Biomedical subjects

Natasa Kavcic

Publications and source records attributed to Natasa Kavcic.

3 recordsLinked to original sources

PubMed2004

Quantifying tissue loads and spine stability while performing commonly prescribed low back stabilization exercises.

STUDY DESIGN: A quantitative biomechanical comparison of seven different lumbar spine "stabilization exercises." OBJECTIVES: The purpose of this research was to quantify lumbar spine stability resulting from the muscle activation patterns measured when performing selected stabilization exercises. SUMMARY OF BACKGROUND DATA: Many exercises are termed "stabilization exercises" for the low back; however, limited attempts have been made to quantify spine stability and the resultant tissue loading. Ranking resultant stability together with spinal load is very helpful for guiding clinical decision-making and therapeutic exercise design. METHODS: Eight stabilization exercises were quantified in this study. Spine kinematics, external forces, and 14 channels of torso EMG were recorded for each exercise. These data were input into a modified version of a lumbar spine model described by Cholewicki and McGill (1996) to quantify stability and L4-L5 compression. RESULTS: A rank order of the various exercises was produced based on stability, muscle activation levels, and lumbar compression. CONCLUSIONS: Quantification of the calibrated muscle activation levels together with low back compression and resultant stability assists clinical decisions regarding the most appropriate exercise for specific patients and specific objectives.

Adult↗

PubMed2004

Determining the stabilizing role of individual torso muscles during rehabilitation exercises.

STUDY DESIGN: A systematic biomechanical analysis involving an artificial perturbation applied to individual lumbar muscles in order to assess their potential stabilizing role. OBJECTIVES: To identify which torso muscles stabilize the spine during different loading conditions and to identify possible mechanisms of function. SUMMARY OF BACKGROUND DATA.: Stabilization exercises are thought to train muscle patterns that ensure spine stability; however, little quantification and no consensus exists as to which muscles contribute to stability. METHODS: Spine kinematics, external forces, and 14 channels of torso electromyography were recorded for seven stabilization exercises in order to capture the individual motor control strategies adopted by different people. Data were input into a detailed model of the lumbar spine to quantify spine joint forces and stability. The EMG signal for a particular muscle was replaced either unilaterally or bilaterally by a sinusoid, and the resultant change in the stability index was quantified. RESULTS: A direction-dependent-stabilizing role was noticed in the larger, multisegmental muscles, whereas a specific subtle efficiency to generate stability was observed for the smaller, intersegmental spinal muscles. CONCLUSIONS: No single muscle dominated in the enhancement of spine stability, and their individual roles were continuously changing across tasks. Clinically, if the goal is to train for stability, enhancing motor patterns that incorporate many muscles rather than targeting just a few is justifiable.

Adult↗

PubMed2003

Coordination of muscle activity to assure stability of the lumbar spine.

The intention of this paper is to introduce some of the issues surrounding the role of muscles to ensure spine stability for discussion -- it is not intended to provide an exhaustive review and integration of the relevant literature. The collection of works synthesized here point to the notion that stability results from highly coordinated muscle activation patterns involving many muscles, and that the recruitment patterns must continually change, depending on the task. This has implications on both the prevention of instability and clinical interventions with patients susceptible to sustaining unstable events.

Biomechanical Phenomena↗