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Anonymous applications free scientists to make bold proposals, and ‘golden tickets’ free reviewers to bet on them, says Thomas Sinkjær. Anonymous applications free scientists to make bold proposals; ‘golden tickets’ free reviewers to bet on them, says Thomas Sinkjær.

In activities of daily living, people walk at different speeds with or without carrying additional loads. In this study, we sought to examine how human adults manage these commonly encountered additional demands during walking. We measured electromyography (EMG), triceps surae H‐reflexes, joint motion and ground reaction forces (GRF) while participants walked at 1.0 m/s and 1.5 m/s with or without an additional 20.4 kg of weight (the equivalent of 23–36% bodyweight). Faster walking was accompanied by a universal increase in burst EMG amplitude across flexors and extensors of upper and lower leg muscles (with most notable increases found in the plantarflexors) while burst patterns of activity were maintained. In addition, the range of motion increased at the ankle, knee and hip joints, while the step cycle duration was shortened. In bearing additional weight, upper and lower leg extensor activity, especially early stance quadriceps activity, was increased while joint motion was minimally affected at the ankle and knee (but not hip). When walking faster and carrying additional weight, changes in locomotor EMG (except for plantarflexors) and knee and hip joint motion displayed combined features of those two additional demands; changes in plantarflexor activity and ankle joint motion were more complex. Locomotor H‐reflexes were larger at 1.5 m/s than at 1.0 m/s only when carrying additional weight. In generating plantarflexor activity and controlling ankle joint motion for propulsive force generation when walking faster and carrying additional weight, multiple mechanisms of both spinal and supraspinal origin may be involved. What is the central question of the study? How do people walk faster and carry additional weight? What is the main finding and its importance? When walking faster, activity increases in ankle and knee flexors and extensors with little change in pattern; mid–late stance ankle extensor increases strikingly. Carrying additional weight increases extensor but not flexor activity. Walking faster while carrying additional weight additively alters knee and hip flexor/extensor activity and knee and hip motion but not ankle extensor activity or H‐reflexes. The findings support the interpretation of combined central and afferent input to shape and drive the spinal locomotor network.

The present paper examines the relation between size, accumulation and performance for research grants, where we examine the relation between grant size for Centres of Excellence (CoE) funded by the Danish National Research Foundation (DNRF) and various ex post research performance measures, including impact and shares of highly cited articles. We examine both the relation between size and performance and also how performance for CoEs evolves over the course of grant periods. In terms of dynamics, it appears that performance over the grant period (i.e. 10 years) is falling for the largest CoEs, while it is increasing for those among the smallest half. Overall, multivariate econometric analysis finds evidence that performance is increasing in grant size and over time. In both cases, the relation appears to be non-linear, suggesting that there is a point at which performance peaks. The CoEs have also been very successful in securing additional funding, which can be viewed as a 'cumulative effect' of center grants. In terms of new personnel, the far majority of additional funding is spent on early career researchers, hence, this accumulation would appear to have a 'generational' dimension, allowing for scientific expertise to be passed on to an increasing number of younger researchers.

Rehabilitation with augmented electrical stimulation can enhance functional recovery after stroke, and cortical plasticity may play a role in this process. The purpose of this study was to compare the effects of three training paradigms on cortical excitability in healthy subjects. Cortical excitability was evaluated by analysing the input–output relationship between transcranial magnetic stimulation intensity and motor evoked potentials (MEPs) from the flexor muscles of the fingers. The study was performed with 25 healthy volunteers who underwent 20-min simulated therapy sessions of: (1) functional electrical stimulation (FES) of the finger flexors and extensors, (2) voluntary movement (VOL) with sensory stimulation, and (3) therapeutic FES (TFES) where the electrical stimulation augmented voluntary activation. TFES training produced a significant increase in MEP magnitude throughout the stimulation range, suggesting an increase in cortical excitability. In contrast, neither the FES nor voluntary movement alone had such an effect. These results suggest that the combination of voluntary effort and FES has greater potential to induce plasticity in the motor cortex and that TFES might be a more effective approach in rehabilitation after stroke than FES or repetitive voluntary training alone.

Anonymous applications free scientists to make bold proposals, and 'golden tickets' free reviewers to bet on them, says Thomas Sinkjær.

In clinical practice, signs of exaggerated tendon tap reflexes associated with muscle hypertonia are generally thought to be responsible for spastic movement disorders. Most antispastic treatments are, therefore, directed at the reduction of reflex activity. In recent years, however, researchers have noticed a discrepancy between spasticity as measured in the clinic and functional spastic movement disorders, which is primarily due to the different roles of reflexes in passive and active states, respectively. We now know that central motor lesions are associated with loss of supraspinal drive and defective use of afferent input with impaired behaviour of short-latency and long-latency reflexes. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fibre, collagen tissue, and tendon properties (eg, loss of sarcomeres, subclinical contractures) result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organisation. Antispastic drugs can accentuate paresis and therefore should be applied with caution in mobile patients.

A constant coordination between the left and right leg is required to maintain stability during human locomotion, especially in a variable environment. The neural mechanisms underlying this interlimb coordination are not yet known. In animals, interneurons located within the spinal cord allow direct communication between the two sides without the need for the involvement of higher centers. These may also exist in humans since sensory feedback elicited by tibial nerve stimulation on one side (ipsilateral) can affect the muscles activation in the opposite side (contralateral), provoking short-latency crossed responses (SLCRs). The current study investigated whether contralateral afferent feedback contributes to the mechanism controlling the SLCR in human gastrocnemius muscle. Surface electromyogram, kinematic and kinetic data were recorded from subjects during normal walking and hybrid walking (with the legs moving in opposite directions). An inverse dynamics model was applied to estimate the gastrocnemius muscle proprioceptors' firing rate. During normal walking, a significant correlation was observed between the magnitude of SLCRs and the estimated muscle spindle secondary afferent activity (P = 0.04). Moreover, estimated spindle secondary afferent and Golgi tendon organ activity were significantly different (P ≤ 0.01) when opposite responses have been observed, that is during normal (facilitation) and hybrid walking (inhibition) conditions. Contralateral sensory feedback, specifically spindle secondary afferents, likely plays a significant role in generating the SLCR. This observation has important implications for our understanding of what future research should be focusing on to optimize locomotor recovery in patient populations.

This paper describes a clinical randomized single-blinded study of the effects of Functional Electrical Therapy (FET) on the paretic arms of subjects with acute hemiplegia caused by strokes. FET is an exercise program that comprises voluntary arm movements and opening, closing, holding, and releasing of objects that are assisted by a neural prosthesis (electrical stimulation). FET consisted of a 30 min everyday exercise for 3 consecutive weeks in addition to conventional therapy. Twenty-eight acute hemiplegic subjects participated in a 6 mo study. The subjects were divided into lower functioning groups (LFGs) and higher functioning groups (HFGs) based on their capacity to voluntarily extend the wrist and fingers against the gravity, and were randomly assigned to controls or FET groups. The outcomes included the Upper Extremity Function Test, the coordination of elbow and shoulder movements, spasticity of key muscles of the paretic arm, and Reduced Upper Extremity Motor Activity Log. FET and control groups showed a recovery trend in all outcome measures. The gains in FET groups were much larger compared with the gains in control groups. The speed of recovery in FET groups was substantially faster compared with the recovery rate in control groups during the first 3 weeks (treatment). The LFG subjects showed less improvement than the HFG in both the FET and control groups.

The aim of this study was to investigate the contribution of proprioceptive feedback to the amplitude modulation of the soleus muscle activity during human walking. We have previously shown that slow-velocity, small-amplitude ankle dorsiflexion enhancements and reductions applied during the stance phase of the step cycle generate, respectively, increments and decrements on the ongoing soleus activity. We have also shown that the increments in soleus activity are at least partially mediated by feedback from group Ia fibres. In the present study, we further investigated the afferent-mediated contribution from muscle group II afferents, cutaneous and proprioceptive afferents from the foot, and load-sensitive afferents to the soleus EMG. Slow-velocity, small-amplitude ankle trajectory modifications were combined with the pharmaceutical depression of group II polysynaptic pathways with tizanidine hydrochloride, anaesthetic blocking of sensory information from the foot with injections of lidocaine hydrochloride, and modulation of load feedback by increasing and decreasing the body load. The depression of the group II afferents significantly reduced the soleus response to the ankle trajectory modifications. Blocking sensory feedback from the foot did not have an effect on the soleus muscle activity. Changes in body load affected the ongoing soleus activity level; however, it did not affect the amplitude of the soleus EMG responses to the ankle trajectory modifications. These results suggest that the feedback from group II afferents, and possibly from load-sensitive afferents, contribute to the amplitude modulation of the soleus muscle activity during the stance phase of the step cycle. However, feedback from cutaneous afferents and instrinsic proprioceptive afferents from the foot does not seem to contribute to this muscle activation.

There are indications that both intensive exercise and electrical stimulation have a beneficial effect on arm function in post-stroke hemiplegic patients. We recommend the use of Functional Electrical Therapy (FET), which combines electrical stimulation of the paretic arm and intensive voluntary movement of the arm to exercise daily functions. FET was applied 30 min daily for 3 weeks. Forty-one acute hemiplegics volunteered in the 18-months single blinded cross-over study (CoS). Nineteen patients (Group A) participated in FET during their acute hemiplegia, and 22 patients (Group B) participated in FET during their chronic phase of hemiplegia. Group B patients were controls during FET in acute hemiplegia, and Group A patients were controls during the FET in chronic hemiplegia. Thirty-two patients completed the study. The outcomes of the Upper Extremity Function Test (UEFT) were used to assess the ability of patients to functionally use objects, as were the Drawing Test (DT) (used to assesse the coordination of the arm), the Modified Ashworth Scale, the range of movement, and the questionnaire estimating the patients' satisfaction with the usage of the paretic arm. Patients who participated in the FET during the acute phase of hemiplegia (Group A) reached functionality of the paretic arm, on average, in less than 6 weeks, and maintained this near-normal use of the arm and hand throughout the follow-up. The gains in all outcome scores were significantly larger in Group A after FET and at all follow-ups compared with the scores before the treatment. The gains in patients who participated in the FET in the chronic phase of hemiplegia (Group B) were measurable, yet not significant. The speed of recovery was larger during the period of the FET compared with the follow-up period. The gains in Group A were significantly larger compared with the gains in Group B. The FET greatly promotes the recovery of the paretic arm if applied during the acute phase of post-stroke hemiplegia.Key words: stroke, hemiplegia, cross-over study, electrical stimulation, intensive exercise.