+55 (51) 4066 3333 [email protected]
Scientific Reports – Volume 8, Article number: 2300 (2018)

Movement Strategies for Countermovement Jumping are Potentially Influenced by Elastic Energy Stored and Released from Tendons

Logan Wade, Glen Lichtwark & Dominic James Farris


The preferred movement strategies that humans choose to produce work for movement are not fully understood. Previous studies have demonstrated an important contribution of elastic energy stored within the Achilles tendon (AT) during jumping. This study aimed to alter energy available for storage in the AT to examine changes in how jumpers distribute work among lower limb joints. Participants (n = 16) performed maximal and sub-maximal jumps under two paradigms, matched for increasing total work output by manipulating jump height or adding body mass. Motion capture and ground reaction force data were combined in an inverse dynamics analysis to compute ankle, knee and hip joint kinetics. Results demonstrated higher peak moments about the ankle joint with added body mass (+26 Nm), likely resulting in additional energy storage in the AT. Work at the ankle joint increased proportionally with added mass, maintaining a constant contribution (~64%) to total work that was not matched with increasing jump height (−14%). This implies greater energy storage and return by the AT with added mass but not with increased height. When total work during jumping is constant but energy stored in tendons is not, humans prioritise the use of stored elastic energy over muscle work.

British Journal of Sports Medicine – Volume 42, Issue 6

Are the take-off and landing phase dynamics of the volleyball spike jump related to patellar tendinopathy?

R W Bisseling, A L Hof, S W Bredeweg, J Zwerver, T Mulder


Objective: The causal mechanism of the chronic sports injury patellar tendinopathy is not well understood. The aim of the present study was to compare ankle and knee joint dynamics during the performance of the volleyball spike jump between healthy volleyball players (n = 8) and asymptomatic volleyball players with previous patellar tendinopathy (n = 7).

Design: Cross-sectional.

Methods: Inverse dynamics were used to estimate ankle and knee joint dynamics. From these multiple biomechanical variables, a logistic regression was performed to estimate the probability of the presence or absence of previous patellar tendinopathy among the volleyball players studied.

Results: Several biomechanical variables improved the prediction of the presence or absence of previous patellar tendinopathy. For landing, ankle plantar flexion at the time of touch-down, and knee range of motion during the first part of impact, and for take-off, loading rate of the knee extensor moment during the eccentric countermovement phase of take-off were predictive. As interaction effects, the presence or absence of previous patellar tendinopathy were correctly predicted by ankle and knee range of motion during the first part of impact, by loading rate of the knee extensor moment during the eccentric phases of take-off and landing, and by knee angular velocity during the eccentric phases of take-off and landing.

Conclusion: Smaller joint flexion during the first part of landing impact , and higher rate of knee moment development during the eccentric phases of the spike-jump landing sequence, together with higher knee angular velocities, might be risk factors in the development of patellar tendinopathy in volleyball players.

Neuropediatrics 2016;47:162–168.

Does Botulinum Toxin A Treatment Enhance the Walking Pattern in Idiopathic Toe-Walking?

Heli Sätilä, Anneli Beilmann, Päivi Olsén, Heli Helander, Mari Eskelinen, Heini Huhtala


Objective: We conducted a randomized controlled trial to evaluate whether a combinationof repeated botulinum toxin A (BTX-A) and conservative treatment is moreeffective in decreasing toe-walking than conservative treatment alone at 24 monthsfollow-up.

Patients and Methods Children: between 2 and 9 years of age were randomized eitherinto the conservative (CO) or botulinum treatment (BTX) group. The treatment in theCO group consisted of firm shoes, night splints, a home stretching program andphysiotherapy. The BTX arm had all the same conservative treatments added with calfmuscle BTX-A injections repeated in 6months intervals if needed. Change in toe-walkingpattern, ankle range ofmovement (ROM), and overall function were assessed at baselineand 6, 12, 18, and 24 months posttreatment.

Results: A total of 30 toe-walkers participated: 14 in CO and 16 in BTX group. At24 months, all children in the BTX group and 85% in the CO group evaluated by theblinded physiotherapist (p ¼ 0.065), 75% in the BTX group and 70% in the CO groupgraded by the research physiotherapist (p ¼ 0.730), and 50% in the BTX group and 54%in the CO group reported by the parents ceased toe-walking (p ¼ 0.837). The mostprominent change was noted during the 1st year. The BTX group seemed to reach thegoal earlier. No significant differences between the treatment groups in function or inankle ROM ensued.

Conclusion: Adding BTX injections did not significantly enhance the goal to walk eitherflat foot or with heel strike at 24 months posttreatment.

Clinical Orthopaedics and Related Research (2011) 469:1308–1314

What Variables Influence the Ability of an AFO to Improve Function and When Are They Indicated?

Bryan S. Malas CO, MHPE


Background: Children with spina bifida often present with functional deficits of the lower limb associated with neurosegmental lesion levels and require orthotic management.The most used orthosis for children with spina bifida is theankle–foot orthosis (AFO). The AFO improves ambulationand reduces energy cost while walking. Despite theapparent benefits of using an AFO, limited evidencedocuments the influence of factors predicting the ability ofan AFO to improve function and when they are indicated.These variables include AFO design, footwear, AFO–footwear combination, and data acquisition. When thesevariables are not adequately considered in clinicaldecision-making, there is a risk the AFO will be abandonedprematurely or the patient’s stability, function, and safetycompromised.Purpose The purposes of this study are to (1) describe thefunctional deficits based on lesion levels; (2) identify anddescribe variables that influence the ability of an AFO tocontrol deformities; and (3) describe what variables areindicated for the AFO to control knee flexion during stance,hyperpronation, and valgus stress at the knee.Methods A selective literature review was undertakensearching MEDLINE and Cochrane databases using termsrelated to ‘‘orthosis’’ and ‘‘spina bifida.’’Results Based on previous studies and gait analysis data,suggestions can be made regarding material selection/geometric configuration, sagittal alignment, footplatelength, and trim lines of an AFO for reducing knee flexion,hyperpronation, and valgus stress at the knee.Conclusion Further research is required to determinewhat variables allow an AFO to improve function.

Muscle & Nerve – DOI 10.1002/mus.24081

Leg Muscle Function And Fatigue During Walking In Spinal Muscular Atrophy Type 3

Jacqueline Montes, Sally Dunaway, Carol Ewing Garber, Claudia A. Chiriboga, Darryl C. De Vivo, And Ashwini K. Rao


Introduction: Spinal muscular atrophy (SMA) causes muscle weakness and fatigue. Better understanding of the relationship between weakness and fatigue may help identify potential targets for rehabilitation. Methods: Gait and surface electromyography (EMG) from 4 muscle groups were measured during the Six-Minute Walk Test (6MWT) in 10 ambulatory participants, aged 9–49 years. Average root mean square amplitude (RMS) of muscle activity was calculated. Strength was assessed using manual and quantitative methods. Results: RMS, stride length, and velocity decreased during the 6MWT. Knee flexor and hip abductor strength was associated with fatigue-related changes; overall strength correlated with disease duration; and leg strength was associated with 6MWT distance. Conclusions: Clinical measures are valid in assessing fatigue and function in SMA, and these assessments can be enhanced by use of gait analysis and EMG. Disease duration and strength measures may represent further stratification refinements when enrolling patients in clinical trials.

Journal of the Peripheral Nervous System 21:317–328 (2016)

Gait in children and adolescents with Charcot-Marie-Tooth disease: a systematic review

Rachel A. Kennedy, Kate Carroll, and Jennifer L. McGinley


Symptoms of Charcot-Marie-Tooth (CMT) disease typically arise in childhood or adolescence with gait difficulty most common. A systematic review was conducted to synthesise, review, and characterise gait in paediatric CMT. Health-related electronic databases were reviewed with search terms related to CMT and gait. Of 454 articles, 10 articles describing seven studies met eligibility criteria; samples ranged from 1 to 81, included mixed CMT sub-types and had a participant mean age of 13 years. Assessments included a variety of methods to examine only barefoot gait. Heterogeneity of gait patterns was noted. Children and adolescents with CMT walked slower, most likely due to shorter stride length. Common kinematic and kinetic abnormalities included significant foot drop during swing, reduced calf muscle power, and proximal compensatory mechanisms in the lower limb. Little data were found to inform typical functional gait characteristics or change over time. Of note, barefoot assessment does not reflect function in everyday life where footwear is commonly worn. With limited existing literature, future studies of gait in paediatric CMT need to evaluate the influence of diagnostic sub-types and disease progression; the effect of factors such as footwear and the environment; and to explore changes in gait and function throughout childhood and adolescence.

Footwear Science – Volume 3, 2011 – Issue 3

Influence of footwear on stabilometric dimensions and muscle activity

Pranab Nag, Anjali Nag, Heer Vyas & Priyanka Shah Shukla


Background: Properties of footwear exert an influence on centre of pressure (CoP) displacement parameters, muscle activity and user’s postural control. Thereby, selection of footwear aid to manage postural stability and fall problems.

Objective: The study applies stabilometry, force exertion and electromyography when women stood and walked by donning footwear with different characteristics and in barefoot.

Method: Women volunteers aged (30.2 ± 5.6 year), and having BMI (27.6 ± 7.4) participated in the study. The footwear included in the study were of four different designs, laced shoe (2.5 cm heel), flat heeled (9 cm heel), and pointed heel (7 cm and 13 cm heel). Female subjects (N = 15) stood and walked after putting on footwear and in bare feet.

Results: The weighted force (kgf) distribution derived as the square root of the sum of squares of three forces at x, y and z coordinates was minimal in laced shoes, suggesting the relative stability in comparison to bare feet and other footwear. ANOVA showed that the footwear had discernible effect on the medio-lateral CoP displacement and CoP speed during standing, and anterior posterior CoP range while walking. The leg muscle activity, both soleus and tibaials anterior, was significantly higher in pointed heel (13 cm heel) while standing, suggesting that heels exert an influence on leg muscle activity and postural control mechanism.

Conclusion: Laced shoes gave relatively better postural stability to the wearer.

Potential implications: This work gives a valuable insight to consideration of biomechanical parameters for footwear manufacturers and wearers.


Regular Articles

Influence of footwear on stabilometric dimensions and muscle activity

Pranab Nag,Anjali Nag,Heer Vyas &Priyanka Shah Shukla
National Institute of Occupational H
Regular Articles
Influence of footwear on stabilometric dimensions and muscle activity

Pranab Nag,Anjali Nag,Heer Vyas &Priyanka Shah Shukla
National Institute of Occupational H


Journal of Orthopaedic & Sports Physical Therapy – 2017 Jun;47(6):411-419

Knee Loading Deficits During Dynamic Tasks in Individuals Following Anterior Cruciate Ligament Reconstruction
Pratt KA, Sigward SM


Study Design Controlled laboratory study, cross-sectional. Background Well-documented deficits in sagittal plane knee loading during dynamic tasks indicate that individuals limit the magnitude of knee loading following anterior cruciate ligament reconstruction (ACLR). It is unknown how these individuals modulate the speed of knee flexion during loading, which is particularly important as they progress to running during rehabilitation. Objective To investigate how individuals following ACLR perform dynamic knee loading tasks compared to healthy controls. Methods Two groups of recreationally active individuals participated: 15 healthy controls and 15 individuals post-ACLR (ACLR group). Participants performed 3 trials of overground running and a single-limb loading (SLL) task. Sagittal plane range of motion, peak knee extensor moment, peak knee flexion angular velocity, peak knee power absorption, and rate of knee extensor moment were calculated during deceleration. A mixed-factor multivariate analysis of variance was performed to compare differences in variables between groups (ACLR and control), limbs (within ACLR), and tasks (within control). Results Knee power absorption, knee flexion angular velocity, and rate of knee extensor moment were lower in reconstructed limbs (for the SLL task: 5.6 W/kg, 325.8°/s, and 10.5 Nm/kg/s, respectively; for running: 11.8 W/kg, 421.4°/s, and 38.2 Nm/kg/s, respectively) compared to nonsurgical limbs (for the SLL task: 9.7 W/kg, 432.0°/s, and 19.1 Nm/kg/s, respectively; for running: 18.8 W/kg, 494.1°/s, and 72.8 Nm/kg/s, respectively) during both tasks (P<.001). The magnitudes of between-limb differences in knee flexion angular velocity were similar in both tasks. Conclusion Despite lower loading demands during SLL, individuals post-ACLR exhibit deficits in knee dynamics during SLL and running, suggesting an inability or reluctance to dynamically accommodate forces at the knee when progressing to running in rehabilitation.

Journal of Biomechanics 2016 Feb 8;49(3):496-501

The effect of the stability threshold on time to stabilization and its reliability following a single leg drop jump landing

Fransz DP, Huurnink A, de Boode VA, Kingma I, van Dieën JH


We aimed to provide insight in how threshold selection affects time to stabilization (TTS) and its reliability to support selection of methods to determine TTS. Eighty-two elite youth soccer players performed six single leg drop jump landings. The TTS was calculated based on four processed signals: raw ground reaction force (GRF) signal (RAW), moving root mean square window (RMS), sequential average (SA) or unbounded third order polynomial fit (TOP). For each trial and processing method a wide range of thresholds was applied. Per threshold, reliability of the TTS was assessed through intra-class correlation coefficients (ICC) for the vertical (V), anteroposterior (AP) and mediolateral (ML) direction of force. Low thresholds resulted in a sharp increase of TTS values and in the percentage of trials in which TTS exceeded trial duration. The TTS and ICC were essentially similar for RAW and RMS in all directions; ICC’s were mostly ‘insufficient’ (<0.4) to ‘fair’ (0.4-0.6) for the entire range of thresholds. The SA signals resulted in the most stable ICC values across thresholds, being ‘substantial’ (>0.8) for V, and ‘moderate’ (0.6-0.8) for AP and ML. The ICC’s for TOP were ‘substantial’ for V, ‘moderate’ for AP, and ‘fair’ for ML. The present findings did not reveal an optimal threshold to assess TTS in elite youth soccer players following a single leg drop jump landing. Irrespective of threshold selection, the SA and TOP methods yielded sufficiently reliable TTS values, while for RAW and RMS the reliability was insufficient to differentiate between players.

International Journal of Sports Medicine 2017 Sep;38(10):781-790

Combined Effects of Fatigue and Surface Instability on Jump Biomechanics in Elite Athletes

Prieske O, Demps M, Lesinski M, Granacher U


The present study aimed to examine the effects of fatigue and surface instability on kinetic and kinematic jump performance measures. Ten female and 10 male elite volleyball players (18±2 years) performed repetitive vertical double-leg box jumps until failure. Pre and post fatigue, jump height/performance index, ground reaction force and knee flexion/valgus angles were assessed during drop and countermovement jumps on stable and unstable surfaces. Fatigue, surface condition, and sex resulted in significantly lower drop jump performance and ground reaction force (p≤0.031, 1.1≤d≤3.5). Additionally, drop jump knee flexion angles were significantly lower following fatigue (p=0.006, d=1.5). A significant fatigue×surface×sex interaction (p=0.020, d=1.2) revealed fatigue-related decrements in drop jump peak knee flexion angles under unstable conditions and in men only. Knee valgus angles were higher on unstable compared to stable surfaces during drop jumps and in females compared to males during drop and countermovement jumps (p≤0.054, 1.0≤d≤1.1). Significant surface×sex interactions during countermovement jumps (p=0.002, d=1.9) indicated that knee valgus angles at onset of ground contact were significantly lower on unstable compared to stable surfaces in males but higher in females. Our findings revealed that fatigue and surface instability resulted in sex-specific knee motion strategies during jumping in elite volleyball players.

PLoS ONE vol. 11, no.6.

Coactivation of Lower Limb Muscles during Gait in Patients with Multiple Sclerosis

Julien Boudarham, Sophie Hameau, Raphael Zory, Alexandre Hardy, Djamel Bensmail, Nicolas Roche


Background: Coactivation of agonist and antagonist lower limb muscles during gait stiffens joints and ensures stability. In patients with multiple sclerosis, coactivation of lower limb muscles might be a compensatory mechanism to cope with impairments of balance and gait.

Objective: The aim of this study was to assess coactivation of agonist and antagonist muscles at the knee and ankle joints during gait in patients with multiple sclerosis, and to evaluate the relationship between muscle coactivation and disability, gait performance, dynamic ankle strength measured during gait, and postural stability.

Methods: The magnitude and duration of coactivation of agonist-antagonist muscle pairs at the knee and ankle were determined for both lower limbs (more and less-affected) in 14 patients with multiple sclerosis and 11 healthy subjects walking at a spontaneous speed, using 3D-gait analysis.

Results: In the patient group, coactivation was increased in the knee muscles during single support (proximal strategy) and in the ankle muscles during double support (distal strategy). The magnitude of coactivation was highest in the patients with the slowest gait, the greatest motor impairment and the most instability.

Conclusion: Increased muscle coactivation is likely a compensatory mechanism to limit the number of degrees of freedom during gait in patients with multiple sclerosis, particularly when postural stability is impaired.

Disability and Rehabilitation

Quantitative assessment of the effects of 6 months of adapted physical activity on gait in people with multiple sclerosis: a randomized controlled trial

Massimiliano Pau, Federica Corona, Giancarlo Coghe, Elisabetta Marongiu, Andrea Loi, Antonio Crisafulli, Alberto Concu, Manuela Galli, Maria Giovanna Marrosu & Eleonora Cocco


Purpose: The purpose of this study is to quantitatively assess the effect of 6 months of supervised adapted physical activity (APA i.e. physical activity designed for people with special needs) on spatio-temporal and kinematic parameters of gait in persons with Multiple Sclerosis (pwMS).

Methods: Twenty-two pwMS with Expanded Disability Status Scale scores ranging from 1.5 to 5.5 were randomly assigned either to the intervention group (APA, n = 11) or the control group (CG, n = 11). The former underwent 6 months of APA consisting of 3 weekly 60-min sessions of aerobic and strength training, while CG participants were engaged in no structured PA program. Gait patterns were analyzed before and after the training using three-dimensional gait analysis by calculating spatio-temporal parameters and concise indexes of gait kinematics (Gait Profile Score – GPS and Gait Variable Score – GVS) as well as dynamic Range of Motion (ROM) of hip, knee, and ankle joints.

Results: The training originated significant improvements in stride length, gait speed and cadence in the APA group, while GPS and GVS scores remained practically unchanged. A trend of improvement was also observed as regard the dynamic ROM of hip, knee, and ankle joints. No significant changes were observed in the CG for any of the parameters considered.

Conclusions: The quantitative analysis of gait supplied mixed evidence about the actual impact of 6 months of APA on pwMS. Although some improvements have been observed, the substantial constancy of kinematic patterns of gait suggests that the full transferability of the administered training on the ambulation function may require more specific exercises.

· Implications for rehabilitation
· Adapted Physical Activity (APA) is effective in improving spatio-temporal parameters of gait, but not kinematics, in people with multiple sclerosis.
· Dynamic range of motion during gait is increased after APA.
· The full transferability of APA on the ambulation function may require specific exercises rather than generic lower limbs strength/flexibility training.

Hip Int. 2009 Jan–Mar;19 Suppl 6:S63–8.

Relationship between kinematic knee deviations and femoral anteversion in children with cerebral palsy.

Piccinini L, Cimolin V, Turconi AC, Galli M.


The aim of the study was to determine the possible correlation between the degree of femoral anteversion and the quantitative data obtained by 3D Gait Analysis (GA) and then to investigate the relationship between femoral anteversion and the reduced knee flexion during swing phase in childrenwith Cerebral Palsy. Twenty-­-seven diplegic children with severe rectus femoris spasticity and 20 healthy children (CG) were considered. Clinical evaluation of femoral anteversion, Duncan Ely test and Gait Analysis were performed in all patients. From Gait Analysis data some indices were identified and calculated and statistical analysis performed. Clinical evaluations made the distinction between patients with excessive femoralanteversion (Group 1) and those with normal value (Group 2). Both groups showed a blunt maximum of knee flexion in swing (KMSw), representative of rectus femoris spasticity, but two different gait strategies were found for the timing of KMSw. Group 1 exhibited a reduced KMSw value with its timing close to normal value and an excessive hip internal rotation (Mean Hip Rotation index), correlated to high femoral anteversion; Group 2 presented a limited KMSw and a significant delay of its timing, with Mean Hip Rotation index close to Control Group. No differences were found for other indices. The results demonstrated that the presence of reduced KMSw only can be directly connected to excessive femoral anteversion; the coexistence of reduced KMSw and its delayed timing reveals that the rectus femoris spasticity may be due to rectus spasticity added to an incorrect motor selective control. The results are clinically crucial for treatment strategies (derotative femoral osteotomy vs rectus transfer).

Research in Developmental Disabilities 35 (2014) 1137–1143

Effects of gastrocnemius fascia lengthening on gait pattern in children with cerebral palsy using the Gait Profile Score

Luiz Alfredo Braun Ferreira, Veronica Cimolin, Pier Francesco Costici, Giorgio Albertini, Claudia Santos Oliveira, Manuela Galli


The aim of the present study was to investigate the efficacy of the GPS regarding the quantification of changes in gait following the gastrocnemius fascia lengthening in children with CP. Nineteen children with CP were selected and evaluated in the preoperative period (PRE session) and approximately one year postoperatively (POST session; mean 13.1  5.1 months) using 3D gait analysis and computing the GPS and GVSs. As the GPS represents the difference between the patient’s data and the average from the reference dataset, the higher the value of GPS is, more compromised gait of the subject. A statistically significant improvement in mean GPS was found in the POST session (PRE: 13.38  58; POST: 10.26  2.418; p < 0.05), with an improvement close to 23%. Moreover, the GVSs demonstrated statistically significant improvements in ankle dorsi-plantarflexion (PRE: 22.20  16.368; POST: 11.50  6.578; p < 0.05) and pelvic rotation (PRE: 9.53  3.878; POST: 6.47  2.988; p < 0.05). A strong correlation (r = 0.75; p < 0.05) was found between the preoperative GPS and the percentage of GPS improvement. The results demonstrated that the gastrocnemius fascia lengthening produced a global gait pattern improvement, as showed by the GPS value, which decreased after surgery. Besides this, the GVS permitted to better evidence the joints more compromised by the pathology and their improvement due to the surgery, in this case not only the GVS of the ankle joint but also of the pelvis were characterized by higher GVS values.

Journal Plos One, 2014, Volume 9, Issue 8

Effect of Transcranial Direct-Current Stimulation Combined with Treadmill Training on Balance and Functional Performance in Children with Cerebral Palsy: A Double-Blind Randomized Controlled Trial

Natália de Almeida Carvalho Duarte, Luanda Andreá Collange Grecco, Manuela Galli, Felipe Fregni, Cláudia Santos Oliveira


Background: Cerebral palsy refers to permanent, mutable motor development disorders stemming from a primary brain lesion, causing secondary musculoskeletal problems and limitations in activities of daily living. The aim of the present study was to determine the effects of gait training combined with transcranial direct-current stimulation over the primary motor cortex on balance and functional performance in children with cerebral palsy.

Methods: A double-blind randomized controlled study was carried out with 24 children aged five to 12 years with cerebral palsy randomly allocated to two intervention groups (blocks of six and stratified based on GMFCS level (levels I-II or level III).The experimental group (12 children) was submitted to treadmill training and anodal stimulation of the primary motor cortex. The control group (12 children) was submitted to treadmill training and placebo transcranial direct-current stimulation. Training was performed in five weekly sessions for 2 weeks. Evaluations consisted of stabilometric analysis as well as the administration of the Pediatric Balance Scale and Pediatric Evaluation of Disability Inventory one week before the intervention, one week after the completion of the intervention and one month after the completion of the intervention. All patients and two examiners were blinded to the allocation of the children to the different groups.

Results: The experimental group exhibited better results in comparison to the control group with regard to anteroposterior sway (eyes open and closed; p,0.05), mediolateral sway (eyes closed; p,0.05) and the Pediatric Balance Scale both one week and one month after the completion of the protocol.

Conclusion: Gait training on a treadmill combined with anodal stimulation of the primary motor cortex led to improvements in static balance and functional performance in children with cerebral palsy.