Effects of passive ankle dorsiflexion stiffness on ankle mechanics during drop landings

ObjectivesVertical landing tasks strain the Achilles tendon and plantar-flexors, increasing acute and overuse strain injury risk. This study aimed to determine how passive ankle dorsiflexion stiffness affected ankle mechanics during single limb drop landings at different vertical descent velocities.DesignCross-sectional study.MethodsPassive ankle dorsiflexion stiffness and passive weight-bearing dorsiflexion range of motion (DROM) were quantified for 42 men. Participants were then grouped as having low (LPS: 0.94 ± 0.15 Nm °^?1; n = 16) or high (HPS: 2.05 ± 0.36 Nm °^?1; n = 16; p < 0.001) passive ankle dorsiflexion stiffness. Three-dimensional ankle joint kinematics was quantified while participants performed drop landings onto a force platform at two vertical descent velocities (slow: 2.25 ± 0.16 m s^?1; fast: 3.21 ± 0.17 m s^?1).ResultsAlthough affected by landing velocity, there were no significant effects of passive ankle dorsiflexion stiffness, nor any significant ankle dorsiflexion stiffness × vertical descent velocity interactions on any outcome variables characterising ankle mechanics during drop landings. Furthermore, there was no significant difference between the groups for passive weight-bearing DROM (LPS: 43.9 ± 4.1°; HPS: 42.5 ± 5.7°), indicating that the results were not confounded by between-group differences in ankle range of motion.ConclusionsNeither high nor low passive ankle dorsiflexion stiffness was found to influence ankle biomechanics during drop landings at different descent velocities. Landing strategies were moderated more by the demands of the task than by passive ankle dorsiflexion stiffness, indicating that passive ankle dorsiflexion stiffness may not affect plantar-flexor strain during a drop landing.     

The influence of Mulligan ankle taping during balance performance in subjects with unilateral chronic ankle instability

Objective: To determine whether Mulligan ankle tape influenced the performance in subjects with unilateral chronic ankle instability (CAI) during static balance; postural sway recovery patterns after hopping and dynamic tracking balance tasks.Design: A cross-sectional, within-subjects experimental study design between 4 ankle conditions (taped; untaped: injured and uninjured).Participants: 20 volunteer recreational athletes with unilateral CAI were recruited. Means and standard deviations highlighted the athletes' characteristics: age = 23 ± 1 years; height = 173.1 ± 2.4 cm; weight = 69.3±3 kg; Functional Ankle Disability Index (FADI) = 93.5 ± 5.1% and FADI Sport = 84.2 ± 9.4%.Interventions: Mulligan ankle taping.Main Outcome Measurements: Static balance (10 s); postural sway recovery patterns after a 30 s functional hop test (immediately, 30 and 60 s); dynamic tracking balance tasks (wandering, target overshoot and reaction-time).Results: Between the four conditions, static balance showed no significant differences (p = 0.792); significant changes occurred in postural sway over time (p < 0.001); no significant changes were reported for the dynamic tracking tasks. Wandering was highly correlated with reaction-time and overshooting (p < 0.01).Conclusion: Under resting and fatigued conditions, Mulligan ankle taping did not impact on the neuromuscular control during static and dynamic balance in subjects with healthy and unstable ankles.     

Dorsiflexion deficit during jogging with chronic ankle instability

The purpose of the study was to determine whether individuals with chronic ankle instability (CAI) demonstrate altered dorsiflexion/plantar flexion range of motion (ROM) compared to controls during jogging. The case control study took place in a university motion analysis laboratory. Fourteen volunteers participated in the study, seven suffered from CAI (age 25 ± 4.2 years, height 173 ± 9.4 cm, mass 71 ± 8.1 kg) and seven were healthy, matched controls (age 25 ± 4.5 years, height 168 ± 5.9 cm, mass 67 ± 9.8 kg). All subjects jogged on an instrumented treadmill while a ten-camera motion analysis system collected three-dimensional kinematics of the lower extremities. The main outcome measure was sagittal plane (dorsiflexion/plantar flexion) range of motion of the ankle throughout the gait cycle. CAI subjects had significantly less dorsiflexion compared to the control group from 9% to 25% during jogging (4.83 ± 0.55°). CAI subjects demonstrated limited ankle dorsiflexion ROM during the time of maximal dorsiflexion during jogging. Limited dorsiflexion ROM during gait among individuals with CAI may be a risk factor for recurrent ankle sprains. These deficits should be treated appropriately by rehabilitation clinicians.     

Sector analysis of 125I permanent prostate brachytherapy provides a rapid and effective method of evaluating and comparing pre- and post-implant dosimetry

PurposeTo evaluate a sector analysis program in the assessment and comparison of pre- and post-implant dosimetric parameters during the development of an ¹²⁵I permanent prostate brachytherapy service.Methods and MaterialsA total of 50 consecutive men being treated with permanent prostate brachytherapy had dose–volume analysis in 12 sectors of their pre-implant ultrasound (US_pre) and post-implant CT (CT_post) studies. Individual sectors were created by dividing prostate into three equal lengths, namely base, midgland, and apex. Each of these volumes was then divided into four axial sectors. Dosimetric parameters were compared in adjoining sectors within each study and between studies.ResultsThere were statistically significant differences between individual sectors on US_pre and CT_post volumes with CT_post higher than US_pre (p = 0.001). Statistically significant differences were found in corresponding sectors on US_pre and CT_post for all dosimetric parameters. The dosimetric parameters were significantly lower on CT_post in the anterior base and midgland (p = 0.001) and significantly higher at the posterior apex and midgland (p = 0.05). Dose homogeneity was demonstrated in adjoining sectors in all US_pre and most adjoining sectors on CT_post.ConclusionsSector analysis allows rapid assessment of US_pre and CT_post dosimetry. It offers a scientific method of identifying areas of increased and reduced dosing on CT_post when compared with US_pre, providing a learning tool to refine dosimetric analysis and highlight sectors where implant quality could be improved.     

Ankle inversion proprioception measured during landing in individuals with and without chronic ankle instability

BackgroundResearch evidence has suggested that a more sensitive ankle proprioceptive testing method with higher ecological validity is needed for assessing proprioceptive deficits in individuals with chronic ankle instability (CAI).Objectives(1) To determine the test–retest reliability of a novel ankle proprioception assessment tool, the Ankle Inversion Discrimination Apparatus for Landing (AIDAL); (2) To assess whether AIDAL scores were sufficiently sensitive to detect proprioceptive deficits in chronic ankle instability (CAI); and (3) To examine whether AIDAL scores correlated with Cumberland Ankle Instability Tool (CAIT) scores.DesignCross-sectional study.MethodsThe AIDAL was purpose-built to assess ankle discrimination in four positions of ankle inversion (10°, 12°, 14° and 16°) upon landing from a 10 cm drop. Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score. Seven-day test–retest reliability was evaluated with 23 university students (12 CAI and 11 non-CAI), and another 36 university students (18 CAI and 18 non-CAI) were in the comparison study.ResultsThe test–retest reliability ICC score for the whole group was 0.763 (95% CI = 0.519–0.892), which showed an excellent reliability level. ICC _(3,1) was 0.701 for the non-CAI group (95%CI = 0.210–0.910) and 0.804 for the CAI group (95%CI = 0.451–0.939). The CAI group performed at a significantly lower level on the AIDAL assessment than the non-CAI group (0.777 ± 0.05 vs. 0.815 ± 0.05, F = 5.107, p = 0.03). The discriminative AUC value for the AIDAL test was 0.756 with a cut point of 0.819 (sensitivity = 0.733, specificity = 0.800). The MDC₉₀ scores for CAI and non-CAI groups were both 0.04. Spearman's correlation showed that the CAIT scores were significantly correlated with the ankle proprioceptive discrimination scores (rho = 0.401, p = 0.015).ConclusionThe AIDAL showed good test–retest reliability for both non-CAI and CAI groups. Measuring ankle inversion proprioception during landing may be important for assessing the outcomes of CAI rehabilitation, as proprioceptive performance obtained from the AIDAL was significantly correlated with severity of functional ankle instability CAIT scores.     

Passive dorsiflexion stiffness is poorly correlated with passive dorsiflexion range of motion

ObjectivesThe purpose of this study was to determine the relationships among passive measures of weight-bearing dorsiflexion range of motion, non-weight-bearing dorsiflexion range of motion and dorsiflexion stiffness, thereby establishing whether they assess similar mechanical characteristics, as each measure has been implicated in injury risk during landings.DesignCross-sectional study.MethodsPassive weight-bearing dorsiflexion range of motion, non-weight-bearing dorsiflexion range of motion and dorsiflexion stiffness were quantified for 42 males (22.8 ± 5.0 years). The relationship between each data set was calculated using Pearson product-moment correlation coefficients.ResultsAlthough weight-bearing dorsiflexion range of motion and non-weight-bearing dorsiflexion range of motion were significantly correlated, the strength of the relationship was poor (r² = 0.18; p = 0.004). Weight-bearing dorsiflexion range of motion (mean = 43.0 ± 5.0°) was significantly greater than non-weight-bearing dorsiflexion range of motion (29.8 ± 5.9°; p < 0.001) and weight-bearing dorsiflexion range of motion and non-weight-bearing dorsiflexion range of motion were also poorly correlated with passive dorsiflexion stiffness (1.48 ± 0.55 Nm °^?1; r² = 0.04 and r² = 0.14, respectively), despite the latter relationship being significant (p = 0.017).ConclusionsPassive dorsiflexion stiffness was not strongly associated with dorsiflexion range of motion, despite the significant correlation in the non-weight-bearing condition. It must be acknowledged that passive dorsiflexion stiffness was weakly associated with dorsiflexion range of motion, although the strength of the association suggests that it may not necessarily determine dorsiflexion range of motion. Furthermore, the functional dorsiflexion limits of the ankle during weight-bearing tasks may be underestimated or misrepresented by non-weight-bearing measures of dorsiflexion range of motion. Therefore, although ankle dorsiflexion range of motion and dorsiflexion stiffness have been implicated in injury risk during weight-bearing tasks such as landings, it may be due to different mechanisms.     

A new method for measuring AFO deformation,tibial and footwear movement in three dimensional gait analysis

Solid ankle-foot orthoses (AFOs) are designed to immobilise the ankle but numerous studies have measured a considerable ankle range of motion (ROM) in AFO users. Measurement of ankle kinematics may be affected by soft-tissue artefact (STA) of the knee marker, deformation of the AFO or tibial movement within the AFO. A new model based on the Conventional Gait Model (CGM) was developed to calculate these effects. Although movement of the AFO within the shoe should not affect the measured ankle joint angle the model also allows an estimation of this movement.Seven children (13 limbs) with spastic diplegic cerebral palsy were assessed to present the benefits of the new model compared to the CGM. STA of the knee marker was estimated to result in a 1.5° overestimation of total ankle ROM (from 8.2° to 9.7°). STA error was strongly related to angle of knee flexion (r = 0.82) with an average maximum error of 3.8°. AFO deformation contributed approximately two thirds of the ankle ROM (6.0 ± 4.3°) with the remaining third from tibial movement relative to the AFO (2.8 ± 0.9°). Movement of the AFO within the footwear was very small (1.8 ± 0.8°). A strong positive relationship (r = 0.9) was found between body mass (kg) and AFO deformation which was statistically significant (p < 0.001). This is the first model to attempt to quantify different contributions to ankle dorsiflexion measured during gait analysis of people wearing AFOs.     

Normative reference values for handgrip strength,shoulder and ankle range of motion and upper-limb and lower limb stability for 137 youth judokas of both sexes

ObjectivesTo provide reference values for handgrip strength, shoulder and ankle range of motion (ROM) and upper-limb and lower limb stability for youth judokas of both sexes and investigate the effects of sex and side dominance.DesignCross-sectional.MethodsA total of 137 youth judokas from under-18 (n = 60) and under-21 (n = 77) categories of both sexes were assessed. Handgrip strength was assessed using a Jamar dynamometer, ankle ROM was measured by lunge test, shoulder ROM was assessed by an inclinometer and upper-limb and lower limb stability were assessed by the Closed Kinetic Chain Upper Extremity Stability Test and by the Modified Star Excursion Balance Test (mSEBT).ResultsIn both categories, males had greater handgrip strength. In the under-18 category, the dominant side had greater handgrip strength, the non-dominant side of females had smaller shoulder external rotation ROM than the dominant side and also than both sides of males, and females had greater shoulder IR ROM. In the under-21 category, the dominant side of females had greater ankle dorsiflexion ROM than the dominant side of males, the dominant sides and females had greater shoulder ER ROM, and males had better performance in the mSEBT.ConclusionsThis study provided reference values for handgrip strength, shoulder and ankle ROM, upper and lower limb stability for youth judokas, which can be used to guide assessment during preseason. Sex influenced on shoulder ER and IR ROM, handgrip strength and lower limb stability. In addition, side dominance influenced on shoulder ER ROM and on handgrip strength.     

Dorsiflexion and dynamic postural control deficits are present in those with chronic ankle instability

ObjectivesTo determine if differences in weight-bearing ankle dorsiflexion range of motion (DFROM) and Star Excursion Balance Test (SEBT) reach distances were present between participants with chronic ankle instability (CAI) and healthy individuals. A secondary objective was to re-examine the relationship between these measures in participants with and without CAI.DesignCase–control.MethodsThirty participants with CAI were matched to 30 healthy participants. All participants performed maximum reach in the anterior, posteromedial and posterolateral directions of the SEBT; as well as, the Weight-Bearing Lunge Test (WBLT) to measure DFROM. Dependent variables included maximal DFROM (cm) and normalized SEBT reach distances (%). Independent t-tests were used for group comparisons (a priori p ≤ 0.05). Simple-linear regression examined the relationship between the WBLT and each SEBT direction.ResultsSignificant differences were detected between groups for the WBLT (CAI: 10.73 ± 3.44 cm, healthy: 12.47 ± 2.51 cm; p = 0.03) and anterior reach distance (CAI: 76.05 ± 6.25%, healthy: 80.12 ± 5.88%; p = 0.01). No differences were identified in posteromedial or posterolateral (ps > 0.70) reach. The WBLT had a significant moderate correlation to anterior reach in both groups (ps < 0.05) but was not significantly correlated to posteromedial or posterolateral reach distance (ps > 0.70).ConclusionsThe results indicate that participants with CAI demonstrated less DFROM and anterior SEBT reach distance compared to health controls. Additionally, both groups demonstrated similar correlations between WBLT and SEBT performance. These findings suggest that participants with CAI have alterations in ankle motion which may negatively influence dynamic postural control; however, the relationship between WBLT and SEBT performance is consistent in those with and without CAI.     

Functional performance deficits associated with ligamentous instability at the ankle

ObjectivesTo examine whether ankle anterior drawer ligament laxity is associated with deficits in performance testing among otherwise healthy sportspeople.DesignCross-sectional cohort study.MethodsEighty-six volunteers from among sports participants at a military academy consented to the use of their pre-participation musculoskeletal screening information for the lower limb, and to an additional test of ankle proprioception. The lower limb screening included tests of ankle ligament laxity, dorsiflexion range of movement, single leg hop-for-distance, hexagon agility hopping test, and hop-and-hold landing stability test.ResultsThere was a significant difference between lax and stable ankles on the 4 screening tests when they were examined together with MANOVA (F = 3.52, df = 4, 167, p = 0.009, Wilks’ Lambda = 0.92). Independent t-tests showed worse performance on the hop-for-distance (p = 0.001), hexagon hop (p = 0.039) and the proprioception tests (p = 0.033) associated with laxity. Comparing stable and unstable ankles in the same individual, paired t-tests showed significantly lower hop counts for lax ankles on the hexagon hop test (p = <0.001).ConclusionsAnkle ligament laxity is associated with persisting deficits in explosive power, agility and proprioception, as demonstrated by less hopping distance, fewer hops in hexagon hop testing, and reduced proprioceptive acuity, despite ongoing participation in sport. Attention to maximising sport-related performance in the late stages of rehabilitation is suggested as an essential addition to clinical management of these injuries.     

The influence of ankle dorsiflexion and self-reported patient outcomes on dynamic postural control in participants with chronic ankle instability

We investigated the influence of ankle dorsiflexion range of motion (DF-ROM) and self-reported patient outcomes on dynamic postural control assessed with the Star Excursion Balance Test (SEBT) in individuals with chronic ankle instability (CAI). Twenty-nine participants with self-reported CAI volunteered. The primary outcome measurements were categorized into clinician-and patient-generated. Clinician-generated outcome measurements included anterior (SEBT-A), posteriormedial (SEBT-PM) and posteriorlateral (SEBT-PL) reach distances (cm) normalized by leg length (cm) of the SEBT, maximum weight-bearing dorsiflexion (WB-DF) (cm), and open-chain DF-ROM (°). Self-reported patient-generated outcome measures included the foot and ankle ability measure and the level of perceived pain, stiffness, stability, and function of their involved ankle on a 10-cm visual analog scale (VAS). Pearson product moment correlations were used to examine the relationship of the SEBT performances with DF-ROM and self-reported patient outcome measures. A multiple linear regression was performed to determine the influence of patient- and clinician-generated measures on the SEBT. SEBT-A performance was significantly and fairly correlated with WB-DF (r = 0.410, p = 0.014), perceived ankle stiffness (r = 0.477, p = 0.014), and open-chain DF-ROM (r = 0.404, p = 0.015). The strongest predictor of the variance in SEBT-A was the combination of the variance in WB-DF and VAS-stiffness (R² = 0.348, p = 0.004). There were no significant correlations with the SEBT-PM and SEBT-PL. WB-DF and VAS-stiffness may represent targets for intervention that need to be addressed to produce the best outcome in participants with CAI when altered dynamic postural control is detected on the SEBT-A.     

A comprehensive evaluation of the variation in ankle function during gait in children and youth with Charcot–Marie–Tooth disease

A better understanding of gait dysfunction for children and youth with Charcot–Marie–Tooth (CMT) will assist in developing appropriate treatments and understanding prognosis for ambulation. The purpose of this retrospective study was to document the typical gait patterns in children and youth (12 ± 4 years) with CMT using motion analysis and relate these findings back to the clinical assessment at the ankle. All patients underwent a motion analysis as a component of treatment decision-making.Lower extremity kinematics and kinetics were evaluated in comparison to a typically developing age-matched reference control group collected in the same gait laboratory. Three patient subgroups were defined based on peak ankle dorsiflexion in terminal stance: greater than typical (n = 23), within typical range (n = 30) and less than typical (n = 13). The three subgroups showed statistically significant differences (p < 0.004) in degree of impairment for ankle plantar flexor and dorsiflexor weakness and ankle plantar flexor contracture. Patients with excessive dorsiflexion in terminal stance had the greatest ankle plantar flexor weakness (median 2) and the greatest dorsiflexor weakness (median 4). Patients with less than typical dorsiflexion in terminal stance were the only patients with a plantar flexor contracture (?2 ± 9°). Delayed peak dorsiflexion in stance was the most common kinematic finding and consistent with ankle plantar flexor weakness. All patients showed significantly less (p < 0.001) peak ankle moments and power generation in terminal stance than the typically developing controls. We concluded that children and youth with CMT present differently in terms of impairment and associated gait issues which therefore require patient specific treatment strategies.     

Normative EMG patterns of ankle muscle co-contractions in school-age children during gait

PurposeThe study was designed to assess the co-contractions of tibialis anterior (TA) and gastrocnemius lateralis (GL) in healthy school-age children during gait at self-selected speed and cadence, in terms of variability of onset-offset muscular activation and occurrence frequency.MethodsStatistical gait analysis, a recent methodology performing a statistical characterization of gait by averaging spatio-temporal and sEMG-based parameters over numerous strides, was performed in 100 healthy children, aged 6-11 years. Co-contractions were assessed as the period of overlap between activation intervals of TA and GL.ResultsOn average, 165 ± 27 strides were analyzed for each child, resulting in approximately 16,500 strides. Results showed that GL and TA act as pure agonist/antagonists for ankle plantar/dorsiflexion (no co-contractions) in only 19.2 ± 10.4% of strides. In the remaining strides, statistically significant (p < 0.05) co-contractions appear in early stance (46.5 ± 23.0% of the strides), mid-stance (28.8 ± 15.9%), pre-swing (15.2 ± 9.2%), and swing (73.2 ± 22.6%). This significantly increased complexity in muscle recruitment strategy beyond the activation as pure ankle plantar/dorsiflexors, suggests that in healthy children co-contractions are likely functional to further physiological tasks as balance improvement and control of joint stability.ConclusionsThis study represents the first attempt for the development in healthy children of a normative dataset for GL/TA co-contractions during gait, achieved on an exceptionally large number of strides in every child and in total. The present reference frame could be useful for discriminating physiological and pathological behavior in children and for designing more focused studies on the maturation of gait.     

Cognitive loading-induced sway alterations are similar in those with chronic ankle instability and uninjured controls

Performing a cognitive task while balancing can result in either increased or decreased sway depending on the nature of the cognitive task, and is commonly used in pathologic populations to evaluate postural performance. A total of 39 participants were recruited into two groups: uninjured controls (n = 20, age: 21.9 ± 2.1 years, height: 175.0 ± 11.2 cm, mass: 71.3 ± 14.9 kg) and chronic ankle instability (n = 19, age: 22.1 ± 5.6 years, height: 169.7 ± 7.7 cm, mass: 72.9 ± 17.3 kg). Participants were asked to perform one of three cognitive tasks while maintaining single limb balance. Cognitive tasks included backwards counting by 3 (BC), the manikin test (MAN), and random number generation (RNG). Time-to-boundary minima, mean, and standard deviations were calculated and compared between groups as pre to post change scores. Effect sizes and 95% confidence intervals were also calculated to test for group differences and the effect of task performance on sway. No significant main effects of Group or Group by Task interactions were identified (p > 0.05). However, a significant multivariate main effect of Task was identified in BC (p = 0.001, F(6, 32) = 4.804) and RNG (p < 0.001, F(6, 32) = 6.233) but not for MAN (p = 0.117). The results suggest that those with chronic ankle instability and uninjured controls have similar postural–suprapostural interactions across multiple cognitive task domains. Both the BC and RNG tasks resulted in less sway for all participants. Our results suggest that dual-task interference in the CAI population may not be present as previous research would suggest.     

The influence of ankle support on postural control

Postural control assessments are commonly administered to athletes as part of a pre-season screening. Establishing a baseline level of function permits the clinician to compare post-injury results to normal functioning during the return to play decision-making process. In the athletic setting, follow-up tests may be completed on the sideline immediately following injury. We sought to examine the effect of commonly administered external ankle joint support on postural control using the balance error scoring system (BESS) and the NeuroCom sensory organization test (SOT). Nineteen volunteers free from balance issues completed three sessions with varied ankle support: bilateral prophylactic ankle taping, laced bracing device, or barefoot. Each session included an initial balance assessment on the BESS and SOT, a 20 min treadmill walk, and post-walk balance test. Fewer errors, indicating improved balance, were committed on the BESS during the barefoot condition than the braced ankle condition (p = 0.044) at the pre-walk assessment. During the post-walk assessment, fewer errors were committed during the barefoot condition compared to the braced ankle condition (p = 0.034) and the taped ankle condition (p = 0.037). All ankle support conditions showed similar improvements in balance between the pre and post-walk assessments on the BESS (p < 0.001) and SOT composite balance score (p = 0.009). These findings indicate that ankle support devices may influence postural control on the BESS, but not on the NeuroCom SOT. Clinicians using the BESS as a balance assessment device at multiple time points should be consistent in the application of ankle support devices.     

Functional differences in softball pitchers with and without upper extremity pain

ObjectivesThough pitchers often throw during multiple games in a day, there are currently no pitch count restrictions in softball. The accumulation of high pitch counts over time may contribute to the development of upper extremity pain. The purpose of our study was to examine functional characteristics of shoulder and hip range of motion (ROM), isometric strength (ISO), and ball speed in softball pitchers with and without upper extremity (UE) pain.DesignControlled laboratory design.MethodsFifty-three NCAA Division I softball pitchers (20.0 ± 1.4 years; 173.3 ± 8.3 cm; 80.9 ± 12.3 kg) participated and were divided into two groups: pain-free (n = 30) and pain in the UE (n = 23). Bilateral shoulder and hip external rotation (ER) and internal rotation (IR) ROM and ISO were measured prior to pitching to a catcher located 13.1 m (43 ft) away.ResultsIndependent samples t-tests revealed significantly greater throwing side (TS) hip ER ROM (p = 0.012), TS hip IR ISO (p = 0.038), glove side (GS) hip ER ISO (p = 0.025), TS shoulder ER ISO (p = 0.002), GS shoulder IR (p = 0.006) and ER (p = 0.004) ISO in the pain free group versus the UE pain group.ConclusionsDifferences in shoulder and hip ROM and ISO exist between those who have upper extremity pain and those who do not. Therefore, findings suggest that both the upper and lower extremities should be considered when treating softball pitchers with UE pain.     

Dynamic joint stiffness of the ankle during walking: Gender-related differences

ObjectivesTo characterize and compare dynamic joint stiffness (DJS) of the ankle in the sagittal plane during natural cadence walking in both genders.DesignObservation, cross-sectional and matched pairs.ParticipantsTwenty-one males (mean age=27±4.2 years) and 18 females (mean age=22.9±4.1 years).SettingLaboratory at the University de Trás-os-Montes and Alto Douro. The DJS of the ankle was assessed while participants performed barefoot walking at a natural cadence, was measured using a force platform (1000 Hz), and synchronized with a high-speed camera (200 Hz).Main outcome measuresDJS of the ankle in males and females was calculated in two sub-phases (the second and the fourth sub-phases) of the stance phase. The Wilcoxon non-parametric matched-pairs test and the Mann–Whitney U non-parametric test were used to analyse difference of DJS of the ankle within and between the groups with p⩽0.05 regarded as significant.ResultsMale and female participants demonstrated significantly (p<0.005) less DJS during the second sub-phase. DJS was not significantly (p>0.063) different between females (0.0511 N m/kg/°) and males (0.0596 N m/kg/°) during the second sub-phase. DJS was significantly (p<0.001) higher in males (0.0844 N m/kg/°) than females (0.0691 N m/kg/°) during the fourth sub-phase.ConclusionsGender-specific DJS characteristics demonstrated by females in this study may be used in preventative training programs designed to promote a greater ability to use contractile components to produce mechanical energy through the ankle.     

Prescribing joint co-ordinates during model preparation in OpenSim improves lower limb unplanned sidestepping kinematics

ObjectivesInvestigate how prescribing participant-specific joint co-ordinates during model preparation influences the measurement agreement of inverse kinematic (IK) derived unplanned sidestepping (UnSS) lower limb kinematics in OpenSim in comparison to an established direct kinematic (DK) model.DesignParallel forms repeatability.MethodsThe lower limb UnSS kinematics of 20 elite female athletes were calculated using: 1) an established DK model (criterion) and, 2) two IK models; one with (IK_PC) and one without (IK₀) participant-specific joint co-ordinates prescribed during the marker registration phase of model preparation in OpenSim. Time-varying kinematic analyses were performed using one dimensional (1D) statistical parametric mapping (α = 0.05), where zero dimensional (0D) Root Mean Squared Error (RMSE) estimates were calculated and used as a surrogate effect size estimates.ResultsStatistical differences were observed between the IK_PC and DK derived kinematics as well as the IK₀ and DK derived kinematics. For the IK_PC and DK models, mean kinematic differences over stance for the three dimensional (3D) hip joint, 3D knee joint and ankle flexion/extension (F/E) degrees of freedom (DoF) were 46 ± 40% (RMSE = 5 ± 5°), 56 ± 31% (RMSE = 7 ± 4°) and 3% (RMSE = 2°) respectively. For the IK₀ and DK models, mean kinematics differences over stance for the 3D hip joint, 3D knee joint and ankle F/E DoF were 70 ± 53% (RMSE = 14 ± 11°), 46 ± 48% (RMSE = 8 ± 7°) and 100% (RMSE = 11°) respectively.ConclusionsPrescribing participant-specific joint co-ordinates during model preparation improves the agreement of IK derived lower limb UnSS kinematics in OpenSim with an established DK model, as well as previously published in-vivo knee kinematic estimates.     

The stratification of severity of acute radiation proctopathy after radiotherapy for cervical carcinoma using diffusion-weighted MRI

ObjectiveTo determine whether diffusion-weighted imaging (DWI) can be used for quantitatively evaluating severity of acute radiation proctopathy after radiotherapy for cervical carcinoma.Materials and methodsOne hundred and twenty-four patients with cervical carcinoma underwent MR examination including DWI before and after radiotherapy. Acute radiation proctopathy was classified into three groups (grade 0, grade I–II and grade III–IV) according to Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG). The pretreatment ADC (ADC_pre), ADC after treatment (ADC_post) and ADC change (ΔADC) were compared among three groups. In addition, acute radiation proctopathy was classified into good-prognosis group and poor-prognosis group. ADC_pre, ADC_post and ΔADC were compared between two groups. For DWI parameter that had significant difference, discriminatory capability of the parameter was determined using receiver operating characteristics (ROC) analysis.ResultsADC_post and ΔADC were higher in grade I–II group than in grade 0 group (p < 0.05), yielding a sensitivity of 79.3% and specificity of 69.4% for ADC_post, and 85.1%, 72.3% for ΔADC for discrimination between two groups. ADC_post and ΔADC were higher in grade III–IV group than in grade I–II group (p < 0.05), yielding a sensitivity of 80.3% and specificity of 72.5% for ADC_post, and 84.1%, 74.5% for ΔADC for discrimination between two groups. ADC_post and ΔADC were higher in poor-prognosis group than in good-prognosis group (p < 0.05), yielding a sensitivity of 79.5% and specificity of 73.4% for ADC_post, and 87.2%, 78.3% for ΔADC for discrimination between two groups.ConclusionDiffusion-weighted MRI can be used for quantitative stratification of severity of acute radiation proctopathy, which serves as an important basis for appropriate timely adjustment of radiotherapy for cervical carcinoma in order to maximally reduce the radiation injury of rectum.