The kinematics of the scapulae and spine during a lifting task

Simultaneous motion of the scapula and humerus is widely accepted as a feature of normal upper limb movement, however this has usually been investigated under conditions in which purposeful, functional tasks were not considered. The aim of this study was to investigate the synchrony and coordination of the constituent 3D movements of the shoulder girdle and trunk, during a functional activity. 45 healthy women, aged between 20 and 80 years, performed a simple lifting task, moving a loaded box from a shelf at waist level to one at shoulder level and then reversed the movement, during which the linear and angular motions of the scapulae, upper and lower thoracic spine and upper limbs were monitored and analysed using cross-correlation techniques. Results indicated a close and consistent set of coordinated movement patterns, which suggest biomechanical invariance in the responses of the structures adjacent to the upper limb during such a lifting task. These scapulohumeral relationships were, however, more constant and phase-locked when there was a specific purpose to the movement than during periods in which the arm was lowered without load. There were no age-related differences in any movement responses

Prevalence and risk factors associated with pain 21 months following surgery for breast cancer

Purpose: This study investigated (1) the prevalence of pain following breast cancer treatment including moderate-to-severe persistent pain and (2) the association of risk factors, present 1 month following surgery, with pain at 21 months following surgery. This information may aid the development of clinical guidelines for early pain assessment and intervention in this population. Methods: This study was a retrospective analysis of core and breast modules of the European Organisation for Research and Treatment of Cancer (EORTC) questionnaire from 121 participants with early breast cancer. The relationships between potential risk factors (subscales derived from the EORTC), measured within 1 month following surgery, and pain at 21 months following surgery were analysed using univariable and multi-variable logistic regression. Results: At 21 months following surgery, 46.3 % of participants reported pain, with 24 % categorised as having moderate or severe pain. Prevalence of pain was similar between those who underwent axillary lymph node dissection versus biopsy. Univariate logistic regression identified baseline pain (odds ratio (95 % CI): 2.7 (1.1 to 6.4)); baseline arm symptoms (11.2 (1.4 to 89.8)); emotional function (0.4 (0.1 to 0.8)) and insomnia (2.3 (1.1 to 4.7) as significantly associated with pain at 21 months. In multi-variable analysis, two factors were independently associated with pain at 21 months-baseline arm symptoms and emotional subscale scores. Conclusion: Pain is a significant problem following breast cancer treatment in both the early post-operative period and months following surgery. Risk factors for pain at long-term follow-up included arm symptoms and higher emotional subscale scores at baseline.7 page(s

Bioimpedance spectroscopy of the breast

Background: Bioimpedance spectroscopy (BIS) measurements of breast lymphedema poses practical and technical challenges, in particular the determination of the resistance at zero frequency (R-0), the index of change in breast lymph content. Conventionally, R-0 is calculated from data analysis by using a procedure eponymously known as Cole modeling, a method that is error-prone in the breast. The aim of this study was to evaluate polynomial curve fitting as an alternative analytic procedure.Methods and Results: A sub-set of breast BIS measurements from 41 women with self-ascribed breast lymphedema obtained as part of the Breast Edema Exercise Trial (BEET) were analyzed by both the Cole and polynomial methods. BIS files for all subjects were able to be analyzed by using the polynomial method but only 73% and 88% of data files were analyzed for the affected and unaffected breasts, respectively, by using the Cole method. For those files that were capable of being analyzed by both methods, R-0 values were highly correlated (r = 0.99) but with a small (1.6%) although statistically significant difference (paired t test, p < 0.001) between methods.Conclusions: Analysis of BIS data using polynomial curve fitting is an acceptable and robust alternative to Cole modeling, particularly where impedance measurements are susceptible to technical sources of error of measurement. The small magnitude of difference observed between methods is unlikely to lead to misclassification of patients with lymphedema based on BIS assessment

Electrode equivalence for use in bioimpedance spectroscopy assessment of lymphedema

Bioimpedance spectroscopy (BIS) is commonly used in the assessment and monitoring of lymphedema. This study investigated electrodes as a source of variability that could impact the accuracy of BIS in the clinic and determined if Ag/AgCl electrocardiograph (ECG) electrodes could be used as an alternative to instrument-specific electrodes.Two types of Ag/AgCl electrodes were studied: instrument-specific bioimpedance electrodes (bioimpedance) and single tab ECG electrodes (cardiac). Six areas of investigation were addressed: intrinsic electrode resistance; electrode age; drive electrode position; electrode width/surface area; concordance between cardiac and bioimpedance electrodes; and mixing electrode types and batches. Participants included women (n = 26) and men (n = 8), both with (n = 4) and without lymphedema (n = 30). Resistance (R) of the limbs was measured and used to calculate interlimb BIS ratios. Intrinsic electrode resistance varied between batches (p ≤ 0.001), with cardiac electrodes recording higher resistance. Electrode age had no impact on limb resistance (p = 0.85). Drive electrode position biased limb resistance (0.1%-2.3%) and electrode size/surface area had a small (≤1%), but significant effect on limb resistance (p ≤ 0.001). However, calculation of interlimb BIS ratios negated the impact of these as well as any effect of mixing electrode batches and types (p = 0.15-0.96). Electrode type had no impact on arm and leg resistance, or interlimb BIS ratios (p = 0.173-0.289).Calculation of interlimb BIS ratios improves accuracy of clinical BIS. Ag/AgCl cardiac electrodes can be used as an alternative to device-specific electrodes to measure limb resistance