Does acute passive stretching increase muscle length in children with cerebral palsy?

BackgroundChildren with spastic cerebral palsy experience increased muscle stiffness and reduced muscle length, which may prevent elongation of the muscle during stretch. Stretching performed either by the clinician, or children themselves is used as a treatment modality to increase/maintain joint range of motion. It is not clear whether the associated increases in muscle–tendon unit length are due to increases in muscle or tendon length. The purpose was to determine whether alterations in ankle range of motion in response to acute stretching were accompanied by increases in muscle length, and whether any effects would be dependent upon stretch technique.MethodsEight children (6–14 y) with cerebral palsy received a passive dorsiflexion stretch for 5 × 20 s to each leg, which was applied by a physiotherapist or the children themselves. Maximum dorsiflexion angle, medial gastrocnemius muscle and fascicle lengths, and Achilles tendon length were calculated at a reference angle of 10° plantarflexion, and at maximum dorsiflexion in the pre- and post-stretch trials.FindingsAll variables were significantly greater during pre- and post-stretch trials compared to the resting angle, and were independent of stretch technique. There was an approximate 10° increase in maximum dorsiflexion post-stretch, and this was accounted for by elongation of both muscle (0.8 cm) and tendon (1.0 cm). Muscle fascicle length increased significantly (0.6 cm) from pre- to post-stretch.InterpretationThe results provide evidence that commonly used stretching techniques can increase overall muscle, and fascicle lengths immediately post-stretch in children with cerebral palsy.     

Morphomechanical alterations in the medial gastrocnemius muscle in patients with a repaired Achilles tendon: Associations with outcome measures

BackgroundFunctional deficits are found in ankles that have sustained an Achilles rupture. This study sought to evaluate and compare the morphomechanical characteristics of the medial gastrocnemius muscle in the legs of participants within six months of a unilateral Achilles repair to determine any correlations between those characteristics and objective outcomes and self-reported functional levels.MethodsFifteen participants were assessed via measurements of muscle morphologies (fascicle length, pennation angle, and muscle thickness) in a resting state, the mechanical properties of the proximal aponeurosis of the medial gastrocnemius muscle, the pennation angle during ramping maximal voluntary isometric contractions (MVIC), the heel raise test, and the Taiwan Chinese version of the Lower Extremity Functional Scale (LEFS-TC) questionnaire.FindingsCompared with the non-injured legs, the repaired legs showed a lower muscle fascicle length (mean 4.4 vs. 5.0 cm) and thickness (1.7 vs. 1.9 cm), lower stiffness of the GM tendon and aponeurosis (174.1 vs. 375.6 N/mm), and a greater GM pennation angle (31.2 vs. 28.9°) during 90% MVIC (all p ≤ 0.05). Correlations were found between the morphomechanical results and maximal heel raise heights or the LEFS-TC score, and between the symmetry ratios of the fascicle lengths and the LEFS-TC score.InterpretationThere are decreases in fascicle length, muscle thickness and mechanical properties in the medial gastrocnemius muscles of the participants within the first six months after an Achilles repair. These morphomechanical alterations demonstrate associations with functional levels in the lower extremities and indicated the need for early mobilization of the calf muscles after the repair.     

Hip muscle weakness and reduced joint range of motion in patients with femoroacetabular impingement syndrome: a case-control study

BackgroundFemoroacetabular impingement (FAI) syndrome is a hip joint motion-related clinical disorder characterized by abnormal contact between the hip joint structures. Abnormal hip morphology and joint pain may impair the hip joint range of motion (ROM) and muscle function. However, FAI effects on hip joint ROM and muscle strength remain controversial.ObjectivesThe purpose of this study was to compare hip joint ROM and muscle strength between FAI syndrome patients and healthy controls.MethodsTwenty FAI syndrome male patients and 20 healthy male controls (CG) matched for age (FAI = 28 ± 6 years; CG = 27 ± 5 years), body mass (FAI = 81 ± 12 kg; CG = 80 ± 13 kg) and height (FAI = 177 ± 6 cm; CG = 178 ± 6 cm), participated in the study. Hip joint ROM for flexion, internal rotation and external rotation were assessed through goniometry. Maximal isometric strength for hip flexion, extension, abduction and adduction were evaluated through hand-held dynamometry.ResultsHip joint ROM was significantly lower in FAI syndrome patients compared with CG for passive flexion (−4%; effect size – ES = 0.65), active internal rotation (−42%; ES = 1.60), active external rotation (−28%; ES = 1.46) and passive external rotation (−23%; ES = 1.63). FAI patients’ hip extensors (−34%; ES = 1.46), hip adductors (−33%; ES = 1.32), and hip flexors (−25%; ES = 1.17) were weaker compared to the CG subjects.ConclusionsFAI syndrome patients presented both hip muscle weakness and reduced joint ROM compared to match CG.     

Lower limb muscle volume estimation from maximum cross-sectional area and muscle length in cerebral palsy and typically developing individuals

BackgroundDeficits in muscle volume may be a significant contributor to physical disability in young people with cerebral palsy. However, 3D measurements of muscle volume using MRI or 3D ultrasound may be difficult to make routinely in the clinic. We wished to establish whether accurate estimates of muscle volume could be made from a combination of anatomical cross-sectional area and length measurements in samples of typically developing young people and young people with bilateral cerebral palsy.MethodsLower limb MRI scans were obtained from the lower limbs of 21 individuals with cerebral palsy (14.7 ± 3 years, 17 male) and 23 typically developing individuals (16.8 ± 3.3 years, 16 male). The volume, length and anatomical cross-sectional area were estimated from six muscles of the left lower limb.FindingsAnalysis of Covariance demonstrated that the relationship between the length*cross-sectional area and volume was not significantly different depending on the subject group. Linear regression analysis demonstrated that the product of anatomical cross-sectional area and length bore a strong and significant relationship to the measured muscle volume (R² values between 0.955 and 0.988) with low standard error of the estimates of 4.8 to 8.9%.InterpretationThis study demonstrates that muscle volume may be estimated accurately in typically developing individuals and individuals with cerebral palsy by a combination of anatomical cross-sectional area and muscle length. 2D ultrasound may be a convenient method of making these measurements routinely in the clinic.     

Coordination between pelvis and shoulder girdle during walking in bilateral cerebral palsy

BackgroundStudies revealed that pelvis and shoulder girdle kinematics is impaired in children with the diplegic form of bilateral cerebral palsy while walking. The features of 3D coordination between these segments, however, have never been evaluated.MethodsThe gait analyses of 27 children with bilateral cerebral palsy (18 males; mean age 124 months) have been retrospectively reviewed from the database of a Movement Analysis Laboratory. The spatial–temporal parameters and the range-of-motions of the pelvis and of the shoulder girdle on the three planes of motion have been calculated. Continuous relative phase has been calculated for the 3D pelvis–shoulder girdle couplings on the transverse, sagittal and frontal planes of motion to determine coordination between these segments. Data from 10 typically developed children have been used for comparison.Findings: Children with bilateral cerebral palsy walk with lower velocity (P = 0.01), shorter steps (P < 0.0001), larger base of support (P < 0.01) and increased duration of the double support phase (P = 0.005) when compared to typically developed children. The mean continuous relative phase on the transverse plane has been found lower in the cerebral palsy group throughout the gait cycle (P = 0.003), as well as in terminal stance, pre-swing and mid-swing. The age, gait speed and pelvis range-of-motions on the transverse plane have been found correlated to continuous relative phase on the transverse plane.Interpretation: Compared with typically developed children, children with bilateral cerebral palsy show a more in-phase coordination between the pelvis and the shoulder girdle on the transverse plane while walking.     

Biomechanical properties of different techniques used in vitro for suturing mid-substance Achilles tendon ruptures

BackgroundThe Dresden technique preserves the paratenon during Achilles tendon repair and may improve the plantarflexor mechanism when combined with mobilization during early rehabilitation. However, the surgical repair design for Achilles tendon ruptures can affect rates of re-rupture or lengthening. Therefore, the aim of this study was to determine the biomechanical properties of the Krackow, Double-Kessler, Double-Dresden, and Triple-Dresden techniques used for repairing mid-substance Achilles tendon ruptures during cyclical and maximum traction.MethodsSixty mid-substance bovine tendons repaired after transverse rupturing were divided randomly into four groups by repair technique: Krackow, Double-Kessler, Double-Dresden, and Triple-Dresden. Cyclical tractions of 4.7, 5.8, 7.9, and 11.7 mm (equivalent to 5°, 8°, 10°, and 15° of dorsal flexion, respectively) were applied to determine gapping, tensile strength, nominal suture stress, repair deformation, and specimens with clinical failure (gap > 5 mm). Maximal traction was applied to measure maximum strength and failure type (i.e. suture, knot, or tendon).FindingsThe Triple-Dresden technique resulted in decreased gapping, nominal suture stress, repair deformation, and quantity of specimens with clinical failure as compared to the other techniques. Furthermore, Triple-Dresden tendons showed greater comparative tensile and maximum strength. During maximal traction testing, this technique presented tendon failure, whereas the Krackow, Double-Kessler, and Double-Dresden techniques had suture failures.InterpretationTriple-Dresden repair results in better cyclical and maximum traction strengths, suggesting that this technique might be more appropriate when performing early mobilization after mid-substance Achilles tendon rupture repair.     

Shoulder muscle atrophy and its relation to strength loss in obstetrical brachial plexus palsy

BackgroundTreatment/prevention of shoulder muscle strength imbalances are major therapeutic goals for children with obstetrical brachial plexus palsy. The study aims were to characterize muscle atrophy in children/adolescents with unilateral obstetrical brachial plexus palsy, to quantify the agonist-antagonist muscle volume balance and the association between muscle volume and strength.MethodsEight boys and four girls (age = 12.1, standard deviation = 3.3) participated in this case-control study. Three-dimensional magnetic resonance images of both shoulders were acquired. The unimpaired shoulder served as a reference. Volumes of deltoid, pectoralis major, supraspinatus, infraspinatus, teres major, subscapularis were calculated based on 3D models, derived through image segmentation. Maximal isometric torques were collected in six directions.FindingsAll the major muscles studied were significantly atrophied. The teres major demonstrated the biggest difference in atrophy between groups (51 percentage points), the pectoralis major was the least atrophied (23 percentage points). The muscle volume distribution was significantly different between shoulders. Muscle volume could predict maximal voluntary isometric torques, but the regression coefficients were weaker on the impaired side (72% to 91% of the strength could be predicted in the uninvolved side and 24% to 90% in the involved side and external rotation strength could not be predicted).InterpretationThis study demonstrates muscle atrophy varied across all the main shoulder muscles of the glenohumeral joint, leading to significant muscle volume imbalances. The weaker coefficients of determination on the impaired side suggest that other variables may contribute to the loss of strength in addition to atrophy.     

Rehabilitation of 190 non-ambulatory children with cerebral palsy in structures of care or in liberal sector

AimsTo describe the rehabilitation of non-ambulatory children with cerebral palsy and to explore adjustability on their individual needs.Material and methodData described are extracted from an on-going national cohort study, following during 10 years 385 children with cerebral palsy, aged from 4 to 10, Gross Motor Function Classification System IV and V. We analysed data from the first 190 patients (mean age 6 years 10 months (SD 2.0), 111 boys), focusing on physiotherapy, ergotherapy, psychomotility and speech therapy in medico-social and liberal sectors.ResultsIn medico-social sector, duration of paramedical care is significantly more important than in liberal sector (structure of care: median = 4.25 h/week, liberal sector: median = 2.00 h/week) (P < 0.0001). More than 4 different types of care per week are given in medico-social sector, while in liberal sector children benefit from only 2 different types of care a week. In investigators opinion, rehabilitation in structures of care is 71.65% adapted as opposed to 18.75% in the liberal sector (P < 0.001). Children level V have less time of rehabilitation than the others (P = 0.0424).InterpretationRehabilitation of children with cerebral palsy who are not able to walk, with an objective to improve quality of life, is truly multidisciplinary and suitable in medico-social sector.     

(Re)organisation of the somatosensory system after early brain lesion: A lateralization index fMRI study

ObjectiveTo evaluate the relationship between neural (re)organization of the somatosensory cortex and impairment of sensory function (2-point discrimination [2PD]) in individuals with unilateral cerebral palsy.MethodsWe included 21 individuals with unilateral cerebral palsy. 2PD thresholds were evaluated on thumb pads, and activation of the somatosensory cortex was recorded by functional MRI (fMRI) during passive movements of the affected hand. A lateralization index (LI) was calculated for the primary sensory (S1) and secondary sensory (S2) cortices and the correlation between the LI and 2PD thresholds was analysed.ResultsWe found a significant negative correlation between the 2PD thresholds and the S2 LI (r = −0.5, one-tailed P-value = 0.01) and a trend towards a negative correlation with the S1 LI (r = −0.4, one-tailed P-value = 0.05).ConclusionHigh levels of activation in the contralesional hemisphere were associated with high levels of sensory impairment in individuals with unilateral cerebral palsy. The interhemispheric (re)organization of the somatosensory system may not effectively compensate for somatosensory impairment.     

De novo generation in an in vivo rat model and biomechanical characterization of autologous transplants for ligament and tendon reconstruction

BackgroundSurgical reconstruction of ligaments and tendons is frequently required in clinical practice. The commonly used autografts, allografts, or synthetic transplants present limitations in terms of availability, biocompatibility, cost, and mechanical properties that tissue bioengineering aims to overcome. It classically combines an exogenous extracellular matrix with cells, but this approach remains complex and expensive. Using a rat model, we tested a new bioengineering strategy for the in vivo and de novo generation of autologous grafts without the addition of extracellular matrix or cells, and analyzed their biomechanical and structural properties.MethodsA silicone perforated tubular implant (PTI) was designed and implanted in the spine of male Wistar rats to generate neo-transplants. The tensile load to failure, stiffness, Young modulus, and ultrastructure of the generated tissue were determined at 6 and 12 weeks after surgery. The feasibility of using the transplant that was generated in the spine as an autograft for reconstruction of medial collateral ligaments (MCL) and Achilles tendons was also tested.FindingsUse of the PTI resulted in de novo transplant generation. Their median load to failure and Young modulus increased between 6 and 12 weeks (respectively 12 N vs 34 N and 48 MPa vs 178 MPa). At 12 weeks, the neo-transplants exhibited collagen bundles (mainly type III) parallel to their longitudinal axis and elongated fibroblasts. Six weeks after their transfer to replace the MCL or the Achilles tendon, the transplants were still present, with their ends healed at their insertion point.InterpretationThis animal study is a first step in the design and validation of a new bioengineering strategy to develop autologous transplants for ligament and tendon reconstructions.     

Mid-term functional outcome of a total arthroplasty of the first metatarsophalangeal joint

BackgroundArthroplasty of the first metatarsophalangeal joint is an alternative treatment option for end-stage hallux rigidus to the current gold standard of arthrodesis. The aim of this study was to investigate the mid-term functional outcome of an anatomically shaped prosthesis for the first metatarsophalangeal joint using pedobarography.MethodsTen patients (12 affected feet; age at surgery: 62.1 (SD: 7.2) years) were investigated preoperatively and 52 (SD: 3) months postoperatively using pedobarography (EMED, novel GmbH, Munich, Germany). Two patients were excluded at follow-up because their prosthesis was converted to an arthrodesis. Peak force and plantar pressure under the five metatarsal heads and the hallux were analyzed and correlated with the clinical outcome (pain, American Orthopaedic Foot and Ankle Society forefoot score and radiographic maximum first metatarsophalangeal dorsiflexion). Differences between pre- and postoperative data were analyzed using paired t-tests (alpha = 0.05).FindingsPostoperatively, forefoot peak forces under the fourth (+ 40.9%; P = 0.018) and fifth metatarsal (+ 54.9%; P = 0.037) and plantar pressures under the fifth metatarsal (+ 38.7%; P = 0.027) increased significantly, while peak plantar pressures and forces under the hindfoot, medial forefoot and hallux did not change. While maximum passive dorsiflexion was not significantly greater at the 4-year follow-up compared to preoperatively, overall greater passive dorsiflexion was associated with higher first metatarsal peak pressure.InterpretationDespite of patients reporting less pain, the functional results indicate an altered and potentially non-physiological postoperative gait pattern with a lateralization of the load during walking, especially in patients with limited passive dorsiflexion.     

Evaluation of the effectiveness of botulinum toxin injections in the lower limb muscles of children with cerebral palsy. Preliminary prospective study of the advantages of ultrasound guidance

ObjectiveThe aim of this study was to evaluate the effectiveness of injecting botulinum toxin A into the lower limbs of children with cerebral palsy, according to age, dose, dilution, injection site and needle placement technique (manual or ultrasound guidance).Materials and methodsAny child with cerebral palsy examined between May 2005 and May 2006 who needed botulinum toxin A injections in the adductor, hamstring, gastrocnemius and/or soleus muscles could be included. Fifty-four (54) children participated in the study, 30 of whom were injected under ultrasound guidance. The pre- and post- toxin evaluations were done through analytical clinical examination and the Gross Motor Function Measure (GMFM-88).ResultsWe found an overall clinical effectiveness for 51% of the children. This effectiveness was significantly higher for children under 6 years old or over 12, especially when the doses were greater than 0.8 UI/kg per muscle of Botox^®, when the injected muscles were hamstrings or gastrocnemius, and when the injections were guided by ultrasound. Dilution had no effect on clinical effectiveness. Function after one month was better for 24% of the children. This functional improvement was significantly better for children under 6 years old with the injections under ultrasound control.ConclusionsThis study confirms that the effectiveness of botulinum toxin injections is higher in younger children, with injected doses higher than 0.8 UI/kg per muscle of Botox^® and injections guided by ultrasound.     

Reproducibility of hand-held ankle dynamometry to measure altered ankle moment-angle characteristics in children with spastic cerebral palsy

BackgroundIn children with spastic cerebral palsy, the range of motion of the ankle joint is often limited. Measurement of range of motion may be hampered by a non-rigid foot deformity. We constructed a hand-held instrument which allows measurements of static ankle angle and moment in children with cerebral palsy while correcting for foot deformity. This study aimed to test the reproducibility of the instrument and to use it for measuring ankle moment-angle characteristics in individual children who are typically developing and children with cerebral palsy.MethodsAnkle angles and moments were measured at five standardized positions in ten children who are typically developing and ten children with cerebral palsy. The intraclass correlation coefficient was calculated for test–retest reliability. For precision, the standard error of measurement and smallest detectable difference were determined. The ankle range of motion and the slope of the moment-angle curve were determined, both towards plantar flexion and dorsiflexion.FindingsThe reproducibility study revealed a high reliability of the dynamometer at 5 repetitions (> 0.97). Precision lies within 5° for angle measurements and within 0.2 Nm for moment measurements. In the children with cerebral palsy, the range of motion towards dorsiflexion was 18° lower and the slope of the moment-angle curve towards dorsiflexion was substantially higher.InterpretationWe developed a hand-held dynamometer which allows reliable and precise measurements of static ankle angle and moment in children with cerebral palsy. The hand-held dynamometer allows corrections of foot deformities and is qualified to reproducibly evaluate moment-angle characteristics in a clinical context.     

Anterolateral ligament reconstruction with autologous grafting: A biomechanical study

BackgroundTo evaluate the reliability of the Iliotibial band compared to gracilis tendon as a graft to be used in anterolateral ligament reconstruction.MethodsGracilis tendon and a strip of Iliotibial band compared were harvested from 8 fresh human cadaveric knees. The gracilis tendon was prepared to obtain a graft of 10 cm in length (Group 1). Iliotibial band compared was prepared to obtain a graft of 10 cm in length and 0.5 cm in width from the middle portion (Group 2). All the specimens were fixed on a servo hydraulic tensile machine with dedicated cryo-clamp. The loading protocol, used to compare the previously published results of ultimate failure load and Stiffness of the anterolateral ligament (Group 3), included a cyclic preconditioning between 10 and 25 N at 0.1 Hz for 10 cycles and then a load to failure test at 20 mm/min.FindingsGracilis tendon showed higher Ultimante Failure Load and stiffness when compared to a strip of Iliotibial band.Gracilis tendon and a strip of Iliotibial band compared showed higher Ultimante Failure Load and stiffness when compared with native anterolateral ligament as reported by Kennedy.InterpretationBoth grafts tested in the present studies are suitable for an anatomical anterolateral ligament reconstruction.     

Dynamic EMG of peroneus longus in hemiplegic children with equinovarus

ObjectiveIn hemiplegic children the appearance of equinovarus is correlated with premature electromyography (EMG) activity of the gastrocnemius medialis (GM) prior to initial contact. The goal was to analyze the onset of EMG activation in the GM and, more particularly, the peroneus longus (PL) in cases of equinovarus: is PL activity likewise premature?Material and methodsAs 15 hemiplegic children (age 5 years ± 1.5) with equinovarus walked, their PL and GM EMG activity was being recorded. The latter was normalized in terms of gait cycle percentage (0–100%) and detected through semi-automatic selection with activation threshold set at 20 μV. A paired t-test compared activation onset of the PL versus the GM muscles.ResultsAs regards the healthy limb, activity onset of the GM (+14.55%) and the PL (+19.2%) muscles occurred only during the ST. In cases of equinovarus, activation of the GM (−5.2%) and the PL (−6.1%) occurred during the SW and was premature. For each muscle, comparison between the healthy and the hemiplegic side was highly significant (P < 0.001).ConclusionPremature PL and GM EMG activity preceding initial contact corresponds not to a disorder secondary to imbalance but rather, more probably, to motor command dysfunction. While the PL consequently contributes to equinus deformity, its possible role in varus genesis is less evident. EMG study needs to be completed by comparing PL and tibialis posterior strength while taking foot bone morphology into full account.     

Squat test performance and execution in children with and without cerebral palsy

BackgroundKnowledge on lower extremity strength is imperative to informed decision making for children with cerebral palsy (CP) with mobility problems. However, a functional and clinically feasible test is not available. We aimed to determine whether the squat test is suitable for this purpose by investigating test performance and execution in children with cerebral palsy and typically developing (TD) peers.MethodsSquat test performance, defined by the number of two-legged squats until fatigue (max 20), was assessed in twenty children with bilateral CP (6–19 years; gross motor function classification system I–III) and sixteen TD children (7–16 years). Muscle fatigue was assessed from changes in electromyography (EMG). Joint range-of-motion and net torque were calculated for each single squat, to investigate differences between groups and between the 2nd and last squat.FindingsFifteen children with CP performed < 20 squats (median = 13, IQR = 7–19), while all TD children performed the maximum of 20 squats. Median EMG frequency decreased and amplitude increased in mm. quadriceps of both groups. Ankle and knee range-of-motion were reduced in children with CP during a single squat by 10 to 15°. No differences between 2nd and last squat were observed, except for knee range-of-motion which increased in TD children and decreased in children with CP.InterpretationSquat test performance was reduced in children with CP, especially in those with more severe CP. Muscle fatigue was present in both children with CP and TD peers, confirming that endurance of the lower extremity was tested. Minor execution differences between groups suggest that standardized execution is important to avoid compensation strategies. It is concluded that the squat test is feasible to test lower extremity strength in children with CP in a clinically meaningful way. Further clinimetric evaluation is needed before clinical implementation.     

Assessment of bimanual performance in 3-D movement analysis: Validation of a new clinical protocol in children with unilateral cerebral palsy

BackgroundThe “Be an Airplane Pilot” (BE-API) protocol is a novel 3-D movement analysis (3DMA) protocol assessing the bimanual performance of children during a game.ObjectiveThis study aimed to investigate the reliability and validity of this protocol in children with unilateral cerebral palsy (uCP).MethodsAngular waveforms (WAVE), maximum angles (MAX) and range of motion (ROM) of the trunk, shoulder, elbow and wrist joints were collected in children with uCP and in typically developing children (TDC) during 4 tasks of the BE-API protocol designed to explore specific degrees of freedom (DoF). The inter-trial reliability for children with uCP was assessed with the coefficient of multiple correlation (CMC) for WAVE and the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) for MAX and ROM. Clinical performance-based measures, including the Assisting Hand Assessment (AHA) and ABILHAND-Kids scores, were used to explore correlations between clinical measures and kinematic parameters in children with uCP.Results20 children with uCP (13 boys; mean age 12.0 [SD 3.2] years) and 20 TDC (11 boys; mean age 11.9 [SD 3.4] years) were included. In children with uCP, most kinematic parameters showed high reliability (WAVE: CMC ≥ 0.82; MAX and ROM: ICC ≥ 0.85, SEM ≤ 4.7°). Elbow extension, forearm supination, and wrist adduction were reduced and wrist flexion was increased for children with uCP versus TDC (P < 0.01). In children with uCP, MAX and ROM values were moderately correlated with clinical assessments (AHA score: r = 0.48–0.65; ABILHAND-Kids score: r = 0.48–0.49).ConclusionsThe BE-API protocol is a 3DMA-bimanual performance-based assessment that is highly reliable in children with uCP. Children with uCP and TDC significantly differed in some clinically relevant kinematic parameters. The BE-API is a promising playful tool, helpful for better understanding upper-limb motor movement abnormalities in bimanual conditions and for tailoring treatments to individual deficits.     

Delineation of the mechanisms of tendon gliding resistance within the carpal tunnel

BackgroundForceful, high-velocity, and repetitive manual hand tasks contribute to the onset of carpal tunnel syndrome. This study aimed to isolate and identify mechanisms that contribute to tendon gliding resistance in the carpal tunnel.MethodsEight human cadaver hands (four pairs) were used. Tendon gliding resistance (force, energy, and stiffness) was measured under different conditions: with intact and with divided subsynovial connective tissue, at 2 mm/s and 60 mm/s tendon excursion velocity, and with and without relaxation time before tendon excursion.ResultsSubsynovial connective tissue stretching substantially contributed to increased gliding resistance force and energy during higher tendon excursion velocities, and subsynovial connective tissue stiffening was observed. Poroelastic properties of the tendon (and possibly the subsynovial connective tissue) also appear to be involved because relaxation time significantly increased gliding resistance force and energy (P < 0.01), and the difference in energy and force between high- and low-velocity tendon excursions increased with relaxation time (P = 0.01 and P < 0.01). Lastly, without relaxation time, no difference in force and energy was observed (P = 0.06 and P = 0.60), suggesting contact friction.InterpretationThese findings are consistent with the hypothesis that the mechanics of tendon motion within the carpal tunnel are affected by the integrity of the subsynovial connective tissue. While not tested here, in carpal tunnel syndrome this tissue is known to be the fibrotic, thickened, and less-fluid-permeable. An extrapolation of our findings suggests that these changes in the subsynovial connective tissue of carpal tunnel syndrome patients could increase contact friction and carpal tunnel pressure.     

Effect of chronic stretching interventions on the mechanical properties of muscles in patients with stroke: A systematic review

BackgroundMuscle contractures are common after stroke and their treatment usually involves stretching. However, recent meta-analyses concluded that stretching does not increase passive joint amplitudes in patients with stroke. The effectiveness of treatment is usually evaluated by measuring range of motion alone; however, assessing the effects of stretching on the structural and mechanical properties of muscle by evaluating the torque-angle relationship can help in understanding the effects of stretching. Although several studies have evaluated this, the effects remain unclear.ObjectiveA systematic review of the literature on the effectiveness of stretching procedures for which the outcomes included a measurement of torque associated with range of motion or muscle structure (e.g., fascicle length) in stroke survivors.MethodsPubMed, ScienceDirect and PEDro databases were searched by 2 independent reviewers for relevant studies on the effects of chronic stretching interventions (> 4 weeks) that evaluated joint angle and passive torque or muscle structure or stiffness. The quality of the studies was assessed with the PEDro scale.ResultsEight randomized clinical trials (total of 290 participants) met the inclusion criteria, with highly variable sample characteristics (at risk/existing contractures), program objectives (prevent/treat contractures) and duration (from 4 to 52 weeks) and volume of stretching (1 to 586 hr). All studies were classified as high quality (> 6/10 PEDro score). Six studies focused on the upper limb. Many programs were less than 12 weeks (n = 7 studies) and did not change mechanical/structural properties. The longest intervention (52 weeks) increased muscle fascicle length and thickness (plantar flexors).ConclusionLong interventions involving high stretching volumes and/or loads may have effects on muscle/joint mechanical properties, for preventing/treating contractures after stroke injury, but need to be further explored before firm conclusions are drawn.