Efficacy of self-administered complex decongestive therapy on breast cancer-related lymphedema: a single-blind randomized controlled trial.

PURPOSE: After surgery, breast cancer-related lymphedema (BCRL) is a frequent chronic condition. The complex decongestive therapy (CDT) delivered by physiotherapists at hospitals is the state-of-the-art treatment choice. As lymphedema requires continuous management, we designed a 1-month-long course to train women to professionally carry out a self-administered CDT (saCDT) and tested its efficacy while keeping the benefits of CDT. METHODS: Consecutive patients treated with CDT over a 1-year period at an Italian facility were randomly assigned to either experimental (EXP, saCDT course) or control (CTRL, usual care) group. Women were assessed before, at 1, and 6 months from enrolment. Pain assessed by the numerical pain rating scale (NPRS) was the primary outcome. Arm asymmetry assessed by the excess limb volume (ELV) was the secondary outcome. Outcome variations were compared to their MCID to classify women as improved, stable, or worsened. RESULTS: Forty-one women were included. The proportion of stable or improved women was significantly different between EXP and CTRL groups at 6 months after enrolment for both arm pain (p = 0.01) and asymmetry (p < 0.01). Noteworthy, only one EXP woman had worsened after 6 months. NPRS significantly decreased in the EXP group only, with a median variation of 2 points. Arm ELV significantly decreased with respect to the baseline value in the EXP group only, with a median reduction of 8%. CONCLUSIONS: Teaching saCDT to women with BCRL is effective in maintaining or improving the benefits of CDT and can be used as a self-care tool in the management of BCRL.

A statistical approach to discriminate between non-fallers, rare fallers and frequent fallers in older adults based on posturographic data.

BACKGROUND: Identification of future non-fallers, infrequent and frequent fallers among older people would permit focusing the delivery of prevention programs on selected individuals. Posturographic parameters have been proven to differentiate between non-fallers and frequent fallers, but not between the first group and infrequent fallers. METHODS: In this study, postural stability with eyes open and closed on both a firm and a compliant surface and while performing a cognitive task was assessed in a consecutive sample of 130 cognitively able elderly, mean age 77(7)years, categorized as non-fallers (N=67), infrequent fallers (one/two falls, N=45) and frequent fallers (more than two falls, N=18) according to their last year fall history. Principal Component Analysis was used to select the most significant features from a set of 17posturographic parameters. Next, variables derived from principal component analysis were used to test, in each task, group differences between the three groups. FINDINGS: One parameter based on a combination of a set of Centre of Pressure anterior-posterior variables obtained from the eyes-open on a compliant surface task was statistically different among all groups, thus distinguishing infrequent fallers from both non-fallers (P<0.05) and frequent fallers (P<0.05). INTERPRETATION: For the first time, a method based on posturographic data to retrospectively discriminate infrequent fallers was obtained. The joint use of both the eyes-open on a compliant surface condition and this new parameter could be used, in a future study, to improve the performance of protocols and to verify the ability of this method to identify new-fallers in elderly without cognitive impairment.

Assessment of waveform similarity in clinical gait data: the linear fit method.

The assessment of waveform similarity is a crucial issue in gait analysis for the comparison of kinematic or kinetic patterns with reference data. A typical scenario is in fact the comparison of a patient's gait pattern with a relevant physiological pattern. This study aims to propose and validate a simple method for the assessment of waveform similarity in terms of shape, amplitude, and offset. The method relies on the interpretation of these three parameters, obtained through a linear fit applied to the two data sets under comparison plotted one against the other after time normalization. The validity of this linear fit method was tested in terms of appropriateness (comparing real gait data of 34 patients with cerebrovascular accident with those of 15 healthy subjects), reliability, sensitivity, and specificity (applying a cluster analysis on the real data). Results showed for this method good appropriateness, 94.1% of sensitivity, 93.3% of specificity, and good reliability. The LFM resulted in a simple method suitable for analysing the waveform similarity in clinical gait analysis.

A method to differentiate the causes of stiff-knee gait in stroke patients.

Stiff-knee gait (SKG) is a common abnormal gait pattern in patients after stroke characterized by insufficient knee flexion (KF) during swing. Overactivity of the rectus femoris (RF) is considered the primary cause of SKG. Inadequate push-off has been indicated as an additional cause in the recent literature, as KF depends on knee flexion velocity in preswing (KFV). We used the peak of vertical acceleration of the malleolus (PMVA) as a kinematic-based indirect measure of push-off and studied its relationship with KF and KFV in a sample of 20 healthy subjects walking fast (v = 95 ± 5%heights(-1)), at self-selected speed (v = 74 ± 5%heights(-1)), slow (v = 54 ± 6%heights(-1)) and very slow (v = 38 ± 5%heights(-1)) and in a sample of 52 stroke patients with SKG (age 60 ± 11, v = 20 ± 11%heights(-1)). In healthy subjects PMVA occurred before knee flexion acceleration (p<0.001) and hip flexion acceleration (p<0.001). KF appeared as a bottom-up mechanism driven by the ankle push-off. From a regression analysis, the PMVA-KFV cause-effect relationship resulted strictly linear, with R(2) = 0.967, KFV = 0+7.1×PMVA, P<0.0001. Data from SKG patients were compared to this normal cause-effect model. For 44/52 patients the reduced KFV was combined with lack of push-off. Data from 8/52 patients only were statistically outside the 95%CI of the model, thus requiring for a braking mechanism to explain KFV reduction. In stroke adults of our sample the push-off impairment (85% of cases) and not the inappropriate knee extension moment produced by the thigh muscles was the primary cause of SKG. This result could explain the low average efficacy (<10°) of focal and surgical treatments at the quadriceps. The presented model could be used to differentiate the primary cause of SKG between inadequate push-off and braking activity of the thigh muscles, thus increasing the effectiveness of the selected treatment.

Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome.

Patellofemoral Pain Syndrome (PFPS) is a common musculoskeletal complaint. The presence of a delay between vastus medialis obliquus (VMO) and vastus lateralis (VL) muscle onset has been suggested in the literature as a possible cause of PFPS, with poor agreement amongst authors on the value of the delay. In this study we computed the delay in the activation of VMO and VL in 15 PFPS patients and 20 age-matched controls (Ctrls) during the following tasks: sit to stand, stand to sit, squat, step up and step down. Activation instants were detected from surface EMG data by a double-threshold statistical detector. In order to compare the muscle activity throughout the task, we computed the delay between the instants in which the VMO and VL normalised envelopes reached subsequent normalised amplitude levels, until the envelope peak. In all investigated tasks but sit to stand, the onset delay was lower or equal then 0.02s, without group differences. Similarly, no differences between Ctrls and PFPS timing were found throughout all tasks, until the peak. Our results do not support the hypothesis that an onset delay between VMO and VL can be one of the causes of PFPS.

Reliability, smallest real difference and concurrent validity of indices computed from GRF components in gait of stroke patients.

We analysed reliability, smallest real difference (SRD) and concurrent validity of indices computed from the ground reaction force (GRF) vertical and fore-aft components in a sample of 56 patients with hemiparesis secondary to stroke. These parameters have been recommended for the assessment of weight-bearing and propulsion. The sample size was calculated based on guidelines for reliability studies and patient levels of impairment ranged from mild to severe. Reliability was assessed by the intraclass correlation coefficient (ICC), SRD was computed as the 95% confidence interval (CI) of the standard error and concurrent validity was assessed using the Spearman correlation coefficient between each index and gait speed, with the latter being used as the criterion standard. Excellent reliability (ICC>0.90) for all indices was achieved by averaging values of three consecutive gait trials. SRD ranged between 5% and 10% of the sample grand mean for vertical GRF-based indices, and between 20% and 40% for fore-aft GRF-based indices. All indices but one showed concurrent validity with walking speed, with correlation coefficients ranging from 0.423 (p<0.01) to 0.834 (p<0.01). Amongst studied indices, the mean value of vertical GRF and the mean value of the propulsive part of the fore-aft component showed the best performance in terms of ICC, SRD and concurrent validity. These appear to be the most appropriate indices to assess weight-bearing and propulsive ability, respectively, in this group.

Quantitative analysis of sit to stand movement: experimental set-up definition and application to healthy and hemiplegic adults.

Rising from a chair or sit to stand (STS) is a movement with a great clinical interest: it is meaningful in order to evaluate motor control and stability in patients with functional limitations. STS requires some skills, as coordination between trunk and lower limbs movements, correction of muscles strength, control of equilibrium and stability and it is often considered into clinical evaluation scales of different pathologies. In literature, although some studies are focused on STS, the essential functions of standing up are not well standardized and uniformly defined: for this reason its application in clinical centres is difficult. In this study an experimental set-up for acquisition of STS movement which is suitable for clinical applications has been proposed: first, it was studied in healthy subjects, to define a normative database of this specific motor task, then in pathological subjects (adults with hemiplegia), to quantify their functional limitation, using quantitative kinematic and kinetic parameters. The results showed that this experimental set-up is effective both in healthy and in pathological subjects; some significant parameters were identified and calculated in order to characterise and quantify the functional limitation of patients.

Effect of electrode location on EMG signal envelope in leg muscles during gait.

The aim of the study was to assess the variability of EMG signal envelope with electrode location during gait. Surface EMG signals were recorded from 10 healthy subjects from the tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscles. From TA, PL, GL and GM, signals were acquired using a two-dimensional grid of 4 x 3 electrodes (10 x 15 mm in size, as used in most gait laboratories) with 20-mm interelectrode distance in both directions. A similar grid of 3 x 3 electrodes was used for SO. EMG envelope was characterized by its peak value, area after normalization by the peak value, and time instant corresponding to the maximum. The maximum relative change in peak value with electrode location, expressed as a percentage of the peak value in the central location, was (mean+/-SD) 31+/-18% for TA, 29+/-13% for PL, 25+/-15% for GL, 14+/-8% for GM, and 26+/-14% for SO. The maximum relative change in area was 29+/-13% for TA, 73+/-40% for PL, 31+/-23% for GL, 35+/-20% for GM, 20+/-13% for SO, and in the position of maximum, computed as distance from the maximum position in the central channel, it was 5+/-10% of the gait cycle for TA, 26+/-16% for PL, 3+/-2% for GL, 3+/-1% for GM, 3+/-3% for SO. A crosstalk index, defined on the basis of the expected intervals of muscle activation for healthy subjects, indicated that estimated crosstalk was present between TA and PL, in an amount which depended on electrode location. It was concluded that the estimate of muscle activation intensity during gait from surface EMG is variable with location of the electrodes while timing of muscle activity is more robust to electrode displacement and can be reliably extracted in those cases in which crosstalk is limited. These results are valid for healthy subjects, where the level of muscular activity during gait is much lower than maximum.