The valid confirmation of a positive change (improvement) in a patient’s health status due to intervention has been at the core of medicine and rehabilitation since their very inception as clinicians ...always aspired to ensure that treating their patients had led to successful outcomes both in acute and chronic conditions. However what is change: either im-provement or worsening (aggravation), is a complicated issue which involves clinical as well as statistical considerations. Change invariably relates to a difference in some measurable entity and almost always it relates to a time span. The confirmation of clinical change is important both for varying the treatment course (if necessary) and for the termina-tion of treatment when the latter has reached wither its prescribed ob-jective or a plateau. Since in the context of rehabilitation, the outcome measures (OM) are strongly linked to performance, determination of change in the latter is confounded by many factors, collectively known as the error of measurement, which render a decision regarding clini-cally meaningful change, highly involved. This is further complicated by the stability of the observed OM, the so-called reproducibility of the OM, and the accuracy of the measurement instrument. The higher the re-producibility the lower is the error. Moreover, in order to proclaim change, in most cases a positive one, it is necessary for the difference in outcome scores (i.e. the change) to surpass the error of measure-ment, in varying degree of rigor. This paper describes selected methods associated with determination of change and focuses predominantly on the difference between a simple difference in scores (‘simple change’), a significant difference in scores and the so-called clinically meaningful change in scores which is considered today as the bench-mark for confirmation of a real change.
Needless to say, PubMed is one of the world's leading medical resources; it handles millions of queries daily and is an essential tool for health researchers worldwide.3 Since its introduction, its ...effect on public health has been incalculable. Therefore, it is worrisome that PubMed includes journals with seriously flawed peer review processes.
Purpose
Many studies have investigated postural reactions (PR) to body-delivered perturbations. However, attention has been focused on the descriptive variables of the PR rather than on the ...characterization of the perturbation. This study aimed to test the hypothesis that the impulse rather than the force magnitude of the perturbation mostly affects the PR in terms of displacement of the center of foot pressure (ΔCoP).
Methods
Fourteen healthy young adults (7 males and 7 females) received 2 series of 20 perturbations, delivered to the back in the anterior direction, at mid-scapular level, while standing on a force platform. In one series, the perturbations had the same force magnitude (40 N) but different impulse (range: 2–10 Ns). In the other series, the perturbations had the same impulse (5 Ns) but different force magnitude (20–100 N). A simple model of postural control restricted to the sagittal plane was also developed.
Results
The results showed that ΔCoP and impulse were highly correlated (on average:
r
= 0.96), while the correlation ΔCoP–force magnitude was poor (
r
= 0.48) and not statistically significant in most subjects. The normalized response, ΔCoP
n
= ΔCoP/I, was independent of the perturbation magnitude in a wide range of force amplitude and impulse and exhibited good repeatability across different sets of stimuli (on average: ICC = 0.88). These results were confirmed by simulations.
Conclusion
The present findings support the concept that the magnitude of the applied force alone is a poor descriptor of trunk-delivered perturbations and suggest that the impulse should be considered instead.
Upper neck impairments are more prevalent in patients with temporomandibular disorders (TMDs) but the differences between specific types of TMDs are unclear. This study evaluated the distribution of ...such impairments among different forms of TMD. In total, 116 participants (86 women and 30 men, age range 21–75 yr) were investigated. Forty‐two individuals had no TMDs and were assigned to the control group. The remaining 74 patients were assigned to one of three groups based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) findings: pain‐related (n = 37); intra‐articular (n = 17); or mixed (combined pain‐related and intra‐articular) (n = 20). Analyses of impairments included between‐group comparisons of key parameters of upper neck performance (active/passive mobility and muscular capabilities) and pain (subjective neck disability and pain sensitivity). Patients in the pain‐related and mixed TMD groups were found to have decreased upper neck mobility in the cervical flexion‐rotation test compared with patients in intra‐articular and control groups, as well as poorer capabilities of the deep neck flexor muscles in the cranio‐cervical flexion test compared to the control group. It was concluded that patients with pain‐related TMD diagnoses are more likely to experience significant upper‐neck hypomobility and poor muscular capabilities than patients with intra‐articular diagnoses of TMD.
Purpose
Postural reactions (PR) of standing subjects have been mostly investigated in response to platform displacements or body perturbations of fixed magnitude. The objective of this study was to ...investigate the relationship between PR and the peak force and impulse of the perturbation.
Methods
In ten healthy young men, standing balance was challenged by anteriorly directed perturbations (peak force: 20–60 N) delivered to the back, at the lumbar (L) or inter-scapular (IS) level, by means of a manual perturbator equipped with a force sensor. Postural reactions as expressed by the displacement of the center of pressure (CoP) were recorded using a force platform. Two sets of 20 randomly ordered perturbations (10 to each site) were delivered in two separate testing sessions.
Results
The magnitude of CoP response (∆CoP) was better correlated with the impulse (
I
) than with the peak force of the perturbation. The normalized response, ∆CoP
n
= ∆CoP/
I
, exhibited good reliability (ICCs of 0.93 for IS and 0.82 for L), was higher with IS than with L perturbations (
p
< 0.01), and was significantly correlated with the latency of CoP response:
r
= 0.69 and 0.71 for IS and L, respectively.
Conclusion
These preliminary findings support the concept that manually delivered perturbations can be used to reliably assess individual PR and that ∆CoP
n
may effectively express a relevant aspect of postural control.
Purpose
Music listening while running enhances physiological and psychological features, resulting in a more enjoyable experience. The possible influence of music on ground reaction forces (GRF) ...during running, however, is unknown. Considering the ‘distracting’ role of music on runner’s attention, we hypothesized that music would cover foot impacts against the ground. This study verified such hypothesis by testing the effects of different music volumes while running at different velocities.
Methods
Fifty fit volunteers (
F
:
M
= 22:8; 23 ± 2 years) performed 2-min running stints over 3 random conditions (80-dB, 85-dB music; ‘no music’), at 3 velocities (8, 10, 12 km/h). Participants ran on a sensorized treadmill that recorded GRF during all experiments.
Results
Listening to 85-dB music resulted in greater GRF at 8 (
p
= 0.0005) and 10 km/h (
p
= 0.04) but not 12 km/h (
p
= 0.35) and not with 80-dB volume. Gender-based analyses revealed significant Condition × gender interactions only for 85-dB music vs
.
‘no music’. Bonferroni-adjusted comparisons revealed significant music-induced increases in GRF only in men at 8 km/h (+ 4.1 kg/cm
2
,
p
< 0.0005; women: + 0.8 kg/cm
2
,
p
= 0.47) and 10 km/h (+ 3.3 kg/cm
2
,
p
= 0.004; women: + 0.8 kg/cm
2
,
p
= 0.51) but not at 12 km/h.
Conclusion
In active men, listening to loud music while running results in increased GRF, whereas no effect was observed in women. The lack of music effect in women may be related to structural factors, such as larger hip width-to-femoral length ratio, possibly resulting in different loading patterns. The present preliminary findings introduce high-volume music listening as a new potential risk factor for injury in young runners.
BACKGROUND: The high variability in muscle performance, especially in muscle strength, typical of people with multiple sclerosis (PwMS) implies that in order for strength variations to be clinically ...interpretable, the extent of variability should be properly quantified. OBJECTIVE: To establish the responsiveness of maximal isokinetic strength measurements obtained from the ankle dorsiflexors of PwMS and of a cohort of matched healthy controls. METHODS: Twenty PwMS and 20 healthy controls participated in this study. All subjects underwent a dedicated familiarization session and then three isokinetic testing sessions (Test 1; 1-day retest; 1-week retest) in which the peak moment (PM) and maximal work (MW) were recorded in the more affected side. RESULTS: PwMS proved significantly weaker than controls (p< 0.00005). The test-retest consistency of the measurements proved high for both groups (all intraclass correlation coefficients > 0.9). Importantly, the smallest real difference (SRD) scores ranged 11.4–19.8% for PwMS and 9.2–14.4% for controls. CONCLUSIONS: The responsiveness of the strength and work findings in this cohort indicates that isokinetic measurements of dorsiflexion performance in PwMS may effectively be employed for detecting the efficiency of an intervention in spite of the fluctuating nature of this disease.
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