance

      Graham-Smith, P.; Jones, P.A.; Comfort, P.; Munro, Allan G. (2013)
    • Between-session reliability of four hop tests and the agility T-test

      Munro, Allan G.; Herrington, L.C. (2011)
      The purposes of this study were firstly to investigate whether learning affects were present in the administration of 4 hop tests and the Agility T-test and secondly to assess the between-session reliability of these tests. Twenty-two recreational athletes (11 women: age 22.3 ± 3.7 years, height 167.7 ± 6.2 cm, weight 59.2 ± 6.9 kg and 11 men: age 22.8 ± 3.1 years, height 179.8 ± 4 cm, weight 79.6 ± 10 kg) took part in the study. The subjects performed 6 repetitions of each hop test and 4 repetitions of the Agility T-test once a week over a period of 3 weeks. Distances were normalized to leg length and presented as a percentage value for the single, triple and crossover hop. Results showed that there were significant differences in scores between genders and that learning affects were present in all tests. Intraclass correlation coefficients ranged from 0.76 to 0.92 for the hop tests and 0.82 to 0.96 for the Agility T-test. The results indicated that the hop and Agility T-tests are reliable tests for use with subjects in a clinical or team sport environment. The error measurement statistics presented could be of help to practitioners to determine whether changes in individuals' scores in the hop and Agility T-tests are because of a true change in performance or measurement error. Of most importance was the fact that all subjects achieved at least 90% limb symmetry index on all 4 hop tests. Therefore, we recommend that a minimum limb symmetry value of 90%, rather than previously recommended 85%, should be adopted during rehabilitation and conditioning.
    • Between-session reliability of the star excursion balance test

      Munro, Allan G.; Herrington, L.C. (2010)
      Objective To assess the learning effect, test–retest reliability and measurement error associated with the SEBT. Design Repeated-measures study. Setting Controlled university laboratory environment. Participants Twenty-two healthy recreational athletes (11 male age 22.3 ± 3.7 years, 11 female age 22.8 ± 3.1 years). Main Outcome Measures Repeated-measures ANOVA assessed learning affects. Intraclass correlations coefficients, standard error of measurement and smallest detectable difference values were calculated to assess reliability and measurement error. Results Results showed that excursion distances stabilised after four trials, therefore trials five to seven were analysed for reliability. Test–retest reliability for all reach directions was high, with intraclass correlation coefficients ranging from 0.84 to 0.92. 95% confidence intervals, standard error of measurement and smallest detectable difference ranged from 77.84 to 94.00, 2.21–2.94% and 6.13–8.15%, respectively. Conclusion These statistics will allow clinicians to evaluate whether changes in SEBT scores are due to change in an individual’s performance or random error. The findings of this study show that the SEBT is a reliable measure of lower limb function in healthy recreational athletes. Changes in normalised scores of at least 6–8% are needed to feel confident that a real change in SEBT performance has occurred.
    • Comparison of landing knee valgus angle between female basketball and football athletes: Possible implications for anterior cruciate ligament and patellofemoral joint injury rates

      Munro, Allan G.; Herrington, L.C.; Comfort, P. (2012)
      Objective To evaluate landing strategies of female football and basketball athletes with relation to possible injury mechanisms and disparity in injury. Design Descriptive laboratory study. Participants 52 female football players and 41 female basketball players. Main outcome measures Frontal plane projection angle (FPPA) was measured during the single leg land (SLL) and drop jump (DJ) screening tasks. Results 2 × 2 × 2 mixed factorial ANOVA showed significant main effects were observed for sport, whilst significant interaction effects were seen between sport and task. Females in both sports exhibited significantly greater FPPA values during the SLL task than the DJ task (p < 0.001). Basketball players demonstrated significantly greater FPPA values during SLL than football players (p < 0.001), whilst no differences were found between sports in the DJ task (p = 0.328). Conclusion Female basketball players display greater FPPA values during unilateral landing tasks than female football players which may reflect the greater ACL injury occurrence in this population. Injury prevention programs in these athletes should incorporate unilateral deceleration and landing tasks and should consider the specific injury mechanisms in each sport.
    • Drop jump landing knee valgus angle; normative data in a physically active population

      Herrington, L.C.; Munro, Allan G. (2009)
      Objective Establish normative values for knee valgus angle during drop jump and step landings. Design Observational. Setting University biomechanics laboratory. Participants 100 physically active asymptomatic individuals (50 male, 50 female) aged 18–28 years old. Main outcome measures Knee valgus angle during drop jump and step landings. Results There were no differences between genders during the step landing task (p < 0.12) but there were differences during the drop jump landing task (p < 0.048). Both males and females showed no significant differences between sides for either of the tasks (p > 0.05) or between the valgus angle generated for either of the tasks (p > 0.05). Conclusion It would appear in order to be regarded as an average “normal” performance during a drop jump landing task knee valgus angle should be symmetrical and in the range of 7–13° for females and 3–8° for males. For a unilateral step landing task knee valgus angle should be symmetrical and in the range of 5–12° for females and 1–9° for males.
    • The effect of videotape augmented feedback on drop jump landing strategy: Implications for anterior cruciate ligament and patellofemoral joint injury prevention.

      Munro, Allan G.; Herrington, L.C. (2014-06)
      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.
    • Female Soccer: Part 1 – A Needs Analysis

      Turner, E.; Munro, Allan G.; Comfort, P. (2013)
      It is imperative for strength and conditioning coaches to conduct a detailed analysis of the demands of a sport, identifying normative data where possible to permit an evidence-based evaluation of an athlete’s current performance status and to inform the development of specific goals for the athletes’ development. Part one of this article reviews the demands of female soccer and provides normative data from published research identifying specific areas that require development in female soccer players. Part two recommends evidence-based approaches integrated to athlete development and injury prevention strategies, as a result of the needs analysis.
    • Female Soccer: Part 2 – Training Considerations and Recommendations

      Turner, E.; Munro, Allan G.; Comfort, P. (2013)
      Part 1 of this article identified the demands of female soccer and the specific areas of development required to optimize performance and reduce the risk of common injuries. Increases in aerobic capacity, strength, and lower limb control were required to improve performance and reduce the risks of common injuries. The aims of part 2 are to provide examples of evidence-based integrated strategies to address the issues identified in part 1 and to ensure not only enhanced performance but also a reduced incidence of common injuries in female soccer players.
    • Intra and inter-tester reliability of the tuck jump assessment

      Herrington, L.C.; Meyer, G.D.; Munro, Allan G. (2013)
      Objective To assess the inter-tester and intra-tester reliability of the tuck jump test. Design Repeated measures. Setting University Human Performance laboratory. Participants Five male and 5 female athletes undertook the Tuck jump test which was then assessed by two independent assessors. Main outcome measures Score from the video assessment of the tuck jump test by two independent assessors on two separate occasions. Results Average percentage of exact agreement (PEA) between the two testers across all scoring criteria for all subjects was 93% (range 80–100%). Both testers were in absolute 100% agreement in 5 out of 10 subjects for all of the scoring criteria. The kappa measure of agreement was k = 0.88 which is very good/excellent. The intra-tester PEA ranged 87.2%–100%, with kappa values of k = 0.86–1.0. Conclusion The study showed very good–excellent intra-tester and inter-tester reliability for both examiners when comparing their individual scores of the tuck jump test across two analysis sessions. These findings indicate that the proposed tuck jump assessment is reliable to identify abnormal landing mechanics.
    • Is There a Relationship Between Landing, Cutting, and Pivoting Tasks in Terms of the Characteristics of Dynamic Valgus?

      Jones, P.A.; Herrington, L.C.; Munro, Allan G.; Graham-Smith, P. (2014)
      Background: Anterior cruciate ligament (ACL) injuries are a major problem among female athletes. Screening for the risk of ACL injuries tends to focus on landing tasks, which may be limited in sports where changing direction is the main action involved in noncontact ACL injuries such as soccer. Purpose: To investigate whether there is a relationship between single-legged landing (SLL), cutting (90° cuts), and pivoting (180° turns) in terms of the characteristics of dynamic valgus. Study Design: Controlled laboratory study. Methods: Twenty female soccer players (mean ± SD: age, 21.0 ± 3.9 years; height, 1.65 ± 0.08 m; mass, 58.4 ± 6.4 kg) performed a minimum of 6 trials of SLL from a 0.3-m drop height and cutting and pivoting all on the right leg. Kinematics and kinetics were calculated from 3-dimensional motion analysis. Results: Strong correlations were found for peak knee abduction angles between tasks (R = 0.63-0.86, P < .01), whereas only moderate correlations between SLL and cutting (R = 0.46, P < .05), cutting and pivoting (R = 0.56, P < .05), and SLL and pivoting (R = 0.43, P > .05) were found between tasks for peak knee abduction moments. Conclusion: The results suggest that female athletes who exhibit poor SLL mechanics perform the same during various changing direction tasks. Clinical Relevance: The results support the use of existing screening tests that involve landing tasks to identify at-risk athletes for noncontact ACL injuries.
    • Reliability of 2-Dimensional Video Assessment of Frontal-Plane Dynamic Knee Valgus During Common Athletic Screening Tasks

      Munro, Allan G.; Herrington, L.C.; Carolan, M. (2012)
      Context: Two-dimensional (2D) video analysis of frontal-plane dynamic knee valgus during common athletic screening tasks has been purported to identify individuals who may be at high risk of suffering knee injuries such as anterior cruciate ligament tear or patellofemoral pain syndrome. Although the validity of 2D video analysis has been studied, the associated reliability and measurement error have not. Objective: To assess the reliability and associated measurement error of a 2D video analysis of lower limb dynamic valgus. Design: Reliability study. Participants: 20 recreationally active university students (10 women age 21.5 ± 2.3 y, height 170.1 ± 6.1 cm, weight 66.2 ± 10.2 kg, and 10 men age 22.6 ± 3.1 y, height 177.9 ± 6.0 cm, weight 75.8 ± 7.9 kg). Main Outcome Measurement: Within-day and between-days reliability and measurement-error values of 2D frontal-plane projection angle (FPPA) during common screening tasks. Interventions: Participants performed single-leg squat and drop jump and single-leg landings from a standard 28-cm step with standard 2D digital video camera assessment. Results: Women demonstrated significantly higher FPPA in all tests except the left single-leg squat. Within-day ICCs showed good reliability and ranged from .59 to .88, and between-days ICCs were good to excellent, ranging from .72 to .91. Standard error of measurement and smallest detectable difference values ranged from 2.72° to 3.01° and 7.54° to 8.93°, respectively. Conclusions: 2D FPPA has previously been shown to be valid and has now also been shown to be a reliable measure of lower extremity dynamic knee valgus. Using the measurement error values presented along with previously published normative data, clinicians can now make informed judgments about individual performance and changes in performance resulting from interventions.