Postural control strategy after incomplete spinal cord injury: effect of sensory inputs on trunk–leg movement coordination

Stiff-Knee gait (SKG) after stroke is often accompanied by decreased knee flexion angle during the swing phase. The decreased knee flexion has been hypothesized to originate from excessive quadriceps activation. However, it is unclear whether hyperreflexia plays a role in this activation. The goal of this study was to establish the relationship between quadriceps hyperreflexia and knee flexion angle during walking in post-stroke SKG. The rectus femoris (RF) H-reflex was recorded in 10 participants with post-stroke SKG and 10 healthy controls during standing and walking at the pre-swing phase. In order to attribute the pathological neuromodulation to quadriceps muscle hyperreflexia and activation, healthy individuals voluntarily increased quadriceps activity using electromyographic (EMG) feedback during standing and pre-swing upon RF H-reflex elicitation. We observed a negative correlation (R = − 0.92, p = 0.001) between knee flexion angle and RF H-reflex amplitude in post-stroke SKG. In contrast, H-reflex amplitude in healthy individuals in presence (R = 0.47, p = 0.23) or absence (R = − 0.17, p = 0.46) of increased RF muscle activity was not correlated with knee flexion angle. We observed a body position-dependent RF H-reflex modulation between standing and walking in healthy individuals with voluntarily increased RF activity (d = 2.86, p = 0.007), but such modulation was absent post-stroke (d = 0.73, p = 0.296). RF reflex modulation is impaired in post-stroke SKG. The strong correlation between RF hyperreflexia and knee flexion angle indicates a possible regulatory role of spinal reflex excitability in post-stroke SKG. Interventions targeting quadriceps hyperreflexia could help elucidate the causal role of hyperreflexia on knee joint function in post-stroke SKG.     

Arthrogenic muscle inhibition is not present in the limb contralateral to a simulated knee joint effusion

OBJECTIVE: The purpose of this investigation was to estimate bilateral neuromuscular activity in the vastus medialis on induction of a unilateral knee joint effusion. DESIGN: Eight subjects each were assigned to effusion or control groups. The effusion group had 60 ml of sterile saline injected into their superolateral knee joint capsules. The control group rested for 8 mins. Bilateral recruitment curves for the Hoffmann reflex (H-reflex) and muscle response (M-wave) were obtained before and 10, 20, and 30 mins after the effusion or rest. The maximum H-reflex (Hmax), maximum M-wave (Mmax), and the Hmax/Mmax ratio were utilized for data analysis. RESULTS: Both Hmax and Hmax/Mmax ratios decreased from the baseline measure in the effused vastus medialis, whereas no changes were detected on the contralateral side. Effused subjects demonstrated decreased motoneuron pool excitability in the effused limb, whereas control subjects did not differ from baseline. CONCLUSIONS: Knee joint effusion results in ipsilateral but not contralateral impairment of quadriceps function. Rehabilitation protocols after knee joint injury should focus on ipsilateral neuromuscular and mechanical alterations that occur as the result of joint damage.     

Comparison of tibial nerve H-reflex excitability after cervical and lumbar spine manipulation

BACKGROUND: Previous investigations indicate that spinal manipulation leads to short-term attenuation of alpha-motoneuron excitability, when assessed by means of the Hoffmann reflex. Past studies, however, are limited to regional effects, such as lumbar manipulation effects on lumbar alpha-motoneuron activity. OBJECTIVE: This study compared and contrasted the effects of cervical and lumbar spine manipulation on the excitability of the lumbar alpha-motoneuronal pool in human subjects without low back pain, and compared the effects of cervical (nonregional) and lumbar (regional) spinal manipulation on lumbar alpha-motoneuron pool excitability in healthy subjects. The specific aim of this study was to determine if the inhibitory effects on the lumbar alpha-motoneuron pool associated with spinal manipulation are limited to the specific region in which the manipulative procedure is applied, or if rostral (cervical) manipulation can also influence caudal (lumbar) motoneuron excitability. METHOD: Thirty-six nonpatient human subjects were used to study the effect of cervical and lumbar spinal manipulation on the amplitude of the tibial nerve Hoffmann reflex, recorded from the gastrocnemius muscle. The Hoffmann reflex (H-reflex) technique allows for an indirect index of motoneuron pool excitability by means of peripheral nerve Ia-afferent fiber stimulation. Reflexes were recorded before and after spinal manipulative procedures. RESULTS: Lumbar spinal manipulation, as measured by amplitude changes of the tibial nerve H-reflex, attenuated lumbar alpha-motoneuronal activity. Suppression of motoneuronal excitability was significant (P <.05) but transient, with a return to baseline within 60 seconds after manipulation. Cervical spinal manipulation had no significant effect on lumbar motoneuron activity. CONCLUSION: These data indicate that the inhibitory effects of spinal manipulation on motoneuronal excitability are regional, rather than global.     

Spinal Reflex Arc Excitability Corresponding to the Vastus Medialis Obliquus and Vastus Medialis Longus Muscles

[Purpose] The gross morphology of the vastus medialis (VM) muscle has been thoroughly described. However, there is insufficient evidence of physiological differentiation between the VM obliquus (VMO) and VM longus (VML). To elucidate spinal reflex arc excitability in two divisions of the VM, we compared H-reflexes and T-waves in VMO and VML. [Subjects] Twenty-three healthy male volunteers participated in this study. [Methods] The H-reflex was evoked from the VMO and VML by electrical stimulation of the femoral nerve during knee extension at 10% maximal voluntary isometric contraction. Also, the patellar tendon was tapped by an examiner using an electrical tendon hammer, and a component of the compound muscle action potential (T-wave) was recorded. [Results] The configurations of the H-reflex and T-wave were sharp and slow in VMO and VML, respectively. No significant differences in the amplitudes of the H-reflexes and T-waves were observed between VMO and VML. The durations of VML H-reflexes and T-waves were significantly longer than those in VMO. [Conclusion] Spinal reflex arc excitability corresponding to VMO and VML was similar. However, the configurations and durations of the H-reflex and T-wave were differentiated with electromyography. On the basis of these findings, we suggest that VMO and VML are electrophysiologically distinct entities.Key words: Vastus medialis, H-reflex, T-wave     

Reflex actions of knee joint afferents during contraction of the human quadriceps

• 1 The spinal reflex actions of afferents stimulated by knee joint distension have been investigated in man.
• 2 Cannulation of the knee and infusion of saline raised intra-articular pressure, especially during quadriceps contraction. High pressures did not induce any sensation of pain. Pressure was taken as an index of joint proprioceptor activation.
• 3 Increased pressure progressively depressed the quadriceps H-reflex, both at rest and during quadriceps contraction. There was no indication of a threshold pressure for this inhibitory action.
• 4 It is concluded that joint distension inhibits quadriceps motoneurons through spinal pathways that still operate during voluntary contraction. These pathways could thus contribute to pathological weakness after joint injury.
• 5 Joint distension produced spatial facilitation of non-reciprocal inhibition of quadriceps H-reflexes from afferents in the tibia1 nerve.

     

Effects of lumbopelvic joint manipulation on quadriceps activation and strength in healthy individuals

Lumbopelvic joint manipulation has been shown to increase quadriceps force output and activation, but the duration of effect is unknown. It is also unknown whether lower grade joint mobilisations may have a similar effect. Forty-two healthy volunteers (x+/-SD; age=28.3+/-7.3 yr; ht=172.8+/-9.8 cm; mass=76.6+/-21.7 kg) were randomly assigned to one of three groups (lumbopelvic joint manipulation, 1 min lumbar passive range of motion (PROM), or prone extension on elbows for 3 min). Quadriceps force and activation were measured using the burst-superimposition technique during a seated isometric knee extension task before and at 0, 20, 40, and 60 min following intervention. Collectively, all groups demonstrated a significant decrease (p<0.001) in quadriceps force output without changes in activation (p>0.05) at all time intervals following intervention. The group that received a lumbopelvic joint manipulation demonstrated a significant increase in quadriceps force (3%) and activation (5%) (p<0.05) immediately following intervention, but this effect was not present after the 20 min interval. Since participants in this study were free of knee joint pathology, it is possible that they did not have the capacity to allow for large changes in quadriceps muscle activation to occur.     

The effect of transcutaneous electrical stimulation on spinal motor neuron excitability in people without known neuromuscular diseases: the roles of stimulus intensity and location

BACKGROUND AND PURPOSE: The Hoffmann reflex (H-reflex) is widely acknowledged as an indirect indicator of spinal motor neuron excitability. The purpose of this study was to determine whether transcutaneous electrical stimulation (TES), applied over the dorsiflexors or plantar flexors of the ankle, would alter the soleus muscle's H-reflex. Attention was focused on the roles of stimulus intensity and location. SUBJECTS: Thirty-two volunteers without known neuromuscular diseases (17 women [53%]; mean years of age=27, SD=7.3, range=21-48) were studied. METHODS: Subjects were randomly assigned to 1 of 4 groups, and TES was administered for 15 minutes. Stimulation site and intensity varied according to group assignment. H-reflexes were recorded before and for 10 minutes after TES. RESULTS: H-reflex amplitudes increased following TES at sensory threshold, whereas H-reflex amplitudes did not change following TES at 1.5 times motor threshold. The site of stimulation did not influence the resulting H-reflexes. DISCUSSION AND CONCLUSION: Low-intensity TES increases H-reflex amplitudes (and presumably the excitability of spinal motor neurons to Ia afferent input) in subjects without known neuromuscular diseases. High-intensity TES had little influence on H-reflex amplitudes.     

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis

BackgroundNeuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies.ObjectivesThis systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA.MethodsModerate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri?articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps.ResultsA total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus.ConclusionsNeuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men.Prospero registration numberCRD42019160845.     

Changes in soleus motoneuron pool excitability after artificial knee joint effusion

OBJECTIVE: To compare changes in the magnitude of soleus motoneuron excitability before and over a 4-hour period following artificial knee effusion. DESIGN: Before-after trial. SETTING: All measurements were collected in the Sports Injury Research Laboratory, Indiana State University. PARTICIPANTS: Eleven healthy and neurologically sound volunteers (mean age +/- SD, 24 +/- 3yr; height, 173.2 +/- 9.6cm; weight, 72.9 +/- 8.7kg) with no history of lower-extremity surgery and no lower extremity pathology in the last year. INTERVENTIONS: An area superolateral to the patella was cleaned and injected subcutaneously with 2mL of lidocaine for anesthetic purposes. With a second disposable syringe, 25mL of sterile saline was injected through the superolateral knee joint capsule into the joint space to mimic mechanical joint effusion. MAIN OUTCOME MEASURE: Hoffmann's reflex (H-reflex) was elicited by applying a percutaneous stimulus to the tibial nerve in the popliteal fossa. Seven to 12 stimuli were delivered at 20-second intervals with varying intensities to find the maximal H-reflex. The maximal H-reflex was measured five times at the same stimulus intensity with 20-second rest intervals. This measurement was recorded before injection and at 1-hour intervals following the injection for 4 hours. RESULTS: An overall difference between groups was found. Measurements from hours 3 and 4 were significantly higher than the preinjection measurements (p < or = .05). CONCLUSIONS: The soleus motoneuron pool was not inhibited as expected. The soleus was facilitated beyond the preinjection level, showing that the quadriceps and soleus do not respond in the same way to artificial knee effusion. Because the quadriceps are normally inhibited during knee effusion, this facilitation could be the result of a compensatory reaction by the soleus in response to inhibited quadriceps. Further studies must be performed to determine the extent and duration of soleus motoneuron pool excitability in relation to quadriceps inhibition elicited by artificial knee effusion.     

Effect of manual therapy techniques on the stretch reflex in normal human quadriceps

The effect of four manual therapy techniques on the quadriceps stretch reflex amplitude (elicited by mechanical vibration) was studied in a randomized, controlled trial in 120 (20 in each of six groups) healthy human subjects aged 18–64 years. Passive and active techniques were studied; each under static and dynamic conditions. The passive procedures were massage (static) and knee oscillation (dynamic) for 5 min. Active techniques involved eight repetitions of isometric quadriceps contractions (static) and leg extension (dynamic). The two static techniques had no effect on the stretch reflex amplitude. Both dynamic techniques caused a reduction (active by 25%, p < 000001 and passive 12%, p < 005). Only the active, dynamic technique caused a greater change than in the control group (p < 0005). The effect lasted for less than 1 min. These data question the ability of such techniques to make clinically valid changes in motoneuron excitability. Further studies are required on those with neuromuscular pathology, who may respond differently to normal subjects.     

Quadriceps tendinopathy — a forgotten pathology for physiotherapists? A systematic review of the current evidence-base

Abstract

Background: The evidence-base surrounding the pathophysiology and management of specific tendinopathies has evolved over the past 20 years. Recent research examining lower limb tendinopathies has focussed primarily on Achilles and patellar tendon injuries. However, on further examination of the different types of patella/knee tendinopathies, confusion has arisen surrounding the diagnosis and management of patellar compared to quadriceps tendinopathy.

Objectives: The purpose of this paper was to critically examine the evidence-base surrounding the diagnosis and management of quadriceps tendinopathy.

Methods: A systematic literature search of published and unpublished literature databases was conducted to identify literature pertaining to quadriceps tendinopathy. Data from each paper were extracted to examine four key areas related to quadriceps tendinopathy: nomenclature, prevalence, assessment, and management.

Results: Twelve studies satisfied the eligibility criteria and were included in the review. On analysis, little literature has been published solely informing clinicians on the pathology, diagnosis, or management of quadriceps tendinopathy. The terms patellar tendinopathy and jumper’s knee have been incorrectly used interchangeably with quadriceps tendinopathy. Activities such as repetitive squatting and prolonged knee flexion have been associated with the development of this tendinopathy. Sports such as football and volleyball have been cited as causative factors. Quadriceps tendinopathy’s principal diagnostic feature is pain on palpation of the quadriceps/patella interface, and resisted knee extension with the knee hyperflexed. There are no clear recommendations on how to specifically treat quadriceps tendinopathy.

Conclusion: Quadriceps tendinopathy is less commn than patellar tendinopathy. Possibly as a result of this, little is known about how to assess and manage this particular knee tendinopathy. Further research is required to determine the optimal management strategy for patients diagnosed with quadriceps tendinopathy, acknowledging the biomechanical and anatomical difference of the quadriceps compared to the patellar tendon.     

H-reflex modulation during manual muscle massage of human triceps surae

An investigation of the effect of a six-minute manual muscle massage on the excitability of the spinal reflex pathway in 20 able-bodied subjects was undertaken. H-reflex recordings were obtained from the right soleus muscle, which was the site being massaged. Skin temperature and antagonist activity were monitored in an attempt to explain the changes observed in a previous study. The experimental paradigm chosen was an A-B-A interrupted-time series design consisting of two pretreatment, two treatment (massage), and two posttreatment conditions. H-reflex amplitudes recorded during both massage conditions (.76 +/- .58 mV, .76 +/- .61 mV) were significantly reduced (F5,90 = 69.04, p less than .01) in comparison to all other (before and after) conditions (2.58 +/- .75 mV, 2.56 +/- .71 mV, 2.82 +/- 1.14 mV, and 2.89 +/- .82 mV, respectively). This decrease could not be explained conclusively by changes in skin temperature, nerve conduction velocity, or antagonist recruitment, thus indicating a decrease in spinal reflex excitability attributed to massage. These findings also support our earlier report, which stated that H-reflex amplitudes are reduced only during the period of tissue manipulation, regardless of the duration of the massage.     

Superior-inferior position of patellar component affects patellofemoral kinematics and contact forces in computer simulation

BackgroundAnterior knee pain has been reported as a major postoperative complication after total knee arthroplasty, which may lead to patient dissatisfaction. Rotational alignment and the medial-lateral position correlate with patellar maltracking, which can cause knee pain postoperatively. However, the superior-inferior position of the patellar component has not been investigated. The purpose of the current study was to investigate the effects of the patellar superior-inferior position on patellofemoral kinematics and kinetics.MethodsSuperior, central, and inferior models with a dome patellar component were constructed. In the superior and inferior models, the position of the patellar component translated superiorly and inferiorly, respectively, by 3 mm, relative to the center model. Kinematics of the patellar component, quadriceps force, and patellofemoral contact force were calculated using a computer simulation during a squatting activity in a weight-bearing deep knee bend.FindingsIn the inferior model, the flexion angle, relative to the tibial component, was the greatest among all models. The inferior model showed an 18.0%, 36.5%, and 22.7% increase in the maximum quadriceps force, the maximum medial patellofemoral force, and the maximum lateral patellofemoral force, respectively, compared with the superior model.InterpretationSuperior-inferior positions affected patellofemoral kinematic and kinetics. Surgeons should avoid the inferior position of the patellar component, because the inferior positioned model showed greater quadriceps and patellofemoral force, resulting in a potential risk for anterior knee pain and component loosening.     

Effectiveness of manual therapy in the treatment of non-specific neck pain: a review

Abstract

The aim of the current review was to assess the evidence for the effectiveness of cervical spine manipulation and mobilisation in the treatment of non-specific neck pain. A review of the literature was performed in a systematic format, based upon a structured search of six computerised bibliographic databases, together with manual searching of selected journals and reference lists to identify randomised clinical trials (RCTs) researching the effectiveness of manual therapy in the treatment of non-specific neck pain. The methodological quality of the studies was assessed using a set of pre-defined criteria adapted from Koes et al. (Koes BW, Assendelft WJJ, van der Heijden GJMG, Bouter LM, Knipschild PG. Spinal manipulation and mobilisation for back and neck pain: a blinded review. BMJ 1991; 303 :1298–303) and updated in the light of recent literature.

A total of 12 RCTs met the selection criteria. The scores achieved for methodological quality of the studies ranged from 25 points to 67 points out of a possible 100 points. Only four RCTs scored above 50 points: two of these reached a positive conclusion about the effectiveness of spinal manual therapy in the treatment of non-specific neck pain, and two a negative conclusion. Eight RCTs scored below 50 points; six of these reached a positive conclusion and two a negative conclusion.

RCTs researching the effectiveness of manual therapy for non-specific neck pain demonstrate methodological shortcomings in both design and reporting. The effectiveness of spinal manual therapy on non-specific neck pain remains inconclusive. The available evidence favoured spinal manual therapy when it was used in conjunction with exercise, particularly in the treatment of patients with chronic non-specific neck pain. Further, well-designed RCTs are needed to draw valid conclusions about the effectiveness of spinal manual therapy on nonspecific neck pain. In such future RCTs, placebo treatments should be designed to be indistinguishable (as far as possible) from manual therapy, and without the specific effects of active therapy. Furthermore, psychosocial factors should be considered prior to randomisation of patients by using appropriate measures.     

Sacroiliac joint manipulation attenuates alpha-motoneuron activity in healthy women: a quasi-experimental study

Orakifar N, Kamali F, Pirouzi S, Jamshidi F. Sacroiliac joint manipulation attenuates alpha-motoneuron activity in healthy women: a quasi-experimental study.ObjectiveTo determine whether sacroiliac joint (SIJ) manipulation decreases α-motoneuron activity and increases the pressure pain threshold (PPT) over the posterior superior iliac spine (PSIS) in healthy women.DesignQuasi-experimental study.SettingA university medical center.ParticipantsHealthy young women (N=20) aged 18 to 30 years were recruited from among the students of a university medical center after a request for volunteers.InterventionsJoint manipulation consisted of the supine rotational glide manipulation for the sacroiliac region. PPT measurements from the PSIS and Hoffman-reflex (H-reflex) amplitudes from the tibial nerve on the same side were recorded before and after joint manipulation. PPT was monitored for 15 minutes and H-reflex for 20 minutes after the procedure.Main Outcome MeasuresChanges in tibial nerve H-reflex amplitude and PPT values after SIJ manipulation.ResultsSIJ manipulation attenuated α-motoneuronal activity significantly (P<.05) but transiently, since the decrease was seen only for 20 seconds after the intervention. There was no positive significant difference in the PPT after SIJ manipulation at any time during postintervention follow-up.ConclusionsSIJ manipulation produced a transient attenuation of α-motoneuron excitability in healthy women. These findings demonstrate that our manipulation technique can lead to a short-term reduction in muscle tone as a result of changes in sensory discharge, predominantly in la afferents. SIJ manipulation did not significantly affect the PPT in healthy women.     

Reliability of two functional clinical tests to evaluate trunk and lumbopelvic neuromuscular control and proprioception in a healthy population

ObjectivesThe need to accurately assess trunk and lumbopelvic proprioception and neuromuscular control is widely accepted. However, based on current literature, there is a lack of reliable clinical tests to evaluate these aspects in clinical practice. The objective of this study is to investigate intra- and inter-tester reliability of the lateral step down test and the lumbopelvic position–reposition test in a healthy population.MethodsProtocol and scoring methods were developed for the lateral step down test and lumbopelvic position–reposition test, used to assess trunk and lumbopelvic neuromuscular control and proprioception respectively. Each test was performed once by thirty participants and video analysis for test scoring was performed. Three items on the lateral step down test were scored to evaluate neuromuscular control and, four items on the lumbopelvic position–reposition test were scored to evaluate proprioception. Aggregate scores for each test were calculated based on the separate item scores. Intraclass correlation coefficients and linear weighted kappa coefficients were determined for intra- and inter-tester reliability.ResultsBased on the aggregate score, excellent intra- and inter-tester reliability (ICC (2,1) = 0.73–0.88) was found for both tests. Moderate/almost perfect intra-and inter-tester agreement (K = 0.62–0.91) was found for the separate items of the lateral step down test and fair/substantial agreement (K = 0.25–0.76) for the items of the lumbopelvic position–reposition test.ConclusionCurrent testing protocol and scoring method for the lateral step down test is reliable. Adjustments for the scoring method of the lumbopelvic position–reposition test are warranted to improve reliability.     

Comparison of Single Bout Effects of Bicycle Training Versus Locomotor Training on Paired Reflex Depression of the Soleus H-Reflex After Motor Incomplete Spinal Cord Injury

Phadke CP, Flynn SM, Thompson FJ, Behrman AL, Trimble MH, Kukulka CG. Comparison of single bout effects of bicycle training versus locomotor training on paired reflex depression of the soleus H-reflex after motor incomplete spinal cord injury.

Objective

To examine paired reflex depression changes post 20-minute bout each of 2 training environments: stationary bicycle ergometer training (bicycle training) and treadmill with body weight support and manual assistance (locomotor training).

Design

Pretest-posttest repeated-measures.

Setting

Locomotor laboratory.

Participants

Motor incomplete SCI (n=12; mean, 44±16y); noninjured subjects (n=11; mean, 30.8±8.3y).

Intervention

All subjects received each type of training on 2 separate days.

Main Outcome Measure

Paired reflex depression at different interstimulus intervals (10s, 1s, 500ms, 200ms, and 100ms) was measured before and after both types of training.

Results

(1) Depression was significantly less post-SCI compared with noninjured subjects at all interstimulus intervals and (2) post-SCI at 100-millisecond interstimulus interval: reflex depression significantly increased postbicycle training in all SCI subjects and in the chronic and spastic subgroups (P<.05).

Conclusions

Phase-dependent regulation of reflex excitability, essential to normal locomotion, coordinated by pre- and postsynaptic inhibitory processes (convergent action of descending and segmental inputs onto spinal circuits) is impaired post-SCI. Paired reflex depression provides a quantitative assay of inhibitory processes contributing to phase-dependent changes in reflex excitability. Because bicycle training normalized reflex depression, we propose that bicycling may have a potential role in walking rehabilitation, and future studies should examine the long-term effects on subclinical measures of reflex activity and its relationship to functional outcomes.     

Decrease of hypertonia after continuous passive motion treatment in individuals with spinal cord injury

OBJECTIVE: To examine the effect of ankle continuous passive motion on the reflex excitability and overall hypertonia of calf muscles in individuals with chronic spinal cord injury and without physical disabilities. DESIGN: Two-way repeated measure experimental design. SETTING: Inpatient rehabilitation department in general hospital. SUBJECTS: The spinal cord injury group comprised eight individuals with chronic complete spinal cord injury and the control group comprised eight healthy people without physical disabilities. An additional eight healthy people were recruited as the sham group. INTERVENTIONS: Each subject received 60 min of continuous passive motion on the ankle joint. MAIN MEASURES: The H-reflex of the soleus muscle was elicited by tibia nerve stimulation just before, immediately after, and 10 min after continuous passive motion. The Modified Ashworth Scale (MAS) score at the ankle joint was recorded for the spinal cord injury group just before and 10 min after continuous passive motion therapy. RESULTS. After 60 min of continuous passive motion of the ankle joint, the H-reflex amplitude at the soleus muscle was depressed in individuals with and without spinal cord injury (77.46 +/- 32.64%, P = 0.047 and 51.76 +/- 26.74% of initial, P<0.0001, respectively). This depression persisted up to 10 min after continuous passive motion only in individuals without spinal cord injury. In individuals with spinal cord injury, the median of MAS scores decreased from 2 to 1.25 after continuous passive motion. CONCLUSION: Sixty minutes of continuous passive motion of the ankle joint decreased reflex excitability and overall hypertonia in people with or without spinal cord injury. The depression of overall hypertonia persisted longer than the reflex excitability in people with spinal cord injury.     

Narrative: Review of Anterior Knee Pain Differential Diagnosis (Other than Patellofemoral Pain)

Purpose of ReviewThis review presents a framework for constructing a differential diagnosis for chronic anterior knee pain associated with overuse other than patellofemoral pain. Traumatic, systemic, and pediatric injuries will not be covered.Recent FindingsFrom superficial to deep, the anterior knee can be conceptually organized into four layers: (1) soft tissue, (2) extensor mechanism, (3) intracapsular/extrasynovial, and (4) intra-articular.SummaryFrom superficial to deep, diagnoses to consider include bursitis, patellar and quadriceps tendinosis, fat pad impingement, and plica syndromes.