Ankle-dorsiflexion range of motion and landing biomechanics

Knee Muscles Strength Can be Improved by Using an Elastic Band as an Assistive Device for Knee-Ankle Complex

BACKGROUND There are various tools and methods used for strength exercise. Elastic bands, one of the resistance exercise tools, have been used for various purposes, including muscle strengthening; however, there is very little evidence supporting their efficacy. The study was performed to investigate the effect of knee-ankle elastic bands on knee muscle strength-related parameters according to sex in healthy adults. MATERIAL AND METHODS This was a cross-sectional study. Twenty-one participants (11 female and 10 male) were studied using a cross-over design. Isokinetic concentric knee extension and flexion strength was measured at 60°/s and 180°/s with and without application of a therapeutic elastic band in the shape of an "8", with knee flexion and ankle dorsiflexion. The variables related to muscle power automatically calculated in the protocol of the isokinetic system were compared according to sex and angular velocity. RESULTS Peak moment (PM), PM/body weight, average power, total work, and the agonist/antagonist ratio, demonstrated significant improvement (P<0.05) at both 60°/s and 180°/s "with" compared to "without" the elastic band according to sex. CONCLUSIONS The use of therapeutic elastic bands in the shape of a figure 8 with knee flexion and ankle dorsiflexion may be used as assistive devices for improving strength in muscles supporting the knee. Further high-quality studies are needed to assess the potential of elastic bands as assistive devices and not merely as exercise tools. Therapeutic elastic bands in the shape of an "8" with knee flexion and ankle dorsiflexion may be useful in sports activities.

Risk factors for the occurrence and protraction of patellar and patellar tendon pain in children and adolescents: a prospective cohort study of 3 years

Background

Patellar and patellar tendon pain is a common limitation to children’s participation in social and physical activities. Some factors have been implicated in the occurrence and protraction of knee pain, but the causal relationship is unknown. The purpose of this study was to investigate whether participants’ physical characteristics and activity level are risk factors for the occurrence and protraction of patellar and patellar tendon pain in children and adolescents.

Methods

A three-year prospective cohort study was conducted with healthy students who were aged 8–14 years old, in Japan. Height, weight, heel-buttock distance, straight leg raising angle, and dorsiflexion angle of the ankle joint were collected as individual physical factors at the beginning of each year. The presence of self-reported patellar and patellar tendon pain and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) was collected every month. Protraction was defined as either (1) pain lasting for more than three continuous months or (2) recurrent pain after more than three months of complete recovery. Participants who did not have any pain at the beginning of the observation period were included in the analysis. We analyzed the odds ratio (OR) of pain occurrence within a year of registration and protraction throughout the study period for all physical factors and HSS Pedi-FABS.

Results

We included 1133 participants in the analysis and 252 participants developed knee pain within a year. 34.8% of participants with pain experienced protraction during the follow-up period. A high HSS Pedi-FABS significantly predicted knee pain occurrence (OR 1.03, 95% confidence interval [CI] 1.01–1.05) and protraction (OR 1.03, 95% CI 1.00–1.05). In addition, younger children and girls were at a significantly higher risk of patellar and patellar tendon pain protraction (age, OR 0.81, 95% CI, 0.73–0.90; sex, OR 1.69, 95% CI, 1.09–2.64). Other physical factors did not significantly predict the occurrence or protraction of knee pain.

Conclusions

This study showed that a greater physical activity level was a risk factor for the occurrence and protraction of patellar and patellar tendon pain in childhood. In addition, younger age and female sex predicted higher risk of protraction of pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05349-y.

Association Between the Functional Movement Screen and Landing Kinematics in Individuals With and Without Anterior Cruciate Ligament Reconstruction

OBJECTIVES

The purpose of this study was to compare functional movement screen (FMS) scores and drop vertical jump (DVJ) kinematics between those with and without anterior cruciate ligament reconstruction (ACLR), and to evaluate the association between FMS composite score and DVJ kinematics.

DESIGN

Cross-sectional.

PARTICIPANTS

Sixty individuals with and without a history of ACLR.

MAIN OUTCOME MEASURES

Composite FMS score and the dorsiflexion, knee-flexion, hip-flexion, knee abduction, hip adduction, and trunk-flexion angles during a DVJ.

RESULTS

The FMS scores did not differ between groups (P > .05). There were smaller peak and initial contact hip-flexion angles in the ACLR and contralateral limbs compared with controls, and smaller peak dorsiflexion angles in the ACLR compared with contralateral limbs (P < .05). Lower FMS score was associated with a smaller peak dorsiflexion angle, smaller peak knee-flexion angle, and larger peak knee abduction angle in the ACLR limb (ΔR2 = .14-.23); a smaller peak dorsiflexion angle and smaller peak knee-flexion angle in the contralateral limb (ΔR2 = .17-.19); and a smaller peak dorsiflexion angle, smaller peak knee-flexion angle, and larger peak knee abduction angle in the control limb (ΔR2 = .16-.22).

CONCLUSION

The FMS scores did not differ between groups, but were associated with DVJ kinematics and should be a complementary rather than substitute assessment.

Validity and inter-rater reliability of ankle motion observed during a single leg squat

BACKGROUND

The single leg squat (SLS) test is a clinical functional test commonly used to evaluate clinically aberrant movement patterns of the knee. The SLS could be an interesting option to analyze ankle control in the frontal plane during dynamic load analysis. However, to date, there are no studies that have analyzed the associations between the increased subtalar joint pronation by navicular drop (ND) test and ankle control with single leg squat (SLS_ankle) using a three-point scale. The purpose of this study was to evaluate the reliability of a clinical observation method to assess and determine the relationship between navicular drop (ND) and ankle control on the SLS_ankle score.

METHODS

A total of fifty-five healthy, physically active (31 females and 24 males) volunteers participated in this study. The degree of subtalar pronation was assessed through the ND test, and the ankle control was defined as the ankle displacement in the frontal plane during the SLS.

RESULTS

We found good intra-rater and inter-rater agreement during SLS_ankle, with Kappa values from 0.731 to 0.750. The relationship between the SLS_ankle and ND was significant ; the Spearman's rank correlation coefficient was 0.504 (p < 0.05).

CONCLUSIONS

The SLS_ankle score supplied the clinical practice with a reliable and valid alternative for quantifying foot mobility in comparison to the ND test.

Chronic and Residual Effects of a Two-Week Foam Rolling Intervention on Ankle Flexibility and Dynamic Balance

Background

Foam rolling has been shown to acutely improve joint range of motion (ROM). However, limited knowledge exists on the chronic and residual effects. The primary purpose of this study was to examine the chronic and residual effects of a 2-week roller–massager intervention on ankle dorsiflexion ROM and dynamic balance.

Methods

Forty-two participants (24.3 ± 2.5 years, 33 males, 9 females) were randomly assigned to either roller-massage (RM) or control group (= no intervention). Ankle ROM was assessed with the weight-bearing lunge test (WBLT) and dynamic balance with the Y-Balance test for both limbs. The RM group was instructed to roll their calf muscles for three sets of 60 s per leg on 6 days a week over 2 weeks. Acute effects were measured during baseline testing for dorsiflexion ROM and dynamic balance immediately after foam rolling. Chronic and residual effects were measured 1 day and 7 days after the intervention period. Multivariate ANOVA was performed for post-hoc comparisons to determine acute, chronic, and residual effects.

Results

Significant acute and chronic foam rolling effects (p <0.05) were found for ankle dorsiflexion ROM. The chronic increase in ROM slightly decreased 7 days post-intervention but remained significantly above baseline (p < 0.05). Regarding dynamic balance, there were no acute but chronic (p < 0.05) and residual (p < 0.05) effects.

Conclusion

Using a roller–massager for a 2-week period chronically increases ROM and dynamic balance. These increases are still significant 7 days post-intervention emphasizing the sustainability of foam rolling effects.

Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.

Immediate Effect of Ankle Mobilization on Range of Motion, Dynamic Knee Valgus, and Knee Pain in Women With Patellofemoral Pain and Ankle Dorsiflexion Restriction: A Randomized Controlled Trial With 48-Hour Follow-Up

CONTEXT

Restriction in ankle dorsiflexion range of motion (ROM) has been previously associated with excessive dynamic knee valgus. This, in turn, has been correlated with knee pain in women with patellofemoral pain.

OBJECTIVES

To investigate the immediate effect of 3 ankle mobilization techniques on dorsiflexion ROM, dynamic knee valgus, knee pain, and patient perceptions of improvement in women with patellofemoral pain and ankle dorsiflexion restriction.

DESIGN

Randomized controlled trial with 3 arms.

SETTING

Biomechanics laboratory.

PARTICIPANTS

A total of 117 women with patellofemoral pain who display ankle dorsiflexion restriction were divided into 3 groups: ankle mobilization with anterior tibia glide (n = 39), ankle mobilization with posterior tibia glide (n = 39), and ankle mobilization with anterior and posterior tibia glide (n = 39).

INTERVENTION(S)

The participants received a single session of ankle mobilization with movement technique.

MAIN OUTCOME MEASURES

Dorsiflexion ROM (weight-bearing lunge test), dynamic knee valgus (frontal plane projection angle), knee pain (numeric pain rating scale), and patient perceptions of improvement (global perceived effect scale). The outcome measures were collected at the baseline, immediate postintervention (immediate reassessment), and 48 hours postintervention (48 h reassessment).

RESULTS

There were no significant differences between the 3 treatment groups regarding dorsiflexion ROM and patient perceptions of improvement. Compared with mobilization with anterior and posterior tibia glide, mobilization with anterior tibia glide promoted greater increase in dynamic knee valgus (P = .02) and greater knee pain reduction (P = .02) at immediate reassessment. Also compared with mobilization with anterior and posterior tibia glide, mobilization with posterior tibia glide promoted greater knee pain reduction (P < .01) at immediate reassessment.

CONCLUSION

In our sample, the direction of the tibia glide in ankle mobilization accounted for significant changes only in dynamic knee valgus and knee pain in the immediate reassessment.

Evaluating the Effectiveness of Soft Tissue Therapy in the Treatment of Disorders and Postoperative Conditions of the Knee Joint-A Systematic Review

The term "soft tissue therapy" (STT) refers to mechanical methods of treatment involving passive kneading, pressing and stretching of pathologically tense tissues in supporting the process of recovery after surgery or trauma to the musculoskeletal system. The objective of this study was to review current scientific reports evaluating the effectiveness of the use of STT in patients with diseases or after surgical procedures of the knee joint. A systematic search of the popular scientific databases PubMed, Scopus and Embase was performed from inception to 15 October 2021. Eight articles met eligibility criteria and were included in the review. Six papers were related to disorders of the knee joint, while the remaining two studies were related to dysfunctions associated with the conditions after surgical intervention. The findings presented confirmed the effectiveness of STT in orthopaedic patients who showed an increase in lower limb functional parameters. The research has shown that the use of various methods of STT has a significant impact on increasing muscle activity and flexibility as well as increasing the range of motion in the knee joint. The physiotherapeutic methods used had a significant impact on reducing pain and increasing physical function and quality of life. The techniques used reduced the time to descend stairs in patients with knee osteoarthritis. This review summarises the effectiveness of STT as an important form of treatment for orthopaedic patients with various knee joint dysfunctions.

Lower extremity kinematic coupling during single and double leg landing and gait in female junior athletes with dynamic knee valgus

BACKGROUND

Dynamic knee valgus (DKV) is a common lower extremity movement disorder among females. This study aimed to investigate kinematic couplings between lower extremity joints in female junior athletes with DKV during single and double-leg landing and gait.

METHODS

Twenty-six physically active female junior athletes (10-14 years old) with DKV were recruited. Kinematic couplings between rearfoot, tibia, knee, and hip were extracted using eight Vicon motion capture cameras and two force plates. Zero-lag cross-correlation coefficient and vector coding were used to calculate kinematic couplings between joints during physical tasks. Paired t-test and Wilcoxon tests were run to find significant couplings between joint motions and coupling strengths. Bonferroni posthoc was used to determine significance with α ≤ 0.05.

RESULTS

The results showed that the strongest kinematic relationship existed between rearfoot eversion/inversion and tibial internal/external rotation during all three tasks. Correlations of the rearfoot supination/pronation with tibial rotations, knee, and hip motions in sagittal, frontal, and transverse planes were very strong to strong during double-leg landing and moderate to weak during gait. A weak correlation was observed between rearfoot supination/pronation and hip adduction/abduction during single-leg landing.

CONCLUSIONS

Coupling relationships between rearfoot, knee, and hip vary by the task intensity and alignment profiles in female juniors with DKV.

Closed chain dorsiflexion and the regional interdependence implications on fundamental movement patterns in collegiate athletes

PURPOSE

An association between limited ankle closed kinetic chain dorsiflexion range of motion (CKCDFROM) and movement dysfunction in the lower quarter is often implied, limited research exists linking CKCDFROM and gross movement patterns, such as the squatting. The purpose of this study is to investigate the association between CKCDFROM and movement patterns in collegiate athletes, as measured by the functional movement screen (FMS).

MATERIALS AND METHODS

A quasi-experimental observational analytical cohort study with 147 athletes from five Division III collegiate men's and women's athletic teams were included in the study. CKCDFROM was assessed utilizing the lunge test. Movement patterns, specifically the deep squat (DS) and inline lunge (ILL) were assessed utilizing the FMS qualitative criteria. Descriptive statistical analysis examined the association between CKCDFROM limitations and a dysfunctional deep squat or ILL.

RESULTS

Seventy-nine (53.7%) and 30 (20.4%) participants scored a "1" on their FMS deep squat test and ILL, respectively. Participants who scored a "1" on the deep squat and ILL were 3.75 times as likely (3.75 odds ratio; 95% CI 1.57-9.14; p = 0.002) and 1.53 times as likely (1.53 odds ratio; 95% CI 0.65-3.60; p = 0.392), respectively, to have at least one ankle CKCDFROM limitation. The deep squat (DS) was statistically significant, but the ILL did not rise to the level of significance.

DISCUSSION

Physical therapists should consider regional interdependence implications of movement dysfunction stemming from impairments within the kinetic chain.

CONCLUSION

A dysfunctional lower extremity movement pattern might be associated with a lack of CKCDFROM. Clinicians will likely benefit from assessing CKCDFROM in those exhibiting dysfunctional squatting and/or lunging.

Examining the Dynamic Nature of Anterior Cruciate Ligament Injury Risk Factors in Women's Collegiate Soccer

CONTEXT

Anterior cruciate ligament (ACL) injuries are a common and devastating injury in women's soccer. Several risk factors for ACL injury have been identified, but have not yet been examined as potentially dynamic risk factors, which may change throughout a collegiate soccer season.

DESIGN

Prospective cohort study.

METHODS

Nine common clinical screening assessments for ACL injury risk, consisting of range of motion, movement quality, and power, were assessed in 29 Division I collegiate women's soccer players. Preseason and midseason values were compared for significant differences. Change scores for each risk factor were also correlated with cumulative training loads during the first 10 weeks of a competitive soccer season.

RESULTS

Hip external rotation range of motion and power had statistically significant and meaningful differences at midseason compared with preseason, indicating they are dynamic risk factors. There were no significant associations between the observed risk factor changes and cumulative training load.

CONCLUSIONS

Hip external rotation range of motion and power are dynamic risk factors for ACL injury in women's collegiate soccer athletes. Serial screening of these risk factors may elucidate stronger associations with injury risk and improve prognostic accuracy of screening tools.

Applications of Pose Estimation in Human Health and Performance across the Lifespan

The emergence of pose estimation algorithms represents a potential paradigm shift in the study and assessment of human movement. Human pose estimation algorithms leverage advances in computer vision to track human movement automatically from simple videos recorded using common household devices with relatively low-cost cameras (e.g., smartphones, tablets, laptop computers). In our view, these technologies offer clear and exciting potential to make measurement of human movement substantially more accessible; for example, a clinician could perform a quantitative motor assessment directly in a patient's home, a researcher without access to expensive motion capture equipment could analyze movement kinematics using a smartphone video, and a coach could evaluate player performance with video recordings directly from the field. In this review, we combine expertise and perspectives from physical therapy, speech-language pathology, movement science, and engineering to provide insight into applications of pose estimation in human health and performance. We focus specifically on applications in areas of human development, performance optimization, injury prevention, and motor assessment of persons with neurologic damage or disease. We review relevant literature, share interdisciplinary viewpoints on future applications of these technologies to improve human health and performance, and discuss perceived limitations.

Joint Angle, Range of Motion, Force, and Moment Assessment: Responses of the Lower Limb to Ankle Plantarflexion and Dorsiflexion

There is limited research on the biomechanical assessment of the lower limb joints in relation to dynamic movements that occur at the hip, knee, and ankle joints when performing dorsiflexion (DF) and plantarflexion (PF) among males and females. This study investigated the differences in joint angles (including range of motion (ROM)) and forces (including moments) between the left and right limbs at the ankle, knee, and hip joints during dynamic DF and PF movements in both males and females. Using a general linear model employing multivariate analysis in relation to the joint angle, ROM, force, and moment datasets, the results revealed significant main effects for gender, sidedness, phases, and foot position with respect to joint angles. Weak correlations were observed between measured biomechanical variables. These results provide insightful information for clinicians and biomechanists that relate to lower limb exercise interventions and modelling efficacy standpoints.

Effects of gastrocnemius stretching with talus-stabilizing taping on ankle dorsiflexion and balance in individuals with limited ankle dorsiflexion: A randomized controlled trial

BACKGROUND: Various interventions have been recommended to increase ankle dorsiflexion range of motion (DFROM); however, few studies have investigated the long-term effects of applying gastrocnemius stretching with talus-stabilizing taping (GSTST). OBJECTIVE: To compare the effects of gastrocnemius stretching (GS) and GSTST on DFROM and balance in subjects with limited DFROM. METHODS: Twenty-six subjects with limited DFROM were randomly allocated to either the GS group (n= 13) or GSTST group (n= 13) for 6 weeks. Maximum DFROM before heel-off during gait, passive DFROM, posterior talar glide, flexibility of the gastrocnemius, and the lower-quarter Y-balance test (YBT-LQ) were assessed pre-intervention and post-intervention. Two-way repeated-measures analysis of variance was used to compare the changes in variables. RESULTS: The GSTST group had greater maximum DFROM before heel-off, passive DFROM, and posterior talar glide than the GS group. Gastrocnemius flexibility and YBT-LQ scores increased significantly post-intervention in both groups; however, there was no significant difference between the groups. CONCLUSIONS: GSTST is recommend for improving ankle DFROM and balance in subjects with limited DFROM.

ACL Return to Sport Testing: It's Time to Step up Our Game

Patients and physicians have long looked to physical therapists to help determine an athlete's readiness to return to sport (RTS) following anterior cruciate ligament reconstruction (ACLR). This is a complex decision that must take into account biological healing, joint stability, functional performance, and psychological readiness. Considering that the vast majority of medical professionals use time as the sole determinant of an athlete's readiness, and few are using performance-based criteria, it appears as though our profession is failing to capture the necessary information to make this weighty recommendation. The time is now to take a hard look at current practice patterns with RTS testing and push the envelope forward. The purpose of this clinical commentary is challenge our failing status quo by disseminating a robust model for RTS testing that incorporates temporal and criterion-based factors, as well as intrinsic and extrinsic data.

LEVEL OF EVIDENCE

5.

Can we predict the landing performance of simulated aerials in surfing?

This study explored which technical and physical attributes could predict superior and/or safe landing performance when surfers performed variations of a simulated aerial task. Fourteen surfers (age 20.6 ± 5.7 years, height 178.1 ± 9.50 cm, mass 70.6 ± 10.8 kg) had their lower limb mobility, squat jump, countermovement jump, and drop-and-stick landing performance assessed. Performance of two aerial variations (Frontside Air (FA) and Frontside Air Reverse (FAR)) was also measured, with variables relating to technical performance (critical feature and subjective ratings) and potential injury risk (relative total peak landing force and loading rates) collected. Multiple linear regressions were used to predict performance of both aerial variations based on a subset of independent variables. Four models could predict performance. Predicted technical capability in the FAR was mostly influenced by lead limb hip extension and lead limb knee flexion range of motion. Potential injury risk when surfers perform an FA and FAR was predicted to be mitigated by increasing lead ankle dorsiflexion range of motion, as well as trail hip extensor mobility to reduce the relative total peak force experienced when landing the FA. These simple outcome measures could be routinely assessed to ensure successful and safe aerial landings in surfing.

Parametric analysis of landing injury : The effect of landing posture and joint displacement

During landing, the lower limb joints work concertedly to reduce landing forces. Changing the biomechanics of one joint can alter landing strategies in other joints thus affecting the probability of injury. Therefore, understanding the mutual effects between the joints is crucial for the prevention of lower extremity injuries. The purpose of this study is to evaluate the effect of joint displacement and initial contact posture on the impact forces and joint kinematics during drop landing, via computational modeling. The impact dynamics of drop landing is modeled by a three link planar model. Different landing scenarios are then simulated to investigate how restricting the displacement of one joint and changing its initial contact angle affect the other joints' ranges of motion, the trunk motion, and the impact forces. Our study suggests that the impact force increases by up to [Formula: see text], [Formula: see text] and [Formula: see text], by restricting the hip, knee and ankle joints, respectively. Restricting each one of the hip and knee joints decreases the displacement of the other one. The association between the ankle displacement and the hip/knee motion depends on joints' stiffness and landing posture. Moreover, changing the landing posture affects the joints kinematics and impact forces significantly. A safe landing posture is a fore-foot landing with knee flexion angle of around 30° to 40° and a foot-ground angle of 40° to 55°, which decreases the impact force by more than [Formula: see text] in comparison to the erect posture with horizontal foot. The obtained results are of practical importance in training landing skills and designing force-reducing external components.

Ankle Dorsiflexion Affects Hip and Knee Biomechanics During Landing

BACKGROUND

Restricted ankle dorsiflexion range of motion (DFROM) has been linked to lower extremity biomechanics that place an athlete at higher risk for injury. Whether reduced DFROM during dynamic movements is due to restrictions in joint motion or underutilization of available ankle DFROM motion is unclear.

HYPOTHESIS

We hypothesized that both lesser total ankle DFROM and underutilization of available motion would lead to high-risk biomechanics (ie, greater knee abduction, reduced knee flexion).

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Nineteen active female athletes (age, 20.0 ± 1.3 years; height, 1.61 ± 0.06 m; mass, 67.0 ± 10.7 kg) participated. Maximal ankle DFROM (clinical measure of ankle DFROM [DF-CLIN]) was measured in a weightbearing position with the knee flexed. Lower extremity biomechanics were measured during a drop vertical jump with 3-dimensional motion and force plate analysis. The percent of available DFROM used during landing (DF-%USED) was calculated as the peak DFROM observed during landing divided by DF-CLIN. Univariate linear regressions were performed to identify whether DF-CLIN or DF-%USED predicted knee and hip biomechanics commonly associated with injury risk.

RESULTS

For every 1.0° less of DF-CLIN, there was a 1.0° decrease in hip flexion excursion (r² = 0.21, P = 0.05), 1.2° decrease in peak knee flexion angles (r² = 0.37, P = 0.01), 0.9° decrease in knee flexion excursion (r² = 0.40, P = 0.004), 0.002 N·m·N^-1·cm^-1 decrease in hip extensor work (r² = 0.28, P = 0.02), and 0.001 N·m·N^-1·cm^-1 decrease in knee extensor work (r² = 0.21, P = 0.05). For every 10% less of DF-%USED, there was a 3.2° increase in peak knee abduction angles (r² = 0.26, P = 0.03) and 0.01 N·m·N^-1·cm^-1 lesser knee extensor work (r² = 0.25, P = 0.03).

CONCLUSION

Lower levels of both ankle DFROM and DF-%USED are associated with biomechanics that are considered to be associated with a higher risk of sustaining injury.

CLINICAL RELEVANCE

While total ankle DFROM can predict some aberrant movement patterns, underutilization of available ankle DFROM can also lead to higher risk movement strategies. In addition to joint specific mobility training, clinicians should incorporate biomechanical interventions and technique feedback to promote the utilization of available motion.

Noncontact Knee Ligament Injury Prevention Screening in Netball: A Clinical Commentary with Clinical Practice Suggestions for Community-Level Players

Netball is a predominantly female team court-sport which is played worldwide. Netball is becoming more popular in the United States following its countrywide introduction to schools and community centers. A unique characteristic of netball is the footwork rule which restricts players to a one-step landing after catching the ball. Most netball landings are single-leg landings resulting in high vertical ground reaction forces and high skeletal tissue forces. Thus, high-risk landing events that have the biomechanical potential for injury occur frequently. Noncontact knee ligament injuries are common following a knee abduction collapse when landing. Because the consequences of noncontact knee ligament injury are profound, strategies are needed to mitigate the burden of such injury for players, teams, and society. The purpose of this clinical commentary is to demonstrate how theoretical principles, different types of research, and different levels of evidence underpin a rational clinical reasoning process for developing noncontact knee ligament injury prevention screening procedures in netball. The theoretical principles that are discussed in this commentary include injury control, the sequence of prevention, principles of screening in injury prevention, the multifactorial model of injury etiology, complex systems theory, and systems science. The different types of research that are reviewed include descriptive and analytic-observational studies. The different levels of evidence that are discussed include prospective studies, cross-sectional studies, and clinicians' own kinesiological modelling. Subsequently, an integrated approach to the evidence-informed development of noncontact knee ligament injury prevention screening procedures is presented. Clinical practice suggestions include a selection of evidence-informed screening tests that are quickly and easily implemented with netball players in local communities. The need for repeated screening at strategic timepoints across a season/year is explained. Sports physical therapists will find this commentary useful as an example for how to undertake clinical reasoning processes that justify the content of screening procedures contributing to noncontact knee ligament injury prevention in community-level netball.

LEVEL OF EVIDENCE

5.

The Effect of Tissue Flossing on Ankle Range of Motion, Jump, and Sprint Performance in Elite Rugby Union Athletes

CONTEXT

Given the relatively novel technique of tissue flossing is currently lacking in the research literature despite some positive findings in preliminary studies, the modality clearly requires further research. Current evidence suggests that band flossing results in performance improvements and may also be an effective method in injury prevention.

OBJECTIVE

Previous research has shown that tissue flossing may result in increased ankle range of motion, jump, and sprinting performance in recreational athletes. The present study aims to extend on this research, within an elite athlete sample.

DESIGN

Counterbalanced, cross-over design with experimental and control trials, separated by 1 week.

SETTING

University laboratory.

PARTICIPANTS

Fourteen professional male rugby union athletes (mean [SD]: age 23.9 [2.7] y).

INTERVENTION

Application of a floss band to both ankles (FLOSS) for 2 minutes or without flossing of the ankle joints (CON) on 2 separate occasions.

MAIN OUTCOME MEASURES

A weight-bearing lunge test, a countermovement jump test, and a 20-m sprint test at pre and at 5 and 30 minutes post application of the floss band or control.

RESULTS

There were no statistically significant interactions between treatment (FLOSS/CON) and time for any of the measured variables (P > .05). Effect size analysis revealed small benefits for FLOSS in comparison with CON for countermovement performance 5 minutes post (d = 0.28) and for 10-m (d = -0.45) and 15-m (d = -0.24) sprint time 30 minutes post.

CONCLUSION

Findings from the current study suggest minimal benefits of tissue flossing when applied to the ankle joint in elite athletes for up to 30 minutes following their application.

Increased Ankle Range of Motion Reduces Knee Loads During Landing in Healthy Adults

Decreased dorsiflexion range of motion (DROM) can be modified using static stretching and joint mobilizations and may attenuate known knee anterior cruciate ligament injury risk factors. It is not known how these interventions compare to each other and how they improve knee landing mechanics. This study's purpose was to determine the immediate effects of static stretching and joint mobilization interventions on DROM measurement changes and right-leg drop jump knee landing mechanics. Eighteen females and 7 males, all recreationally active, completed 2 study sessions. Active and passive DROM, the weight-bearing lunge test, the anterior reach portion of the Star Excursion Balance Test, and a right-leg drop jump landing task were completed before and after the intervention. Change in DROM (ΔDROM) was calculated for DROM assessments between preintervention and postintervention. Pairwise dependent t tests determined no differences in ΔDROM between interventions, and statistical parametric mapping determined increased knee flexion (P = .004) and decreased anterior shear force (P = .015) during landing after both interventions. Increased DROM improves sagittal plane displacement and loading at the knee. Stretching may be a more feasible option in a healthy population for those wanting to maintain range of motion and decrease knee injury risk without physical therapist involvement.

Ankle Instability Patients Exhibit Altered Muscle Activation of Lower Extremity and Ground Reaction Force during Landing: A Systematic Review and Meta-Analysis

This review aimed to investigate characteristics of muscle activation and ground reaction force (GRF) patterns in patients with ankle instability (AI). Relevant studies were sourced from PubMed, CINAHL, SPORTDiscus, and Web of Science through December 2019 for case-control study in any laboratory setting. Inclusion criteria for study selection were (1) subjects with chronic, functional, or mechanical instability or recurrent ankle sprains; (2) primary outcomes consisted of muscle activation of the lower extremity and GRF during landing; and (3) peer-reviewed articles with full text available, including mean, standard deviation, and sample size, to enable data reanalysis. We evaluated four variables related to landing task: (1) muscle activation of the lower extremity before landing, (2) muscle activation of the lower extremity during landing, (3) magnitude of GRF, and (4) time to peak GRF. The effect size using standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for these variables to make comparisons across studies. Patients with AI had a lower activation of peroneal muscles before landing (SMD = -0.63, p < 0.001, CI = -0.95 to -0.31), greater peak vertical GRF (SMD = 0.21, p = 0.03, CI = 0.01 to 0.40), and shorter time to peak vertical GRF (SMD = -0.51, p < 0.001, CI = -0.72 to -0.29) than those of normal subjects during landing. There was no significant difference in other muscle activation and GRF components between the patients with AI and normal subjects (p > 0.05). Altered muscle activation and GRF before and during landing in AI cases may contribute to both recurrent ankle and ACL injuries and degenerative change of articular.

Optimising the 'Mid-Stage' Training and Testing Process After ACL Reconstruction

Outcomes following anterior cruciate ligament (ACL) reconstruction need improving, with poor return-to-sport rates and high risk of secondary re-injury. There is a need to improve rehabilitation strategies after ACL reconstruction, if we can support enhanced patient outcomes. This paper discusses how to optimise the mid-stage rehabilitation process after ACL reconstruction. Mid-stage is a difficult and vitally important stage of the functional recovery process and provides the foundation on which to commence late-stage rehabilitation training. Often many aspects of mid-stage rehabilitation (e.g. knee extensors isolated muscle strength) are not actually restored prior to return-to-sport. In addition, if we are to allow time for optimal late-stage rehabilitation and return-to-sport training, we need to optimise the mid-stage rehabilitation approach and complete it in a timely manner. This paper forms a key part of a strategy to optimise the ACL rehabilitation approach and considers factors more specific to mid-stage rehabilitation characterised in 3 areas: (1) muscle strength: muscle and joint specific, in particular at the knee level, with the knee extensors and flexors and distally with the triceps surae and proximally with the lumbo-pelvic-hip complex, as well as closed kinetic chain strength; (2) altered basic motor patterning (movement quality) and (3) fitness re-conditioning. In addition, the paper provides recommendations on how to implement these into practice, discussing training planning and programming and suggests specific screening to monitor work and when the athlete is able to progress to the next stage (e.g. late-stage rehabilitation criteria).

The influence of kinesio taping on trunk and lower extremity motions during different landing tasks: implications for anterior cruciate ligament injury

Purpose

The purpose of the study was to investigate the influence of a 72-h KT application on trunk and lower extremity kinematics during different landing tasks.

Methods

Twenty-nine competitive male athletes participated in this study. The sum of knee valgus and lateral trunk lean, symmetry index (SI), and peak angles of lateral trunk lean, hip flexion, knee abduction and flexion were assessed for all participants during single-leg drop landing (SLDL), single-leg vertical drop jump (SLVDJ), vertical drop jump (DLVDJ), and double leg forward jump (DLFJ), at baseline and seventy-two hours following KT application.

Results

The KT application resulted in more knee flexion and abduction, sum of knee valgus and lateral trunk lean as compared with the non-KT condition during SLDL (P < 0.05). Nonetheless, there were no differences in SI, maximum angle of the lateral trunk lean during SLDL, SLVDJ, nor hip flexion, knee abduction, and flexion during DLVDJ, and DLFJ tasks (P > 0.05).

Conclusions

The research findings suggest that KT after 72-h application may improve knee abduction and sum of knee valgus and lateral trunk lean during SLDL, knee flexion during SLDL and SLVDJ in individuals displaying risky single-leg kinematics. Therefore, KT application may marginally improve high-risk landing kinematics in competitive male athletes.

Level of evidence

Level III.

The Dorsiflexion Range of Motion Screen: A Validation Study

BACKGROUND

Limited ankle dorsiflexion (DF) is associated with ankle sprains and other lower extremity injuries. Current ankle measurements can be laborious to perform in an athletic environment.

PURPOSE

The purpose of this study was to determine the reliability and discriminant validity of a novel closed-chain ankle DF ROM test, the standing ankle dorsiflexion screen (SADS).

STUDY DESIGN

Reliability and validity study.

METHODS

Thirty-seven healthy subjects participated in the study. Two raters measured closed-chain ankle DF range of motion (ROM) using a modified lunge position with an electronic inclinometer. Four raters measured ankle DF using the SADS. Reliability was calculated using intraclass correlation coefficients (ICC) and kappa coefficients for the raters using an electronic inclinometer and the SADS scale, respectively. An independent t-test compared the SADS categories of "behind" and "beyond" to the modified lunge test ROM (p<0.05).

RESULTS

Excellent ICC values (0.95 [95% CI (0.92,0.97)]) and high kappa values were observed (0.61-0.81), with high percent agreement (86-94%). There was a significant difference in ankle DF ROM between the nominally scored "behind" and "beyond" categories, regardless of rater or trial analyzed (behind: 41.3° ± 4.7°; beyond: 51.8°± SD 6.1°, p <0.001).

CONCLUSIONS

The SADS was observed to have excellent interrater reliability and high discriminant validity. Furthermore, there was a distinct closed chain ankle DF ROM difference between the "behind" and "beyond" SADS nominal scores.

CLINICAL RELEVANCE

The SADS can be used as a quick and efficient closed chain ankle DF ROM screen.

LEVEL OF EVIDENCE

2b.

Shorter work boot shaft height improves ankle range of motion and decreases the oxygen cost of work

Work boots featuring design elements implemented to protect the foot and lower limb are common in many industries. However, boot design can have negative unintended consequences such as increases in work related fatigue and injury risk. This study compared joint kinematics and the physiological cost of two commercially available steel-toed work boots with different shaft designs worn throughout a simulated work task. A boot with a lower-cut and scalloped shaft allowed greater sagittal plane range of motion at the ankle joint compared to a boot with a higher-cut straight shaft, particularly in the late stance phase of the gait cycle. This was coupled with a decreased physiological cost of treadmill walking (2.6 and 3.1% improvement in oxygen consumption and walking economy, respectively), likely caused by a more efficient gait pattern. A lower-cut and scalloped shaft could lead to decreases in work-related fatigue and the subsequent risk of injuries in workers. Practitioner summary: Gait kinematics and the physiological cost of work boots with different shaft heights has not previously been investigated. A randomised cross-over study design found that a boot with a lower shaft height and scalloped collar improved ankle range of motion and reduced the physiological cost experienced by the wearers. Abbreviations: ROM: range of motion; FS: full shaft; SS: scalloped shaft; COM: centre of mass; HR: heart rate; RPE: rating of perceived exertion; ES: effect size.

Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued

CONTEXT

Ankle dorsiflexion range of motion (DF ROM) has been associated with a number of kinematic and kinetic variables associated with landing performance that increase injury risk. However, whether exercise-induced fatigue exacerbates compensatory strategies has not yet been established.

OBJECTIVES

(1) Explore differences in landing performance between individuals with restricted and normal ankle DF ROM and (2) identify the effect of fatigue on compensations in landing strategies for individuals with restricted and normal ankle DF ROM.

DESIGN

Cross-sectional.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twelve recreational athletes with restricted ankle DF ROM (restricted group) and 12 recreational athletes with normal ankle DF ROM (normal group).

MAIN OUTCOME MEASURE(S)

The participants performed 5 bilateral drop-landings, before and following a fatiguing protocol. Normalized peak vertical ground reaction force, time to peak vertical ground reaction force, and loading rate were calculated, alongside sagittal plane initial contact angles, peak angles, and joint displacement for the ankle, knee, and hip. Frontal plane projection angles were also calculated.

RESULTS

At the baseline, the restricted group landed with significantly less knee flexion (P = .005, effect size [ES] = 1.27) at initial contact and reduced peak ankle dorsiflexion (P < .001, ES = 1.67), knee flexion (P < .001, ES = 2.18), and hip-flexion (P = .033, ES = 0.93) angles. Sagittal plane joint displacement was also significantly less for the restricted group for the ankle (P < .001, ES = 1.78), knee (P < .001, ES = 1.78), and hip (P = .028, ES = 0.96) joints.

CONCLUSIONS

These findings suggest that individuals with restricted ankle DF ROM should adopt different landing strategies than those with normal ankle DF ROM. This is exacerbated when fatigued, although the functional consequences of fatigue on landing mechanics in individuals with ankle DF ROM restriction are unclear.

Relationship Between Training Factors and Injuries in Stand-Up Paddleboarding Athletes

Stand-up paddleboarding (SUP) is an increasingly popular sport but, as in other sports, there is an injury ratio associated with practicing it. In other types of sport, some factors have been linked to the likelihood of suffering an injury, among which stretching, core training and resistance training may be considered the most significant. Therefore, the main aim of this study was to identify the training factors that could influence injuries suffered by participants in international SUP competitions. Ninety-seven questionnaires were collected from paddlers who participated in an international SUP circuit, with epidemiological data being gathered about injuries and different questions related to the training undertaken. A multi-factor ANOVA test was used to identify the factors which influence the state of injury. Results showed that almost 60% of injuries occurred in the arms or in the upper thoracic region, around 65% of which were in tendons or muscles and, in almost half of cases, were related to overuse. Likewise, the results showed that athletes with injury performed fewer resistance training sessions per week (p = 0.028), over fewer months per year (p = 0.001), more weekly training sessions (p = 0.004) and, lastly, a greater volume of weekly training (p = 0.003) than athletes without injury. Moreover, the most important training factors that reduce the likelihood of suffering an injury were taken into account-in. particular, resistance training alone (p = 0.011) or together with CORE training (p = 0.006) or stretching (p = 0.012), and the dominant side of paddling (p = 0.032). In conclusion, resistance training would seem to reduce the likelihood of injury among SUP practitioners, and such benefits could be obtained by resistance training alone or in combination with CORE training or stretching.

Reliability of isokinetic tests of velocity- and contraction intensity-dependent plantar flexor mechanical properties

"Flexibility" tests are traditionally performed voluntarily relaxed by rotating a joint slowly; however, functional activities are performed rapidly with voluntary/reflexive muscle activity. Here, we describe the reliabilities and differences in maximum ankle range of motion (ROM_max ) and plantar flexor mechanical properties at several velocities and levels of voluntary force from a new test protocol on a commercially available dynamometer. Fifteen participants had their ankle joint dorsiflexed at 5, 30, and 60° s^-1 in two conditions: voluntarily relaxed and while producing 40% and 60% of maximal eccentric torque. Commonly reported variables describing ROM_max and resistance to stretch were subsequently calculated from torque and angle data. Absolute (coefficient of variation (CV%) and typical error) and relative (ICC_2,1 ) reliabilities were determined across two testing days (≥72 h). ROM_max relative reliability was good in voluntarily relaxed tests at 30 and 60° s^-1 and moderate at 5° s^-1 , despite CVs ≤ 10% for all velocities. Tests performed with voluntary muscle activity were only reliable when performed at 5° s^-1 , and ROM_max reliability was moderate and CV ≤ 8%. For most variables, the rank order of participants differed between the slow-velocity, relaxed test, and those performed at faster speeds or with voluntary activation, indicating different information. A person's flexibility status during voluntarily relaxed fast or active stretches tended to differ from their status in the traditional voluntarily relaxed, slow-velocity test. Thus, "flexibility" tests should be completed under conditions of different stretch velocity and levels of muscle force production, and clinicians and researchers should consider the slightly larger between-day variability from slow-velocity voluntarily relaxed tests.

Association between ankle angle at initial contact and biomechanical ACL injury risk factors in male during self-selected single-leg landing

BACKGROUND

Increasing the ankle plantar-flexion angle at initial contact (IC) during landing reduces the impact features associated with landing, such as the vertical ground reaction force and loading rate, potentially affecting the risk of anterior cruciate ligament (ACL) injury. However, the relationships between the ankle plantar-flexion angle at IC and the previously identified biomechanical factors related to noncontact ACL injury have not been studied.

RESEARCH QUESTION

Thus, the purpose of this study was to determine whether significant relationships exist between the ankle plantar-flexion angle at IC and the biomechanical factors related to noncontact ACL injury.

METHODS

The peak anterior tibial shear force, peak external knee valgus moment, peak knee valgus angle, and combined peak external knee valgus plus tibial internal rotation moments were measured in 26 individuals while performing self-selected, single-leg landing. Pearson correlation analyses were performed to assess the relationships between the ankle plantar-flexion angle at IC and the biomechanical factors mentioned above.

RESULTS

The greater ankle plantar-flexion angle at IC was related to smaller the peak knee valgus moment (r = -0.5, p = 0.009) and the combined peak knee valgus plus internal rotation moments (r = -0.58, p = 0.001).

SIGNIFICANCE

These results suggest that large ankle plantar-flexion angle at IC might be associated with lesser loading of the knee frontal plane and altering the self-selective ankle angle may result in biomechanical changes associated with ACL injury risk.

Effect of Foot-Planting Strategy on Anterior Cruciate Ligament Loading in Women During a Direction Diversion Maneuver: A Musculoskeletal Modeling Approach

Background

Although there is a higher prevalence of noncontact anterior cruciate ligament (ACL) injuries during a direction diversion maneuver (DDM), no previous studies have reported how foot-planting strategies affect ACL loading.

Purpose

To investigate the effect of foot-planting strategies on ACL loading in women during a DDM task using a musculoskeletal modeling approach.

Study Design

Descriptive laboratory study.

Methods

A total of 13 female participants performed a DDM task, which involved running at 4.5 ± 0.2 m/s and turning left at 35° to 55° under a foot-planting strategy in 3 directions: neutral, toe-in, and toe-out. Kinematic and kinetic data were measured with the use of a 3-dimensional motion capture system and force platform to calculate variables such as joint angle, shear force, and moment. Anterior ACL and posterior ACL forces were extracted using musculoskeletal modeling.

Results

The peak anterior ACL force was significantly larger for the toe-out condition (31.29 ± 4.02 N/body weight [BW]) compared with the toe-in condition (25.43 ± 5.68 N/BW) (P = .047), with no significant difference in the neutral condition. The toe-out condition had a higher knee valgus angle (2.98° ± 4.20°; P = .041), knee shear force (10.20 ± 1.69 N/BW; P = .009), and knee internal rotation moment (-0.18 ± 0.16 N·m/BW×height; P = .012) than the toe-in and neutral conditions.

Conclusion

Through musculoskeletal modeling, we were able to conclude that the toe-out condition during the DDM might result in a higher risk of ACL injuries. Athletes and sports practitioners should avoid the toe-out foot-planting strategy when participating in a sporting activity.

Clinical Relevance

Based on these findings, medical professionals and athletic coaches can gain knowledge on how foot-planting strategy affects ACL loading. Understanding the actual cause of an ACL injury can be useful for designing preventive training programs or strategies to decrease the risk of such injuries.

Effects of Walking With Talus-Stabilizing Taping on Passive Range of Motion, Timed Up and Go, Temporal Parameters of Gait, and Fall Risk in Individuals With Chronic Stroke: A Cross-sectional Study

OBJECTIVE

The purpose of this study was to determine the effects of walking with talus-stabilizing taping on ankle dorsiflexion passive range of motion, the timed up-and-go test, temporal parameters of gait, and fall risk in individuals with chronic stroke.

METHODS

In this cross-sectional design study, 20 participants with chronic stroke (9 female, 11 male), aged 60.5 ± 8.1 years, were included. Three conditions were evaluated: barefoot, immediately after applying talus-stabilizing taping, and after 5 minutes of walking with talus-stabilizing taping. One-way repeated-measures analysis of variance was used to determine the differences in ankle dorsiflexion passive range of motion, timed up-and-go test results, temporal parameters of gait, and fall risk across the 3 conditions.

RESULTS

Ankle dorsiflexion passive range of motion, walking speed, and single-limb support phase were significantly improved after 5 minutes of walking with talus-stabilizing taping compared to those in the barefoot and immediately-after-taping conditions. The timed up-and-go test, double-limb support phase, and fall-risk results significantly decreased more after 5 minutes of walking with talus-stabilizing taping compared to barefoot and immediately after taping.

CONCLUSION

After the application of talus-stabilizing taping, ankle dorsiflexion passive range of motion, timed up-and-go test results, temporal parameters of gait, and fall risk were reduced in individuals with chronic stroke.

Restricting ankle dorsiflexion does not mitigate the benefits of external focus of attention on landing biomechanics in healthy females

PURPOSE

Restricted ankle dorsiflexion can promote aberrant biomechanics associated with risk for knee injury during dynamic activities. Attentionally focused instructions have been used to improve high-risk knee biomechanics during landing tasks. Yet, it is unknown whether attentionally focused instruction can effectively improve landing patterns in the presence of a mechanical restriction on the ankle. Therefore, our purpose was to determine whether restricting ankle dorsiflexion by use of bracing mitigated the effects of attentional foci on landing biomechanics in healthy females.

METHODS

We used a crossover design to investigate lower extremity biomechanics in 19 healthy females between the ages of 18-35 during a series of jump-landing tasks. Participants completed 6 blocks of 3 jump-landings on separate force platforms in a randomized order based on brace condition (brace, no brace) and mode of attentional foci (neutral, internal focus [IF], external focus [EF]). Attentionally focused instructions were provided immediately prior to 3 practice jump-landings, followed by 5 test jump-landings with self-controlled feedback only.

RESULTS

Ankle bracing decreased peak dorsiflexion and sagittal range of motion (ROM) (mean difference: 5.7-5.8°), and peak inversion and frontal ROM (mean difference: 2.4-3.0°). However, hip flexion ROM (mean difference: 1.8°) increased compared to the no brace condition. Regardless of ankle bracing, EF instruction increased peak hip flexion (mean difference: 4.9°) and hip flexion range of motion (mean difference: 3.8-4.6°), while decreasing peak knee valgus (mean difference: 0.8-1.0°) and knee valgus moment (mean difference: 0.04 Nm/kg). Additionally, EF instruction increased peak hip abduction to a similar degree when braced (mean difference: 3.6-4.0°) and not braced (mean difference: 2.1-2.5°). Lastly, EF instruction increased hip abduction ROM only when braced (mean difference: 2.3-2.4°), but decreased peak knee valgus power only when not braced (mean difference: 0.18 W/kg).

CONCLUSIONS

Our findings indicate that mechanically restricting ankle dorsiflexion does not mitigate the ability of EF instruction to enhance jump-landing performance by means of improving hip and knee biomechanics in healthy females. However, our findings suggest an improved ability to control the rate of knee valgus loading when not braced. Therefore, we conclude that EF instruction remains a viable clinical strategy to improve landing patterns in the presence of restricted ankle dorsiflexion, yet this approach may be ineffective to reduce the rate of knee joint loading.

Patellofemoral Joint Loading During Single-Leg Hopping Exercises

CONTEXT

Single-leg hopping is used to assess a dynamic knee stability. Patellofemoral pain is often experienced during these exercises, and different cadences of jumping are often used in rehabilitation for those with patellofemoral pain. No studies to date have examined patellofemoral joint loading during single-leg hopping exercise with different hopping cadences.

OBJECTIVE

To determine if single-leg hopping at 2 different cadences (50 and 100 hops per minute [HPM]) leads to a significant difference in patellofemoral joint loading variables.

SETTING

University research laboratory.

PARTICIPANTS

Twenty-five healthy college-aged females (age 22.3 [1.8] y, height 171.4 [6.3] cm, weight 67.4 [9.5] kg, Tegner Activity Scale 4.75 [1.75]) participated.

MAIN OUTCOME MEASURES

Three-dimensional kinematic and kinetic data were measured using a 15-camera motion capture system and force platform. Static optimization was used to calculate muscle forces and then used in a musculoskeletal model to determine patellofemoral joint stress (PFJS), patellofemoral joint reaction force (PFJRF), quadriceps force (QF), and PFJRF loading rate, during the first and last 50% of stance phase.

RESULTS

Greater maximal PFJRF occurred at 100 HPM, whereas greater PFJRF loading rate occurred at 50 HPM. However, overall peak QF and peak PFJS were not different between the 2 cadences. At 50 HPM, there was greater PFJS, PFJRF, peak PFJRF loading rate, and peak QF during the first 50% of stance when compared with the last 50%.

CONCLUSION

Training at 50 HPM may reduce PFJRF and PFJRF loading rate, but not PFJS or QF. Patellofemoral joint loading variables had significantly higher values during the first half of the stance phase at the 50 HPM cadence. This may be important with training individuals with patellofemoral pain.

Back foot influence on dorsiflexion using three different positions of the weight bearing lunge test

OBJECTIVES

To determine whether back foot (BF) position influences dorsiflexion range of motion (DFROM) during three different positions of the weight bearing lunge test (WBLT).

DESIGN

Randomised, repeated measures design.

SETTING

Sports clubs.

PARTICIPANTS

52 athletes participating in cutting and pivoting sports.

MAIN OUTCOME MEASURES

DFROM was obtained using a WBLT in three different BF positions: BF heel in full contact with the floor, BF heel raised off the floor and BF was non weight bearing (NWB). All measurements were obtained using three methods: inclinometer at the tibial tuberosity, toe to wall distance and goniometer angle from the lateral malleolus to the fibula head. Differences between testing positions were determined using a repeated measures one-way ANOVA and reliability analysis was performed using the Intraclass Correlation Coefficient (ICC).

RESULTS

DFROM was statistically significantly different for all three positions of the WBLT for each measurement technique (P < .001). These results were associated with large effect sizes for all BF positions and measurement techniques. Reliability ICC values were excellent for all measurements (ICC 0.94-0.99).

CONCLUSIONS

Results show that DFROM differs depending upon the position of the BF during the WBLT. Further research is needed to establish the reproducibility of these three BF positions due to the variability observed.

Application of a Floss Band at Differing Pressure Levels: Effects at the Ankle Joint

Galis, J and Cooper, DJ. Application of a floss band at differing pressure levels: Effects at the ankle joint. J Strength Cond Res XX(X): 000-000, 2020-The study aimed to examine the effects of different levels of pressure on ankle range of motion (ROM), strength, and power performance. A parallel-group design was used, and subjects were divided into 3 groups. After a warm-up and preintervention testing (ankle goniometry using a manual handheld goniometer and isokinetic dynamometry using a HUMAC NORM isokinetic dynamometer), subjects had underwrap (control) or a tissue flossing band, at 150 mm Hg (FLOSS150) or 200 mm Hg (FLOSS200) applied to one of their calves, followed by postintervention testing. Thirty university students participated and completed the testing in a university laboratory: dorsiflexion ROM (DFROM) and plantarflexion ROM (PFROM), peak torque, and power. A repeated-measures analysis of variance with Tukey post hoc showed no statistically significant differences (p > 0.05) preintervention to postintervention between each group, except for DFROM in FLOSS150 (p < 0.05). Medium and small effect sizes preintervention to postintervention were associated with improvements of DFROM (0.61; 95% confidence interval [CI] 0.39-0.83) and dorsiflexion power (0.29; 95% CI -0.13 to 0.72), respectively, in FLOSS150, while the effect size of PFROM preintervention to postintervention was -0.35 (95% CI -0.85 to 0.15) in FLOSS200. Tissue flossing of the ankle joint may be a useful intervention for increasing dorsiflexion ROM and power, which can be useful for injury prevention, enhancing performance and improving functional ability; however, the potentially harmful effects of the technique should be considered.

Efficacy of acupuncture versus sham acupuncture or waitlist control for patients with chronic plantar fasciitis: study protocol for a two-centre randomised controlled trial

INTRODUCTION

Plantar fasciitis (PF) is reported to be the most common cause of plantar heel pain. Acupuncture has been used for patients experiencing PF, but evidence of the efficacy of acupuncture on PF is limited. The primary objective of this trial is to compare combined acupuncture and sham acupuncture (SA) versus waitlist control for improving the level of pain experienced by patients suffering from chronic PF.

METHODS AND ANALYSIS

This will be a two-centre, parallel-group, sham and no-treatment controlled, assessor-blinded randomised trial. We will randomly allocate 120 participants with chronic PF to acupuncture, SA and waitlist control groups at a ratio of 2:1:1. Participants in the acupuncture and SA groups will receive a 30 min acupuncture or SA treatment for a total of 12 sessions over 4 weeks, with a 12-week follow-up. Participants in the waitlist control group will not undergo treatment for a period of 16 weeks but instead will have the option of 4 weeks (12 sessions) of acupuncture free of charge at the end of the follow-up period. The primary outcome will be the treatment response rate 4 weeks after randomisation, assessed as a minimum of 50% improvement in the worst pain intensity during the first steps in the morning compared with the baseline. All analyses will be performed with a two-sided p value of <0.05 considered significant following the intention-to-treat principle.

ETHICS AND DISSEMINATION

The study has been approved by the Ethical Committee of the Guang'anmen Hospital, China Academy of Chinese Medical Sciences (approval no. 2019-210-KY). The results will be disseminated through presentation at a peer-reviewed medical journal, the relevant conferences and scientific meetings.

TRIAL REGISTRATION

NCT04185259.

Effects of pelvic and core strength training on biomechanical risk factors for anterior cruciate ligament injuries

BACKGROUND

Little is known about the changes in biomechanical risk factors for an anterior cruciate ligament (ACL) injury after participation in a pelvic and core strength training (PCST) program in female team players.

METHODS

This is a randomized controlled trial for which a total of 29 female soccer players were recruited from a soccer club and split into two groups, namely, experimental group (EG, N.=18; mean [SD] age, 17.8 [2.0 years], weight 64.0 [6.6] kg and height 1.7 [0.0] m) and control group (control, N.=11; mean [SD] age, 16.2 [1.2] years, weight 61.6 [7.3] kg and height 1.7 [0.0] m). The EG participated in an in-season 8-week PCST program (twice/week). Participants in the CG performed their normal training without additional pelvic and core strengthening. Pre- and postintervention knee frontal plane projection angle (FPPA), hip, knee and ankle peak flexion angles and jump height were collected during bilateral and unilateral drop jumps.

RESULTS

PCST significantly reduced FPPA at dynamic landing, in both dominant (-7.1º) and non-dominant lower extremities (-8º). Further, this training significantly increased the peak hip (24.4º) and knee flexion angles (14.94º), but not the peak ankle dorsiflexion angle (P>0.05) which, significantly decreased in the CG (-3.5º). Following the intervention, EG significantly increased measures obtained for both bilateral (2.84 cm) and unilateral jumps (1.33 cm for the dominant leg and 1.22 cm for the non-dominant leg) (P<0.05), not so for CG (P<0.05).

CONCLUSIONS

PCST resulted in improvements on ACL injury risk factors and vertical drop jump performance, suggesting that strengthening this body part warrants not only injury prevention, but increases jumping performance.

Lower extremity range of motion and alignment: A reliability and concurrent validity study of goniometric and three-dimensional motion analysis measurement

Background

Knowing correlations between passive goniometric and dynamic three-dimensional motion analysis measurements of lower extremity range of motion and alignment would benefit knee injury risk assessment.

Purpose

To investigate reliability and concurrent validity of lower extremity assessment with goniometry and three-dimensional motion analysis.

Methods

Thirty-eight participants (76 limbs) were examined in standardized positions by two physiotherapists with simultaneous goniometric and three-dimensional motion analysis measurements of passive range of motion and alignment. Intra-class correlation coefficient (ICC) and median differences were calculated.

Results

Hip rotation reliability, ICC 0.74–0.89 and validity 0.74–0.94. Tibial rotation reliability, ICC 0.24–0.75 and validity 0.08–0.61. Knee extension reliability, ICC 0.44–0.73 and validity 0.22–0.60. Knee valgus/varus reliability, ICC 0.36–0.68 and validity 0.25–0.62. Tibial torsion reliability, ICC 0.52–0.77 and validity 0.58–0.81. Ankle dorsiflexion reliability, ICC 0.12–0.73 and validity 0.51–0.83. Median differences in reliability and validity ranged from -2.0° to 3.0° and from -6.6° to 7.5° respectively.

Conclusion

Goniometric and three-dimensional motion analysis methods define the lower body segments differently making some degree of discrepancy in the measurements inevitable. Nevertheless, the variables chosen in this study are all strongly associated with anterior cruciate ligament rupture and some may prove useful to identify individuals at risk of knee injury during sport activities.

Study design

Cross-sectional laboratory study.

Ground Reaction Forces Are Predicted with Functional and Clinical Tests in Healthy Collegiate Students

Increased vertical and posterior ground reaction forces (GRFs) are associated with anterior cruciate ligament (ACL) injury. If a practical means to predict these forces existed, ACL injury risk could be attenuated. Forty-two active college-age individuals (21 females, 20.66 ± 1.46 y, 70.70 ± 2.36 cm, 82.20 ± 7.60 kg; 21 males, 21.57 ± 1.28 y, 65.52 ± 1.87 cm, 64.19 ± 9.05 kg) participated in this controlled laboratory study. GRFs were ascertained by having the subjects perform a unilateral landing task onto a force plate. Several clinical measures (Fat Free Mass (FFM), dorsiflexion passive range of motion (DPROM), isometric peak force of the lateral hip rotators, knee flexor/extensor peak force ratio (H:Q), the completion of the overhead deep squat), two functional tests (Margaria–Kalamen, Single Leg Triple Hop (SLTH)), and sex served as the predictor variables. Regression models to predict the GRFs normalized to the FFM (nGRFz, nGRFy) were generated. nGRFz was best predicted with a linear regression equation that included SLTH and DPROM (adjusted R² = 0.274; p = 0.001). nGRFy was best predicted with a linear regression equation that included H:Q, FFM, and DPROM (adjusted R² = 0.476; p < 0.001). Simple clinical measures and functional tests explain a small to moderate amount of the variance associated with the FFM normalized vertical and posterior GRFs in active college-age individuals.

Improved Ankle Mobility After a 4-Week Training Program Affects Landing Mechanics: A Randomized Controlled Trial

Howe, LP, Bampouras, TM, North, JS, and Waldron, M. Improved ankle mobility after a 4-week training program affects landing mechanics: a randomized controlled trial. J Strength Cond Res XX(X): 000-000, 2020-This study examined the effects of a 4-week ankle mobility intervention on landing mechanics. Twenty subjects with restricted ankle dorsiflexion range of motion (DF ROM) were allocated to either a strength training only (n = 9) or a strength training and ankle mobility program (n = 11). Subjects performed a weight-bearing lunge test and bilateral drop-landings before and after the intervention. Normalized peak vertical ground reaction force (vGRF), time to peak vGRF, and loading rate were calculated, alongside sagittal-plane initial contact angles, peak angles, and sagittal-plane joint displacement for the ankle, knee, and hip. Frontal-plane projection angles were also calculated. After the intervention, only the strength and mobility group improved ankle DF ROM (mean difference = 4.1°, effect size [ES] = 1.00, p = 0.002). A one-way analysis of covariance found group effects for ankle joint angle at initial contact (p = 0.045), ankle (p < 0.001) and hip joint angle at peak flexion (p = 0.041), and sagittal-plane ankle (p < 0.001) and hip joint displacement (p = 0.024) during bilateral drop-landings. Post hoc analysis revealed that the strength and mobility group landed with greater ankle plantarflexion at initial contact (mean difference = 1.4 ± 2.0°, ES = 0.46) and ankle dorsiflexion at peak flexion (mean difference = 6.3 ± 2.9°, ES = 0.74) after the intervention, resulting in a greater ankle joint displacement (mean difference = 7.7 ± 4.0°, ES = 1.00). However, the strength training only group landed with increased peak hip flexion (mean difference = 14.4 ± 11.0°, ES = 0.70) and hip joint displacement (mean difference = 8.0 ± 6.6°, ES = 0.44) during post-testing. The findings suggest that changes in landing strategies following the performance of a strength training program are specific to whether restrictions in ankle mobility are considered as part of the intervention.

Ankle flossing alters periarticular stiffness and arterial blood flow in asymptomatic athletes

BACKGROUND

Tissue flossing has been introduced to increase impaired range of motion (ROM) and flexibility, to enhance prevention and rehabilitation, as well as to improve athletic performance; however, limited evidence exists for its efficacy. The aim of the present study was to evaluate the effects of ankle flossing on periarticular stiffness and perfusion via Acoustic Radiation Force Impulse (ARFI) elastography and Power Doppler Sonography (PDS).

METHODS

Twenty-one healthy students (age: 24±2 years, BMI: 22±3 kg/m²) were recruited as participants. ARFI was performed to evaluate periarticular ankle stiffness involving the anterior ankle capsule (AC), the anterior talofibular ligament (ATFL) and the peroneus brevis muscle (PBM). Arterial blood flow was assessed in the dorsal pedal artery. Measurements were taken under resting conditions (T<inf>0</inf>) and twice after standardized ankle flossing (T<inf>1</inf>: 0 min., T<inf>2</inf>: 60 min. postintervention).

RESULTS

The connective tissue stiffness decreased significantly after ankle flossing compared to baseline (T<inf>1</inf>, AC: -12%, P=0.009, ATFL: -12%, P=0.003; T<inf>2</inf>, AC: -8%, P=0.002, ATFL: -9%, P=0.015). The PBM stiffness decreased by 3% (T<inf>1</inf>, P=0.304) and 4% (T<inf>2</inf>, P=0.029). The perfusion measures significantly increased by 30% at T<inf>1</inf> compared to baseline (P=0.001); no significant changes were observed at T<inf>2</inf> (P=0.492).

CONCLUSIONS

This is the first study demonstrating decreased AC and ATFL stiffness and reactive hyperemia to be key mechanisms of ankle flossing. Additional studies must be conducted to determine whether changes in biomechanical properties influence dynamic ankle stability.

Bottom-Up Kinetic Chain in Drop Landing among University Athletes with Normal Dynamic Knee Valgus

The study investigated the influence of ankle strength and its range of motion (ROM) on knee kinematics during drop landing. Fifteen male and fifteen female university athletes with a normal range of dynamic knee valgus (DKV) (knee frontal plane projection angle: men = 3° to 8°, females = 7° to 13°) were recruited. They performed drop landing at height 30 cm and 45 cm with three-dimensional motion capture and analysis. Knee angles were compared at specific landing phases. Isokinetic ankle strength was tested at 60°/s angular velocity while the weight-bearing lunge test was conducted to evaluate ankle ROM. For males, strength for both plantarflexors and dorsiflexors were associated with knee kinematics at both heights (30 cm: r = −0.50, p = 0.03; 45 cm: r = −0.45, p = 0.05) during maximum vertical ground reaction force (MVGRF) phase. For females, ankle invertor strength and knee kinematics were associated at both 30cm (r = 0.53; p = 0.02,) and 45 cm landing heights (r = 0.49, p = 0.03), while plantarflexor strength and knee kinematics showed a significant association during initial contact (r = 0.70, p < 0.01) and MVGRF (r = 0.55, p = 0.02) phases at height 30 cm only. Male and female athletes with normal range of DKV showed a significant relationship between ankle strength and knee kinematics at specific landing phases. These relationships varied with increased landing height.

The relationship between the deep squat movement and the hip, knee and ankle range of motion and muscle strength

[Purpose] We examined and clarified the relationship between the maximum squat depth and the range of motion of the ankle, knee, and hip joints, and the knee and hip muscle strength. [Participants and Methods] Nine healthy males participated in this study and performed a deep squat with the upper extremities raised; the movement was analyzed by two-dimensional motion analysis. We measured the ankle dorsiflexion, hip flexion, and knee flexion ranges of motion, as well as the knee extension and hip flexion muscle strengths and analyzed the relationship between the squatting motion, the range of motion, and the muscle strength of each joint. [Results] The right ankle dorsiflexion range of motion was a significant predictor of the ankle dorsiflexion angle on both sides. The right knee flexion range of motion was a significant predictor of the knee flexion angle, and the left knee flexion range of motion was a significant predictor of the trunk anterior tilt angle on both sides. The right ankle dorsiflexion range of motion was a significant predictor of the right hip flexion angle and vice versa. [Conclusion] This study reveals that movement on one side affects contralateral movement, which is important when evaluating the deep squat motion as a functional test.