Andrej Panjan

Review of Methods for the Evaluation of Human Body Balance

Review of Methods for the Evaluation of Human Body Balance The aim of this review paper is to thoroughly present all main tests used today in the field of body balance/equilibrium assessment and evaluation. After the introduction of some basic biomechanical and movement regulation concepts, a short revision of the metric characteristics that each test should contain is discussed. The latter encompasses validity, objectivity, repeatability, sensitivity, and some other elements that are of crucial importance for the practical use of every assessment. The major part of text is dedicated to the critical research based review of the body balance tests of different levels of technical and other complexity. Pros and cons of the presented assessment methods are discussed. First, the field motor tests and simple clinical tests are presented. Their primary use in school physical education, sports medicine, and rehabilitation is pointed out. Second, laboratory tests for the static balance assessment are described in details, including all the measured parameters, their informational value and limitations. And third, laboratory tests for the evaluation of dynamic balance are presented in an analogue way. In the discussion, we compare different tests through the scope of usefulness, economy, metric characteristics and informational value. The paper closes with a summary of the state-of-the-art on the field of balance and proposals for future research work.

Adjusted saddle position counteracts the modified muscle activation patterns during uphill cycling

The main aim of this project was to study muscle activity patterns during steep uphill cycling (UC) (i.e., with a gradient of 20%) with (1) normal saddle geometry and (2) with adjusted saddle position ASP (i.e., moving the saddle forward and changing the tilt of the saddle by 20%). Based on our preliminary case study, we hypothesized that: (1) during 20% UC muscle activity patterns would be different from those of level cycling (LC) and (2) during 20% UC with ASP muscle activity patterns would resemble those of LC. Twelve trained male cyclists were tested on an electromagnetically braked cycle ergometer under three conditions with the same work rate (80% of maximal power output) and cadence (90 rpm): level (LC), 20% UC and 20% UC with ASP. Electromyographic signals were acquired from m. tibialis anterior (TA), m. soleus (SO), m. gastrocnemius (GC), m. vastus lateralis (VL), m. vastus medialis (VM), m. rectus femoris (RF), m. biceps femoris (BF) and m. gluteus maximus (GM). Compared to LC, 20% UC significantly modified both the timing and the intensity of activity of the selected muscles, while muscles that cross the hip joint were the most affected (RF later onset, earlier offset, shorter range of activity and decrease in peak amplitude of 34%; BF longer range of activity; GM increase in peak amplitude of 44%). These changes in EMG patterns during 20% UC were successfully counteracted by the use of ASP and it was interesting to observe that the use of ASP during 20% UC was perceived positively by all cyclists regarding both comfort and performance. These results could have a practical relevance in terms of improving performance during UC, together with reducing discomfort.

The effects of aging on the rambling and trembling components of postural sway: Effects of motor and sensory challenges

The effects of healthy aging on postural sway and its rambling and trembling components were studied. Young and elderly subjects stood quietly for 1 min in different postures, and with eyes open and closed. We found that age-related changes in postural sway and its components were similar to those observed in young participants in challenging conditions. These changes may therefore be viewed as secondary to the increased subjective perception of the complexity of postural tasks. Contrary to our expectations, stronger effects of age were seen in characteristics of rambling, not trembling. The commonly accepted hypothesis that older persons rely on vision more was not supported by this study: we found no significant interaction effects of age and vision on any of the sway characteristics. It was concluded that the reported higher reliance on vision in older persons may be task-specific. The results are compatible with the ideas that much of the age-related changes in postural sway emerge at the level of exploring the limits of stability and using the drift-and-act strategy. Our results suggest that the dominant view on rambling and trembling as reflecting supraspinal and peripheral mechanisms, respectively, may be too simplistic.

Effect of sacroiliac manipulation on postural sway in quiet standing: a randomized controlled trial

Highlights • Postural sway demonstrated no difference between manipulation and sham treatment.• Sacroiliac manipulation did not disturb balance as rambling or center of pressure showed no significant change.• Sacroiliac manipulation increased trembling frequency and velocity in the manipulation group.• Balance changes were shown to be minor with SI manipulation and may be compensated by ankle strategy.

Effect of Functional Electrical Stimulation on the Central State of Excitability of the Spinal Cord

The recent years brought a growing awareness for the existence of complex neuronal structures within the spinal cord that act as movement controllers. The presented pilot study addresses an extension of pure non-invasive spinal cord stimulation by adding an afferent input from electrically stimulated peripheral nerve. The goal was to assess electrophysiologically the influence of peripheral nerve stimulation (peroneal nerve) on the function of the lumbar spinal cord neural circuitries.