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Altered Dynamic Postural Control during Step Turning in Persons with Early-Stage Parkinson's Disease.

Song J, Sigward S, Fisher B, Salem GJ - Parkinsons Dis (2012)

Bottom Line: Dynamic postural control was quantified as the distance between the center of pressure (COP) and the extrapolated center of mass (eCOM).Individuals with EPD demonstrated significantly shorter COP-eCOM distances compared to HC.These findings suggest that dynamic postural control during turning is altered even in the early stages of PD.

View Article: PubMed Central - PubMed

Affiliation: Jacquelin Perry Musculoskeletal Biomechanics Research Laboratory, Division of Biokinesology and Physical Therapy, University of Southern California, Los Angeles, CA 90089-9006, USA.

ABSTRACT
Persons with early-stage Parkinson's disease (EPD) do not typically experience marked functional deficits but may have difficulty with turning tasks. Studies evaluating turning have focused on individuals in advanced stages of the disease. The purpose of this study was to compare postural control strategies adopted during turning in persons with EPD to those used by healthy control (HC) subjects. Fifteen persons with EPD, diagnosed within 3 years, and 10 HC participated. Participants walked 4 meters and then turned 90°. Dynamic postural control was quantified as the distance between the center of pressure (COP) and the extrapolated center of mass (eCOM). Individuals with EPD demonstrated significantly shorter COP-eCOM distances compared to HC. These findings suggest that dynamic postural control during turning is altered even in the early stages of PD.

No MeSH data available.


Related in: MedlinePlus

Resultant COP-eCOM distance (a), and resultant COP-COG distance (b), resultant COM velocity (c) between groups during the step turn cycle (±sd). HS: heel strike; TO: toe off; light gray line: persons with early-stage Parkinson's disease; black line: healthy control participants; gray shadow: double limb support time; white shadow: single limb support time. †denotes statistically significant difference between groups (P < 0.05). *denotes statistically significant difference between phases (P < 0.05).
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fig3: Resultant COP-eCOM distance (a), and resultant COP-COG distance (b), resultant COM velocity (c) between groups during the step turn cycle (±sd). HS: heel strike; TO: toe off; light gray line: persons with early-stage Parkinson's disease; black line: healthy control participants; gray shadow: double limb support time; white shadow: single limb support time. †denotes statistically significant difference between groups (P < 0.05). *denotes statistically significant difference between phases (P < 0.05).

Mentions: No significant group by phase interaction was found for dynamic postural control (F = 0.584, P = 0.453). Main effects of group and phase are found for dynamic postural control. Persons with EPD demonstrated statistically significant smaller peak COP-eCOM distances compared to HC participants during both Phase 1 (20.6% difference; 0.34 ± 0.05 versus 0.41 ± 0.06 m; P < 0.01) and Phase 2 (21.1% difference; 0.38 ± 0.06 versus 0.46 ± 0.07 m; P = 0.01) of the step turn (Figure 3(a)). The peak distance between the COP and the eCOM always occurred during single limb stance within each of the phases.


Altered Dynamic Postural Control during Step Turning in Persons with Early-Stage Parkinson's Disease.

Song J, Sigward S, Fisher B, Salem GJ - Parkinsons Dis (2012)

Resultant COP-eCOM distance (a), and resultant COP-COG distance (b), resultant COM velocity (c) between groups during the step turn cycle (±sd). HS: heel strike; TO: toe off; light gray line: persons with early-stage Parkinson's disease; black line: healthy control participants; gray shadow: double limb support time; white shadow: single limb support time. †denotes statistically significant difference between groups (P < 0.05). *denotes statistically significant difference between phases (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3306994&req=5

fig3: Resultant COP-eCOM distance (a), and resultant COP-COG distance (b), resultant COM velocity (c) between groups during the step turn cycle (±sd). HS: heel strike; TO: toe off; light gray line: persons with early-stage Parkinson's disease; black line: healthy control participants; gray shadow: double limb support time; white shadow: single limb support time. †denotes statistically significant difference between groups (P < 0.05). *denotes statistically significant difference between phases (P < 0.05).
Mentions: No significant group by phase interaction was found for dynamic postural control (F = 0.584, P = 0.453). Main effects of group and phase are found for dynamic postural control. Persons with EPD demonstrated statistically significant smaller peak COP-eCOM distances compared to HC participants during both Phase 1 (20.6% difference; 0.34 ± 0.05 versus 0.41 ± 0.06 m; P < 0.01) and Phase 2 (21.1% difference; 0.38 ± 0.06 versus 0.46 ± 0.07 m; P = 0.01) of the step turn (Figure 3(a)). The peak distance between the COP and the eCOM always occurred during single limb stance within each of the phases.

Bottom Line: Dynamic postural control was quantified as the distance between the center of pressure (COP) and the extrapolated center of mass (eCOM).Individuals with EPD demonstrated significantly shorter COP-eCOM distances compared to HC.These findings suggest that dynamic postural control during turning is altered even in the early stages of PD.

View Article: PubMed Central - PubMed

Affiliation: Jacquelin Perry Musculoskeletal Biomechanics Research Laboratory, Division of Biokinesology and Physical Therapy, University of Southern California, Los Angeles, CA 90089-9006, USA.

ABSTRACT
Persons with early-stage Parkinson's disease (EPD) do not typically experience marked functional deficits but may have difficulty with turning tasks. Studies evaluating turning have focused on individuals in advanced stages of the disease. The purpose of this study was to compare postural control strategies adopted during turning in persons with EPD to those used by healthy control (HC) subjects. Fifteen persons with EPD, diagnosed within 3 years, and 10 HC participated. Participants walked 4 meters and then turned 90°. Dynamic postural control was quantified as the distance between the center of pressure (COP) and the extrapolated center of mass (eCOM). Individuals with EPD demonstrated significantly shorter COP-eCOM distances compared to HC. These findings suggest that dynamic postural control during turning is altered even in the early stages of PD.

No MeSH data available.


Related in: MedlinePlus