The influence of knee position on ankle dorsiflexion - a biometric study

Foot Posture and Ankle Dorsiflexion as Risk Factors for Developing Achilles Tendinopathy and Plantar Fasciitis: A Case-Control Study

BACKGROUND

Plantar fasciitis (PF) and Achilles tendinopathy (AT) are common injuries that primarily affect people engaged in sport or occupational weightbearing activities. Identifying modifiable risk factors is important for the treatment and prevention of these injuries. The purpose of this study was to evaluate whether foot posture or ankle dorsiflexion are risk factors for developing AT or PF, and if there were any differences between PF and AT patients.

METHODS

This was a case-control study of 108 patients with PF and 114 patients with AT, compared to the same number of referred patients in 2 control groups never having had these injuries, matched for sex, age, body mass index (BMI), sport, and occupational weightbearing activities. Included patients were 20-65 years with ultrasonographic-verified PF or midsubstance AT. Foot posture was assessed using Foot Posture Index (FPI) classifying the feet into 3 categories: FPI 0-5 normal foot, 6-12 hyperpronated, <0 hypopronated. Ankle dorsiflexion was measured with a goniometer in weightbearing with straight and bent knee.

RESULTS

Abnormal foot posture was associated with an increased risk for sustaining both AT (odds ratio [OR] 3.4-4.1) and PF (OR 3.2-3.8). Hyperpronation being the major reason for this association with ORs 5.4-5.5 compared with hypopronation with ORs 2.6-2.9. However, decreased dorsiflexion was not a risk factor: instead, there was an increased ankle dorsiflexion in patients with AT or PF compared with their control groups. Comparison between PF and AT patients demonstrated that PF affected mostly women, and AT mostly men, PF patients were 2.4 years (CI 0.2-4.5) younger, and had 25% more occupational weightbearing than AT patients. However, no differences in BMI or weightbearing physical activity was demonstrated.

CONCLUSION

Hypopronation and hyperpronation but not limited ankle dorsiflexion was associated with increased risk for AT or PF.

Combining specific task-oriented training with manual therapy to improve balance and mobility in patients after stroke: a mixed methods pilot randomised controlled trial

PURPOSE

In absence of existing studies, to describe changes in balance and mobility, following specific task-oriented training (TOT), its combination with talocrural manual therapy (MT-TOT) or no intervention, in chronic stroke patients. To explore the feasibility of a full-scale randomised controlled trial (RCT) based on criteria of recruitment, retention and adherence rates, adverse events, falls and acceptability of the intervention.

MATERIALS AND METHODS

Using an assessor-blinded pilot RCT, 36 stroke patients were allocated to either MT-TOT, TOT, or controls. Supervised interventions were performed 45 min, 2×/weekly, for 4 weeks, and home-based practice 20 min, 4x/weekly for 4 weeks. Qualitative interviews evaluated intervention acceptability. Outcomes of balance, mobility, ankle dorsiflexion range of motion (ROM), falls and health-related quality of life (HRQoL) were assessed at baseline, post-intervention and 4-week follow-up.

RESULTS

Preliminary efficacy of MT-TOT and TOT was shown in improving balance (effect size 0.714), walking speed (0.683), mobility (0.265), dual-tasking mobility (0.595), falls (0.037), active and passive talocrural ROM (0.603; 0.751) and activities and social participation related HRQoL domains (0.332-0.784) in stroke patients. The feasibility of a larger RCT was confirmed.

CONCLUSIONS

Specific MT-TOT and TOT appeared effective and are feasible in stroke patients. A larger RCT is needed to validate the results.Trial Registration: German Clinical Trials Register, DRKS00023068. Registered on 21.09.2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023068.

Are floating toes associated with lifestyle in children? A cross-sectional study

BACKGROUND

Floating toes are a condition and deformity in which some of the toes are afloat. Many functional impairments in floating toes have been previously studied lately and several factors related to floating toes have also been reported. However, no reports have considered the relationship between lifestyle and floating toes among children. The purpose of this study was to reveal the prevalence of floating toes among school children and reveal its relationship with lifestyle.

METHODS

In total, 138 young male baseball players were recruited. Lifestyle was evaluated by using a questionnaire and chosen whether the main lifestyle was Japanese or Western, if the bedding was futons or beds, and if the toilet was Japanese style (a squat toilet) or Western style. Floating toes were defined as toes that were not in contact with the mat. Ankle dorsiflexion in the knee-flexed and knee-extended positions was measured in a weight-bearing position. The relationship between the floating toes and lifestyles, and the comparison of ankle dorsiflexion range of motion between the lifestyles were statistically analyzed.

RESULTS

Players living in a Western style showed a significantly higher prevalence of floating toes on both feet compared with the players living in a Japanese style (throwing side; 39% vs. 19%, p = 0.04, and non-throwing side; 43% vs. 19%, p = 0.01). Players living in a Western style with beds showed a significantly smaller range of motion on both sides of ankle dorsiflexion in the knee-flexed position compared with those who were not (throwing side; 37.2 ± 5.7° vs. 39.0 ± 6.6°, p = 0.04, and non-throwing side; 36.8 ± 5.8° vs. 38.6 ± 6.1°, p = 0.04).

CONCLUSION

Children mainly living in a Western lifestyle showed a significantly higher prevalence of floating toes on both feet compared to those mainly living in a Japanese lifestyle. The prevalence of floating toes may be related to lifestyles among children.

TRIAL REGISTRATION

The study was approved by the institutional review board of the Waseda University Graduate School of Sport Sciences (IRB number 2021-185).

Noninvasive magnetic resonance-guided focused ultrasound for tendon disruption: an in vivo Animal study

PURPOSE

Surgical resection of the tendon is an effective treatment for severe contracture. Magnetic Resonance-guided Focused Ultrasound (MRgFUS) is a non-invasive ultrasonic therapy which produces a focal increase in temperature, subsequent tissue ablation and disruption. We evaluated MRgFUS as a clinically translatable treatment modality to non-invasively disrupt in vivo porcine tendons.

MATERIAL AND METHODS

In vivo Achilles tendons (n = 28) from 15-20kg Yorkshire pigs (n = 16) were randomly assigned to 4 treatment groups of 600, 900, 1200 and 1500 J. Pretreatment range of motion (ROM) of the ankle joint was measured with the animal under general anesthesia. Following MRgFUS treatment, success of tendon rupture, ROM increase, temperature, thermal dosage, skin burn, and histology analyses were performed.

RESULTS

Rupture success was found to be 29%, 86%, 100% and 100% for treatment energies of 600, 900, 1200 and 1500 J respectfully. ROM difference at 90° flexion showed a statistically significant change in ROM between 900 J and 1200 J from 16° to 27°. There was no statistical significance between other groups, but there was an increase in ROM as more energy was delivered in the treatment. For each of the respective treatment groups, the maximal temperatures were 58.4 °C, 63.3 °C, 67.6 °C, and 69.9 °C. The average areas of thermal dose measured were 24.3mm2, 53.2mm2, 77.8mm2 and 91.6mm2. The average areas of skin necrosis were 5.4mm2, 21.8mm2, 37.2mm2, and 91.4mm2. Histologic analysis confirmed tissue ablation and structural collagen fiber disruption.

CONCLUSIONS

This study demonstrated that MRgFUS is able to disrupt porcine tendons in vivo without skin incisions.

Analysis of electrical stimulation and voluntary muscle contraction on skeletal muscle oxygen uptake and mitochondrial recovery using near-infrared spectroscopy

PURPOSE

This investigation was to compare differences in skeletal muscle oxygen consumption ([Formula: see text]) and mitochondrial recovery between voluntary (VOL) and electrically stimulated (ES) plantarflexion contractions.

METHODS

Twelve men and women (26 ± 4.0 years; 171.8 ± 5.1 cm; 74.0 ± 13.7 kg) were seated in a chair with their right knee fully extended and right foot secured to a force transducer. ES electrodes and a near-infrared spectroscopy device were placed on the gastrocnemius. Participants performed ES plantarflexion contractions across a range of stimulation intensities at frequencies of 1 and 2 Hz and similar VOL contractions. Cuff occlusion occurred immediately following each series of contractions to measure [Formula: see text]. A standardized mitochondrial function assessment protocol was also performed to calculate K-constants between work-matched ES and VOL contractions.

RESULTS

For mitochondrial assessments, there were no significant differences between ES and VOL rate constants (2.03 ± 0.98 vs. 1.25 ± 1.35 min-1, p = 0.266). ES resulted in a significantly greater workrate-[Formula: see text] slope at 1 Hz (0.007 ± 0.007 vs. 0.001 ± 0.002% [Formula: see text]/s/N, p = 0.014) and 2 Hz (0.010 ± 0.010 vs. 0.001 ± 0.001% [Formula: see text]/s/N, p = 0.012), as well as a significantly greater workrate-[Formula: see text] Y-intercept at 2 Hz (1.603 ± 1.513 vs. 0.556 ± 0.564% [Formula: see text]/s, p = 0.035) but not 1 Hz (0.579 ± 0.448 vs. 0.442 ± 0.357% mV̇O2/s, p = 0.535) when compared to VOL.

CONCLUSION

ES results in a significantly greater [Formula: see text] at similar work rates compared to VOL, however, the mitochondrial recovery rate constants were similar. The greater mVO2 with ES may partially contribute to the increased rate of fatigue during ES exercise in individuals with muscle paralysis.

Intra and interrater reliability for lower limb flexibility assessment using photogrammetry

INTRODUCTION

Photogrammetry represents an advancement in the flexibility evaluation, and although it was highly explored for postural assessment, there is a scarcity of studies analyzing lower limb angular measurements using it. The purpose of this study is to verify the reliability of intrarater and interrarater photogrammetry in assessing lower limb flexibility.

METHODS

This was a randomized cross-sectional observational study with test-retest design and a two-day interval. Thirty healthy, physically active adults were included. Three novice raters assessed the participants through flexibility tests of iliopsoas, hamstring, quadriceps and gastrocnemius on two occasions, and independently analyzed the captured images to establish reliability. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated.

RESULTS

Intrarater reliability was excellent for iliopsoas (ICC = 0.96; SEM = 1.4; MDC = 3.8), hamstring (ICC = 0.99; SEM = 1.1; MDC = 3.1), quadriceps (ICC = 0.99; SEM = 0.8; MDC = 2.3) and gastrocnemius (ICC = 0.98; SEM = 0.9; MDC = 2.5). Interrater reliability was excellent for iliopsoas (ICC = 0.94; SEM = 1.7; MDC = 4.6) and gastrocnemius (ICC = 0.91; SEM = 2.1; MDC = 5.8), but good for hamstring (ICC = 0.90; SEM = 2.8; MDC = 7.9) and quadriceps (ICC = 0.85; SEM = 3.0; MDC = 8.3).

CONCLUSIONS

The excellent intrarater and good to excellent interrater reliability suggest that photogrammetry assessment of lower limb flexibility by novice raters is reliable. However, clinicians should consider the higher threshold of range of motion change necessary to outweigh measurement error due to interrater variability.

Countermovement Jump Performance Is Related to Ankle Flexibility and Knee Extensors Torque in Female Adolescent Volleyball Athletes

Ankle flexibility and isokinetic knee torque/power generating capacity were previously suggested to contribute or to be correlated to the vertical countermovement jump (CMJ) performance. The aim of this study was to investigate the effect of the passive ankle joint dorsi flexion (θ_PDF) and the knee muscle's isokinetic torque and power on the CMJ in adolescent female volleyball players. The θ_PDF at a knee extension angle of 140 degrees were measured for 37 female post-pubertal volleyball players. Then, the players were assigned to either the flexible (n = 10) or inflexible (n = 14) groups according to earlier recommended criteria. Testing included the CMJ with and without an arm swing, and maximal knee extensions and flexions in 3 angular velocities on an isokinetic dynamometer. CMJ height performed with or without an arm swing (r₍₂₂₎ = 0.563, p = 0.040 and r₍₂₂₎ = 0.518, p = 0.009, respectively) and relative power (r₍₂₂₎ = 0.517, p = 0.010 and r₍₂₂₎ = 0.446, p = 0.030, respectively) were positively correlated with the extensors' torque at 180°/s and were negatively correlated with the flexibility level of the dominant side ankle (r₍₂₂₎ = -0.529, p = 0.008 and r₍₂₂₎ = -0.576, p = 0.030, respectively). A moderate positive correlation was also revealed between the CMJ height with and without an arm swing and the power of the non-dominant knee extensors (r₍₂₂₎ = 0.458, p = 0.024 and r₍₂₂₎ = 0.402, p = 0.049, respectively) and flexors (r₍₂₂₎ = 0.484, p = 0.016 and r₍₂₂₎ = 0.477, p = 0.018, respectively). Results of the 2 × 2 repeated ANOVA measurements revealed that flexible players jumped significantly (p < 0.05) higher during the CMJs, whilst there was a group effect only on the isokinetic knee extensor muscles' torque. In conclusion, a more flexible ankle joint and a higher isokinetic knee extensor's torque generating capacity resulted in higher CMJ performance. Therefore, ankle flexibility should be emphasized in training and is suggested to be included in preseason screening tests of youth female volleyball players.

Intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading: Implications for Achilles tendinopathy

Mechanical overload is considered the main cause of Achilles tendinopathy. In addition to tensile loads, it is believed that the Achilles tendon may also be exposed to compressive loads. However, data on intratendinous pressures are lacking, and consequently, their role in the pathophysiology of tendinopathy is still under debate. Therefore, we aimed to evaluate the intratendinous pressure changes in the Achilles tendon during stretching and eccentric loading. Twelve pairs of human cadaveric legs were mounted in a testing rig, and a miniature pressure catheter was placed through ultrasound-guided insertion in four different regions of the Achilles tendon: the insertion (superficial and deep layers), mid-portion, and proximal portion. Intratendinous pressure was measured during three simulated loading conditions: a bent-knee calf stretch, a straight-knee calf stretch, and an eccentric heel-drop. It was found that the intratendinous pressure increased exponentially in both the insertion and mid-portion regions of the Achilles tendon during each loading condition (p < 0.001). The highest pressures were consistently found in the deep insertion region (p < 0.001) and during the eccentric heel-drop (p < 0.001). Pressures in the mid-portion were also significantly higher than in the proximal portion (p < 0.001). These observations offer novel insights and support a role for compression in the pathophysiology of Achilles tendinopathy by demonstrating high intratendinous pressures at regions where Achilles tendinopathy typically occurs. To what extent managing intratendinous pressure might be successful in patients with Achilles tendinopathy by, for example, avoiding excessive stretching, modifying exercise therapy, and offering heel lifts requires further investigation.

The effect of gastrocnemius resection on knee flexion in a total knee arthroplasty model

INTRODUCTION

Flexion contracture in knee arthritis and total knee arthroplasty (TKA) is a common and significant problem. An improvement in knee extension in patients with TKA and mild flexion contractures has been observed clinically when a gastrocnemius recession was performed for other concomitant conditions. The goal of this study was to quantify the effect of gastrocnemius recession on knee flexion in TKA cadaver model.

MATERIALS AND METHODS

Range of motion (ROM) of 23 cadaveric knees was determined with a navigation system before and after performing TKA using a medial parapetallar approach and after performing a gastrocnemius recession. Varus-valgus, flexion-extension, and internal-external rotation angles of the knee joint were recorded with leg in full extension and in 90°of knee flexion. Extension and flexion gaps were measured using a gap tensioning device. Dorsiflexion of the foot was measured with a goniometer when a torque moment of 10 Nm was applied to the ankle joint.

RESULTS

A statistically significant improvement of 5° in knee extension was observed following gastrocnemius recession (P = 0.015). Varus and valgus angles, internal, and external rotation were unaffected by gastrocnemius recession. Ankle dorsiflexion increased by 9° following gastrocnemius recession (P ≤ 0.001).

CONCLUSIONS

Performing a gastrocnemius recession improves the knee extension in TKA knees with flexion contractures. Gastrocnemius recession may be a useful technique to improve terminal extension in TKA.

Foundational Principles and Adaptation of the Healthy and Pathological Achilles Tendon in Response to Resistance Exercise: A Narrative Review and Clinical Implications

Therapeutic exercise is widely considered a first line fundamental treatment option for managing tendinopathies. As the Achilles tendon is critical for locomotion, chronic Achilles tendinopathy can have a substantial impact on an individual's ability to work and on their participation in physical activity or sport and overall quality of life. The recalcitrant nature of Achilles tendinopathy coupled with substantial variation in clinician-prescribed therapeutic exercises may contribute to suboptimal outcomes. Further, loading the Achilles tendon with sufficiently high loads to elicit positive tendon adaptation (and therefore promote symptom alleviation) is challenging, and few works have explored tissue loading optimization for individuals with tendinopathy. The mechanism of therapeutic benefit that exercise therapy exerts on Achilles tendinopathy is also a subject of ongoing debate. Resultingly, many factors that may contribute to an optimal therapeutic exercise protocol for Achilles tendinopathy are not well described. The aim of this narrative review is to explore the principles of tendon remodeling under resistance-based exercise in both healthy and pathologic tissues, and to review the biomechanical principles of Achilles tendon loading mechanics which may impact an optimized therapeutic exercise prescription for Achilles tendinopathy.

The effect of two different stretching exercises on the muscle tendon unit and range of motion

BACKGROUND: Stretching is commonly used for clinical and sports reason but the effects vary on time and the technique used. PURPOSE: To determine the acute effects of static and dynamic stretching of gastrocnemius muscle on muscle-tendon unit (MTU) and dorsiflexion range of motion (ROM) in the same individuals; to find out how long the stretching effects endure. METHODS: Twenty-eight males (mean age: 22.18 ± 2.58 years) were included in the study. A 45-s static stretching (SS) exercise was applied to the right leg 5 times and dynamic stretching (DS) of same duration to the other leg. Change in MTU was assessed by ultrasonography and active and passive ROM was measured with goniometer. All evaluations were performed before, immediately following, 5-min, 15-min and 30-min after stretching. RESULTS: Muscle thickness and pennation angle did not change over time with either techniques (p> 0.05). A significant muscle-tendon junction (MTJ) displacement occurred after the techniques (p< 0.05); the highest change was achieved after DS (p< 0.05). Both techniques improved active ROM values similarly (p< 0.05), but only dynamic stretching increased passive ROM significantly (p< 0.05). Active and passive ROM and MTJ displacement values at 30th – min were still higher than the baseline ones on the DS side (p< 0.05). However, SS increased active ROM angle immediately after application but this increment declined until the final measurement. CONCLUSION: We recommend using the dynamic stretching technique to achieve greater and longer lasting increases in tendon length and range of motion.

Relationship of Vertical Jump Performance and Ankle Joint Range of Motion: Effect of Knee Joint Angle and Handedness in Young Adult Handball Players

The purpose of the study is to examine the effect of the ankle joint range of motion (ROM) on the vertical jump (VJ) performance of adult handball players. The active (ACT) and passive (PAS) ankle joint ROM of 12 male members of the U21 National Handball Team with the knee joint at 0°, 40°, and 90° flexion (0° = fully extended knee) was evaluated using a video analysis measuring method. Participants also performed maximum VJ with (CMJ) and without (SQJ) countermovement, as well as with (AS) and without (NAS) an arm swing. Statistical analyses included 2 × 2 × 3 MANOVA, 2 × 2 repeated measures ANOVA, and Pearson’s correlation. Results reveal that PAS-ROM was larger (p < 0.05) in all knee joint flexion angles. ROM was smaller (p < 0.05) by approximately 10° at 0° compared to 90° knee flexion. No lateral effects on ROM due to the handedness of the players were observed. AS and CM resulted in increased jump height (p < 0.05). Finally, ACT-ROM when the knee joint was flexed at 40° was highly correlated (r ≥ 0.66, p < 0.05) with VJ performance except for CMJ-AS. In conclusion, the differences in the bi-articular gastrocnemius muscle flexibility due to the alteration of the angular position of the examined joints affected the ability to generate impulse during the VJ tests.

Reliability of ultrasonographic measurement of muscle architecture of the gastrocnemius medialis and gastrocnemius lateralis

Ultrasonography is widely used to measure gastrocnemius muscle architecture; however, it is unclear if values obtained from digitised images are sensitive enough to track architectural responses to clinical interventions. The purpose of this study was to explore the reliability and determine the minimal detectable change (MDC) of gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle architecture using ultrasound in a clinical setting. A trained sonographer obtained three B-mode images from each of the GM and GL muscles in 87 volunteers (44 males, 43 females; 22±9 years of age) on two separate occasions. Three independent investigators received training, then digitised the images to determine intra-rater, inter-rater, and test-retest reliability for fascicle length (FL), pennation angle (θ) and muscle thickness. Median FL, θ, and muscle thickness for GM and GL were 53.6–55.7 mm and 65.8–69.3 mm, 18.7–19.5° and 11.9–12.5°, and 12.8–13.2 mm and 15.9–16.9 mm, respectively. Intra- and inter-rater reliability of manual digitisation was excellent for all parameters. Test-retest reliability was moderate to excellent with intraclass correlation coefficient (ICC) values ≥0.80 for FL, ≥0.61 for θ, and ≥0.81 for muscle thickness, in both GM and GL. The respective MDC for GM and GL FL, θ, and muscle thickness was ≤12.1 mm and ≤18.00 mm, ≤6.4° and ≤4.2°, and ≤3.2 mm and ≤3.1 mm. Although reliable, the relatively large MDC suggest that clinically derived ultrasound measurements of muscle architecture in GM and GL are more likely to be useful to detect differences between populations than to detect changes in muscle architecture following interventions.

Feasibility of a specific task-oriented training versus its combination with manual therapy on balance and mobility in people post stroke at the chronic stage: study protocol for a pilot randomised controlled trial

Background

Large studies have shown that stroke is among the most relevant causes of acquired adult disability. Walking and balance impairment in stroke survivors often contribute to a restriction in daily activities and social participation. Task-oriented training (TOT) is an effective treatment strategy and manual therapy (MT) is used successfully to enhance ankle joint flexibility in this population. No study, however, has compared TOT against its combination with MT in a randomised controlled trial. Aims of this pilot study are therefore to explore the feasibility of a full-scale RCT using predefined feasibility criteria. Secondary aims are to explore the preliminary effects of specific TOT with a combined specific TOT-MT versus a control group in people post stroke.

Methods

This is a protocol of a 4-week prospective randomised controlled parallel pilot trial in people post stroke at the chronic stage with limited upper ankle joint mobility and an impairment in balance and mobility. At a German outpatient therapy centre using 1:1:1 allocation, 36 patients will be randomised into one of three groups: 15-min talocrural joint MT plus 30-min specific TOT (group A), 45-min specific TOT (group B), and controls (group C). Training will be goal-oriented including tasks that are based on daily activities and increased in difficulty utilising predefined progression criteria based on patients’ skill levels. Interventions will be provided face-to-face 2 times per week, for 4 weeks, in addition to 20-min concurrent x4 weekly home-based training sessions. Data will be collected by blinded assessors at baseline, post-intervention and 4-week follow-up. The primary outcome will be feasibility assessed by recruitment, retention and adherence rates, compliance, adverse events, falls and the acceptability of the intervention. Secondary outcomes will be walking speed, single and dual tasking functional mobility, ankle range of motion, disability and health-related quality of life.

Discussion

Feasibility provided, results from this study will be used to calculate the sample size of a larger randomised controlled trial to investigate the effects of specific TOT and specific TOT-MT compared to a post stroke control group.

Trial registration

German Clinical Trials Register, DRKS00023068. Registered on 21.09.2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023068.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00886-0.

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.

Exercise intervention protocol in children and young adults with cerebral palsy: the effects of strength, flexibility and gait training on physical performance, neuromuscular mechanisms and cardiometabolic risk factors (EXECP)

Background

Individuals with cerebral palsy (CP) have problems in everyday tasks such as walking and climbing stairs due to a combination of neuromuscular impairments such as spasticity, muscle weakness, reduced joint flexibility and poor coordination. Development of evidence-based interventions are in pivotal role in the development of better targeted rehabilitation of CP, and thus in maintaining their motor function and wellbeing. Our aim is to investigate the efficacy of an individually tailored, multifaceted exercise intervention (EXECP) in children and young adults with CP. EXECP is composed of strength, flexibility and gait training. Furthermore, this study aims to verify the short-term retention of the adaptations three months after the end of the EXECP intervention.

Methods

Twenty-four children and young adults with spastic CP will be recruited to participate in a 9-month research project with a 3-month training intervention, consisting of two to three 90-min sessions per week. In each session, strength training for the lower limbs and trunk muscles, flexibility training for the lower limbs and inclined treadmill gait training will be performed. We will evaluate muscle strength, joint flexibility, neuromuscular and cardiometabolic parameters. A nonconcurrent multiple baseline design with two pre-tests and two post-tests all interspaced by three months is used. In addition to the CP participants, 24 typically developing age and sex-matched participants will perform the two pre-tests (i.e. no intervention) to provide normative data.

Discussion

This study has a comprehensive approach examining longitudinal effects of wide variety of variables ranging from physical activity and gross motor function to sensorimotor functions of the brain and neuromuscular and cardiometabolic parameters, providing novel information about the adaptation mechanisms in cerebral palsy. To the best of our knowledge, this is the first intervention study providing supervised combined strength, flexibility and gait training for young individuals with CP.

Trial registration number

ISRCTN69044459, prospectively registered (21/04/2017).

Human Lower Limb Joint Biomechanics in Daily Life Activities: A Literature Based Requirement Analysis for Anthropomorphic Robot Design

Daily human activity is characterized by a broad variety of movement tasks. This work summarizes the sagittal hip, knee, and ankle joint biomechanics for a broad range of daily movements, based on previously published literature, to identify requirements for robotic design. Maximum joint power, moment, angular velocity, and angular acceleration, as well as the movement-related range of motion and the mean absolute power were extracted, compared, and analyzed for essential and sportive movement tasks. We found that the full human range of motion is required to mimic human like performance and versatility. In general, sportive movements were found to exhibit the highest joint requirements in angular velocity, angular acceleration, moment, power, and mean absolute power. However, at the hip, essential movements, such as recovery, had comparable or even higher requirements. Further, we found that the moment and power demands were generally higher in stance, while the angular velocity and angular acceleration were mostly higher or equal in swing compared to stance for locomotion tasks. The extracted requirements provide a novel comprehensive overview that can help with the dimensioning of actuators enabling tailored assistance or rehabilitation for wearable lower limb robots, and to achieve essential, sportive or augmented performances that exceed natural human capabilities with humanoid robots.

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.

Gastrocnemius tightness: A population based observational study

BACKGROUND

Gastrocnemius tightness is believed to be associated with multiple musculoskeletal pathologies such as back pain, plantar fasciitis and metatarsalgia. Although surgical treatment of gastrocnemius tightness is gaining popularity the objective definition of a gastrocnemius contracture has not been determined. The aim of our study was therefore to quantify gastrocnemius tightness in a normal population.

METHODS

Adult participants with no obvious foot and ankle pathology were recruited. Gastrocnemius tightness was quantified using a weightbearing lunge test. Maximal ankle-foot dorsiflexion was measured on participants with the knee in full extension and flexed to 20° using a digital inclinometer. The ankle-foot dorsiflexion index or ADI (difference in ankle dorsiflexion with the knee extended and flexed) was calculated. The ADI values were plotted on a histogram to identify the distribution of values and were compared according to participant demographics.

RESULTS

800 limbs from 400 participants were examined. There was a wide distribution of absolute values of maximal ankle-foot dorsiflexion ranging from 8 to 52°. The ADI ranged from 0 to19° and approximated to a normal distribution. The mean ADI was 6.04±3.49° and was positively correlated with age (r=0.132, P<0.001) and negatively correlated with physical activity (r=-0.88, P=0.015).

CONCLUSION(S)

Our study is the first to quantify gastrocnemius tightness in a large healthy adult population with differences observed by age and physical activity. We have defined an easy and reproducible weightbearing test that can be used in both research and clinical settings. The majority of the population have some degree of gastrocnemius tightness and values of ADI greater than 13° (>2 SD of the mean), as measured by the lunge test, may be considered abnormal.

Prevalence and classification of equinus foot in bilateral spastic cerebral palsy

BACKGROUND

Equinus is a common deformity in children with bilateral spastic cerebral palsy (BSCP). While dynamic equinus usually is treated by conservative therapy, fixed contractures need surgical correction. To choose the appropriate surgical method, it is important to discriminate between isolated gastrocnemius shortening and combined gastrosoleus complex contracture.

METHODS

In a retrospective study 938 patients with BSCP were studied. Patients underwent gait analysis and clinical examination. 248 patients (496 limbs) met the inclusion criteria. Data from motion analysis and clinical examination were used to calculate the prevalence and to further classify fixed equinus foot.

RESULTS

The prevalence of equinus was 83.3%. During clinical exam 246 (59.6%) limbs showed combined gastrosoleus complex contracture and 167 (40.4%) isolated gastrocnemius contracture. Max. DF at stance and mean DF at initial contact were significantly reduced in combined contracture, while max. ROM was increased (P < 0.05).

CONCLUSIONS

Corroborating the results of previous studies, in this study there was a high prevalence of fixed equinus in patients with BSCP. The prevalence of equinus correlated with increasing age. As half of the patients with fixed equinus show a different involvement of gastrocnemius and soleus muscle, we recommend to apply Silfverskiöld's test to discriminate between those two types to choose the appropriate surgical therapy.

The effects of alignment of an articulated ankle-foot orthosis on lower limb joint kinematics and kinetics during gait in individuals post-stroke

Mechanical tuning of an ankle-foot orthosis (AFO) is important in improving gait in individuals post-stroke. Alignment and resistance are two factors that are tunable in articulated AFOs. The aim of this study was to investigate the effects of changing AFO ankle alignment on lower limb joint kinematics and kinetics with constant dorsiflexion and plantarflexion resistance in individuals post-stroke. Gait analysis was performed on 10 individuals post-stroke under four distinct alignment conditions using an articulated AFO with an ankle joint whose alignment is adjustable in the sagittal plane. Kinematic and kinetic data of lower limb joints were recorded using a Vicon 3-dimensional motion capture system and Bertec split-belt instrumented treadmill. The incremental changes in the alignment of the articulated AFO toward dorsiflexion angles significantly affected ankle and knee joint angles and knee joint moments while walking in individuals post-stroke. No significant differences were found in the hip joint parameters. The alignment of the articulated AFO was suggested to play an important role in improving knee joint kinematics and kinetics in stance through improvement of ankle joint kinematics while walking in individuals post-stroke. Future studies should investigate long-term effects of AFO alignment on gait in the community in individuals post-stroke.

Validation of a weight bearing ankle equinus value in older adults with diabetes

Background

Accurate measurement of ankle joint dorsiflexion is clinically important as a restriction has been linked to many foot and ankle pathologies, as well as increased ulcer risk and delayed ulcer healing in people with diabetes. Use of the reliable weight bearing (WB) Lunge test is limited as normal and restricted ranges for WB ankle joint dorsiflexion are not identified. Additionally the extent of WB dorsiflexion restriction that results in clinically adverse outcomes is unclear. Therefore the aim of this investigation is to validate a proposed weight bearing equinus value (dorsiflexion < 30°) in unimpaired cohorts, and secondly to investigate any clinical effects this degree of ankle dorsiflexion restriction has on forefoot plantar pressure variables in older adults with diabetes.

Methods

Ankle dorsiflexion was measured using a Lunge test with the knee extended in young adults without diabetes (YA) and older adults with diabetes (DA). In-shoe and barefoot plantar pressure was recorded for the DA group. Spearman’s correlation was calculated to determine any association between the presence of ankle equinus and plantar pressure variables in the DA group. DA group differences in people with and without an equinus were examined.

Results

A weight bearing equinus of < 30°, assessed in a lunge using an inclinometer placed on the anterior tibia, falls within the restricted range in young unimpaired cohorts. In the DA group this degree of ankle restriction had a fair and significant association with elevated barefoot forefoot peak pressure (r = 0.274, p = 0.005) and pressure-time integrals (r = 0.321, p = .001). The DA equinus group had significantly higher barefoot peak pressure (mean kPa (SD): 787.1 (246.7) vs 652.0 (304.5), p = 0.025) and pressure-time integrals (mean kPa (SD): 97.8 (41.6) vs 80.4 (30.5), p = 0.017) than the DA non equinus group.

Conclusions

We support a preliminary weight bearing ankle equinus value of < 30°. This value represents a restricted range in young adults and is correlated with increased forefoot plantar pressure variables in older adults with diabetes. Mean population weight bearing ankle dorsiflexion data presented here for older adults with diabetes, will allow use of the more functional Lunge test with knee extended in research and clinical practice.

The effects of an articulated ankle-foot orthosis with resistance-adjustable joints on lower limb joint kinematics and kinetics during gait in individuals post-stroke

BACKGROUND

Resistance is a key mechanical property of an ankle-foot orthosis that affects gait in individuals post-stroke. Triple Action® joints allow independent adjustment of plantarflexion resistance and dorsiflexion resistance of an ankle-foot orthosis. Therefore, the aim of this study was to investigate the effects of incremental changes in dorsiflexion and plantarflexion resistance of an articulated ankle-foot orthosis with the Triple Action joints on lower limb joint kinematics and kinetics in individuals post-stroke during gait.

METHODS

Gait analysis was performed on 10 individuals who were post-stroke under eight resistance settings (four plantarflexion and four dorsiflexion resistances) using the articulated ankle-foot orthosis. Kinematic and kinetic data of the lower limb joints were recorded while walking using a three-dimensional Vicon motion capture system and a Bertec split-belt instrumented treadmill.

FINDINGS

Repeated measures analysis of variance revealed that adjustment of plantarflexion resistance had significant main effects on the ankle (P < 0.001) and knee (P < 0.05) angles at initial contact, while dorsiflexion resistance had significant (P < 0.01) main effects on the peak dorsiflexion angle in stance. Plantarflexion and dorsiflexion resistance adjustments appeared to affect the peak knee flexor moment in stance, but no significant main effects were revealed (P = 0.10). Adjustment of plantarflexion resistance also demonstrated significant (P < 0.05) main effects in the peak ankle positive power in stance.

INTERPRETATION

This study demonstrated that the adjustments of resistance in the ankle-foot orthosis with the Triple Action joints influenced ankle and knee kinematics in individuals post-stroke. Further work is necessary to investigate the long-term effects of the articulated ankle-foot orthoses on their gait.

Inter-rater reliability and validity of angle measurements using smartphone applications for weight-bearing ankle dorsiflexion range of motion measurements

OBJECTIVES

The purpose of this study was to examine the inter-rater reliability, validity, and error of angle measurements for ankle dorsiflexion range of motion while in the weight-bearing position using a smartphone application.

DESIGN

Reliability and validity study.

SETTING

Measurement positions were performed by one experienced examiner.

PARTICIPANTS

Eighteen volunteers participated in the study. Three examiners (examiner 1 and examiner 2 had completed the course to become qualified certified athletic trainers and examiner 3 did not belong to the course) performed smartphone application measurements.

MAIN OUTCOME MEASURES

Ankle dorsiflexion range of motion was measured in the lunge position. Radiographic measurements were performed using a bony landmark. The markerless method for application measurements was used, using a body part as a landmark.

RESULTS

Using the markerless method for application measurements, the intra-class correlation coefficients were 0.945. Using Pearson's correlation coefficient and intra-class correlation coefficients to compare the radiographic measurements and markerless method for application measurements, three examiners showed very high correlation (r > 0.9) and almost perfect (>0.81) intra-class correlation coefficient. Error values were less than 5° according to examiner 1 and examiner 2.

CONCLUSION

Smartphone application measurements using the markerless method of ankle dorsiflexion range of motion exhibited inter-rater reliability and high validity.

Prevalence of isolated gastrocnemius tightness in patients with foot and ankle pathology

Aims

Gastrocnemius tightness predisposes to musculoskeletal pathology and may require surgical treatment. However, it is not clear what proportion of patients with foot and ankle pathology have clinically significant gastrocnemius tightness. The aim of this study was to compare the prevalence and degree of gastrocnemius tightness in a control group of patients with a group of patients with foot and ankle pathology.

Patients and Methods

This prospective, case-matched, observational study compared gastrocnemius tightness, as assessed by the lunge test, in a control group and a group with foot and ankle pathology. Gastrocnemius tightness was calculated as the difference in dorsiflexion of the ankle with the knee extended and flexed.

Results

A total of 291 controls were paired with 97 patients with foot and ankle pathology (FAP). The mean gastrocnemius tightness was 6.0° (sd 3.5) in controls and 8.0° (sd 5.7) in the FAP group (p < 0.001). Subgroup analysis showed a mean gastrocnemius tightness of 10.3° (sd 6.0) in patients with forefoot pathology versus 6.9° (sd 5.3) in patients with other pathology (p = 0.008). A total of 12 patients (37.5%) with forefoot pathology had gastrocnemius tightness of > two standard deviations of the control group (> 13°).

Conclusion

Gastrocnemius tightness of > 13° may be considered abnormal. Most patients with foot and ankle pathology do not have abnormal degrees of gastrocnemius tightness compared with controls, but it is present in over a third of patients with forefoot pathology. Cite this article: Bone Joint J 2018;100-B:945–52.

Gastrocnemius Contracture in Patients With Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis is a chronic disease affecting multiple joints of the body. More than 90% of patients affected by rheumatoid arthritis develop foot or ankle pain over the course of their disease. The purpose of the current study was to report ankle dorsiflexion in rheumatoid arthritis patients as well as a control group utilizing a validated measurement instrument.

METHODS

Using a previously validated device, 70 patients presenting with rheumatoid arthritis and 70 controls were measured for ankle range motion and isolated gastrocnemius contractures. Clinical and goniometer measurement of ankle range of motion was also performed.

RESULTS

The rheumatoid arthritis group had a mean dorsiflexion of 12.3 degrees compared to a mean of 17.3 degrees in the control group ( P < .05). The difference in dorsiflexion was significantly less utilizing a goniometer than using the validated device, which may be due to measurement technique and external landmarks ( P < .05).

CONCLUSION

Patients with rheumatoid arthritis had less ankle dorsiflexion than the control group. The clinical significance of this study is that it provides evidence that patients with rheumatoid arthritis have decreased ankle dorsiflexion even despite a lack of foot and ankle pain. In light of the high lifetime incidence of foot and ankle pain in these patients, this study provides some evidence that the decreased ankle dorsiflexion may be a contributing factor in foot and ankle pain, but further studies are needed.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Intra-examiner reliability of measurements of ankle range of motion using a modified inclinometer: a pilot study

A modified inclinometer was designed for measuring total ankle range of motion (ROM) in the standing position for a large future study. The purpose of this pilot study was to assess the intra-examiner reliability of this new device in order to see if the examiner would be able to produce equally reliable measurements with this instrument as with a routinely used goniometer. Nineteen young healthy individuals took part in the pilot. The same examiner took the ROM measurements using both devices twice on the same day and one further time 2 or 3 days later. Test-retest reliability was measured using the intraclass correlation coefficient (ICC). The ICC values were 0.86 (95% CI=[0.67; 0.94]) and 0.83 (95% CI=[0.61; 0.93]) for the measurements taken with the goniometer on the same day and for those on two different days. The corresponding values for the modified inclinometer were 0.88 (95% CI=[0.72;0.95]) and 0.81 (95% CI=[0.57; 0.92]). Both instruments were found to have very good test-retest reliability.

Skeletal muscle water T2 as a biomarker of disease status and exercise effects in patients with Duchenne muscular dystrophy

The purpose of this study was to examine exercise effects on muscle water T₂ in patients with Duchenne muscular dystrophy (DMD). In 12 DMD subjects and 19 controls, lower leg muscle fat (%) was measured by Dixon and muscle water T₂ and R₂ (1/T₂) by the tri-exponential model. Muscle water R₂ was measured again at 3 hours after an ankle dorsiflexion exercise. The muscle fat fraction was higher in DMD participants than in controls (p < .001) except in the tibialis posterior muscle. Muscle water T₂ was measured independent of the degree of fatty degeneration in DMD muscle. At baseline, muscle water T₂ was higher in all but the extensor digitorum longus muscles of DMD participants than controls (p < .001). DMD participants had a lower muscle torque (p < .001) and exerted less power (p < .01) during exercise than controls. Nevertheless, muscle water R₂ decreased (T₂ increased) after exercise from baseline in DMD subjects and controls with greater changes in the target muscles of the exercise than in ankle plantarflexor muscles. Skeletal muscle water T₂ is a sensitive biomarker of the disease status in DMD and of the exercise response in DMD patients and controls.

Gastrocnemius Contracture in Patients With and Without Foot Pathology

BACKGROUND

Several studies report performing a recession of the gastrocnemius tendon as surgical treatment of foot and ankle pain related to an isolated gastrocnemius contracture. Few report ankle range of motion using a validated measurement device or report a control group. All previous studies reporting measurements using a validated device have been small in number.

METHODS

Using a previously validated device, 66 patients presenting with foot or ankle pain and 66 controls were measured for ankle range of motion and isolated gastrocnemius contractures. Clinical and goniometer measurement of ankle range of motion was also performed.

RESULTS

The foot and ankle pain group had a mean dorsiflexion of 11.6 degrees compared with a mean of 17.2 degrees in the control group (P < .0001). No patients in either group had less than 15 degrees of motion with the knee flexed. The difference in dorsiflexion was less using a goniometer than using the validated device, which may be due to measurement technique and external landmarks.

CONCLUSION

Patients with foot and ankle pain had less ankle dorsiflexion than the control group. This is the largest study to date using a validated measurement device as well as a control group and supports the findings of previous authors.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Ankle dorsiflexion: what is normal? Development of a decision pathway for diagnosing impaired ankle dorsiflexion and M. gastrocnemius tightness

INTRODUCTION

Impaired ankle dorsiflexion (ADF) is known to increase forefoot pressure, which is associated to various pathologies affecting the foot and ankle. M. gastrocnemius tightness (MGT) is its most common cause. Up to date we are missing a standardized examination procedure, norm values, and a valid decision pathway to diagnose impaired ADF and MGT. The aim of this study was to define norm values for ADF using a standardized examination procedure. These were used to define a decision pathway to diagnose impaired ADF and MGT.

MATERIALS AND METHODS

64 young, asymptomatic subjects were examined. Based on a standardized examination procedure, bilateral ADF, both with the knee extended and flexed, non-weight bearing and weight bearing, was assessed by three investigators. Inter-rater test reliability and norm values for ADF were calculated. Side differences were analyzed. ADF differences between the knee extended and flexed were calculated.

RESULTS

The standardized examination procedure revealed high ICC values (0.876-0.915). ADF values with the knee extended for the left/right limb were 22.7° ± 5.9° [95 % CI 21.2°-24.3°]/23.4° ± 6.5° [95 % CI 21.7°-25.1°] non-weight bearing and 33.3° ± 5.5° [95 % CI 31.9°-34.7°]/33.6° ± 5.6° [95 % CI 32.1°-35.0°] weight bearing. Physiological side differences with the knee extended were <6° (95 % CI). Knee flexion resulted in an approximate ADF increase of 10°.

CONCLUSIONS

Based on an extensive systematic approach, physiological values for ADF were assessed in a large asymptomatic population. This allowed the definition of a decision pathway to diagnose impaired ADF and MGT. Patients presenting with pathologies associated with impaired ADF should be examined according to the herein presented examination protocol. This systematic approach provides a consistent definition of impaired ADF and MGT, which is the prerequisite to study the effectiveness of treatment strategies for MGT.

Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination

Common foot and ankle pathologies have been linked to isolated Musculus gastrocnemius tightness (MGT). Various examination techniques have been described to assess MGT. Still, a standardized examination procedure is missing. Literature argues for weightbearing examination but the degree of knee flexion needed to eliminate the restraining effect of the M. gastrocnemius on ankle dorsiflexion (ADF) is unknown. This manuscript investigates the effect of knee flexion on ankle dorsiflexion and provides a detailed description of a standardized examination protocol. Examination on 20 healthy individuals revealed, that 20° of knee flexion is sufficient to fully eliminate the influence of the M. gastrocnemius on ADF. This builds the prerequisite for a standardized examination for MGT. Non-weightbearing and weightbearing examination of ADF has to be conducted with the knee fully extended and at least 20° flexed. Two investigators should conduct non-weightbearing testing with the subject in supine position. In order to obtain reliable results, the axis of the fibula should be marked. One examiner can conduct weightbearing examination with the subject in lunge stance. Isolated MGT is present if ADF is impaired with the knee fully extended and knee flexion results in a significant ADF increase. The herein presented standardized examination is the prerequisite for future studies aiming at establishing norm values.

Validity and Reliability of the Achillometer(®): An Ankle Dorsiflexion Measurement Device

Limited ankle dorsiflexion is closely related to important foot and ankle pathologies. Various measurement devices and methods have been examined, but these have demonstrated limited validity and reliability. The purpose of the present study was to assess the validity and intra- and interobserver reliability of the Achillometer(®). A total of 22 consecutive subjects with ankle or foot pathologies and 39 healthy participants were included. All participants were measured using the goniometer and the Achillometer(®), a portable device used to assess ankle dorsiflexion in the weightbearing position with knee in extension. The intraclass correlation coefficient, standard error of the mean, and minimal detectable change were determined. The goniometer and Achillometer(®) revealed high intraobserver reliability coefficients with an intraclass correlation coefficient of 0.88 (standard error of the mean 1.49, minimal detectable change 4.12) and 0.85 (standard error of the mean 1.57, minimal detectable change 4.34), respectively. The interobserver reliability of both measurement techniques ranged from 0.63 to 0.67. The Achillometer(®) showed a strong correlation with the goniometer for both observers. In conclusion, the Achillometer(®) is a valid measurement device to assess ankle dorsiflexion range of motion in the weightbearing position with an extended knee in a heterogeneous population. The device has good intraobserver and moderate interobserver reliability and measurement properties comparable to those of the goniometer.

Increased treatment durations lead to greater improvements in non-weight bearing dorsiflexion range of motion for asymptomatic individuals immediately following an anteroposterior grade IV mobilisation of the talus

Manual therapy aims to minimise pain and restore joint mobility and function. Joint mobilisations are integral to these techniques, with anteroposterior (AP) talocrural joint mobilisations purported to increase dorsiflexion range of motion (DF-ROM). This study aimed to determine whether different treatment durations of single grade IV anteroposterior talocrural joint mobilisations elicit statistically significant differences in DF-ROM. Sixteen asymptomatic male football players (age = 27.1 ± 5.3 years) participated in the study. Non-weight bearing (NWB) and weight bearing (WB) DF-ROM was measured before and after 4 randomised treatment conditions: control treatment, 30 s, 1 min, 2 min. NWB DF-ROM was measured using a universal goniometer, and WB DF-ROM using the weight-bearing lunge test. A within-subjects design was employed so that all participants received each of the treatment conditions. A 4 × 4 balanced Latin square design and 1 week interval between sessions reduced any residual effects. Two-way repeated measures ANOVA revealed a significant improvement in DF-ROM following all AP mobilisation treatments (p < 0.001). The within subjects contrasts showed that increases in treatment duration was associated with statistically significant improvements in DF-ROM (NWB DF-ROM control = 0.01%, 30 s = 14.2%, 1 min = 21.6%, 2 min = 32.8%; WB DF-ROM control = 0.01%, 30 s = 5.0%, 1 min = 7.6%, 2 min = 10.9%; p < 0.05). However, WB DF-ROM improvements were below the minimal detectable change scores needed to conclude that improvements were not a consequence of measurement error. This research shows that single session mobilisations can elicit NWB DF-ROM improvements in asymptomatic individuals in the absence of pain, whilst increases in treatment duration confer greater improvements in NWB DF-ROM within this population.