Concurrent validity and reliability of using ground reaction force and center of pressure parameters in the determination of leg movement initiation during single leg lift

Differences in balance control despite self-reported resolution of pregnancy-related pelvic girdle pain. A cross-sectional study

BACKGROUND

Motor control patterns are altered when women with pregnancy-related pelvic girdle pain (PGP) experience pain. In low back pain, these adaptations can persist after recovery.

OBJECTIVES

This study aimed to assess balance control in postpartum women with and without a history of PGP during pregnancy.

DESIGN

Cross-sectional study.

METHOD

Eighteen postpartum women who reported to be recovered from PGP, and twelve postpartum women without a history of PGP during pregnancy performed two clinical tests: the single leg stance and active straight leg raise test. Primary outcomes were ground reaction forces measured with a force platform.

RESULTS

Multiple linear regression analyses showed smaller lateral displacement (β = -11cm; 95%CI: 19 to -3; p = 0.008) and lower displacement velocity of the Centre of Pressure (COP) (Ratio of Geometric Means (RGM) 0.76; 95%CI: 0.59 to 0.99; p = 0.043) during single leg stance in the participants with a history of PGP compared to participants without a history of PGP. Push-off force (β = -4.8 N; 95%CI: 22.0 to 12.5; p = 0.57) and asymmetry of push-off force (RGM 1.77; 95%CI: 0.62 to 5.04; p = 0.27) did not differ between groups. During the active straight leg raise test, no differences in lateral displacement (β = 3 cm; 95%CI: 3 to 8; p = 0.30) and COP displacement velocity (RGM 1.03; 95%CI: 0.70 to 1.52; p = 0.87) were observed.

CONCLUSIONS

Although the women with a history of PGP considered themselves recovered, their balance control during single leg stance was poorer compared to those without a history of PGP. No differences were found during the active straight leg raise test.

A multivariate model for predicting PPGP considering postural adjustment parameters

BACKGROUND

Prospective studies have described evidence about the risk of developing pregnancy-related pelvic girdle pain (PPGP) such as, parity, previous history of low back and pelvic girdle pain. No previous studies have prospectively associated PPGP with postural control.

AIM

This study aimed to identify postural control predictors of PPGP during pregnancy.

METHODS

Forty-six pregnant women were surveyed throughout their pregnancy for the presence of PPGP. At baseline, participants were evaluated for muscle latencies, mediolateral centre-of-pressure (COP) displacement and velocity during single-leg lift performed with eyes open and closed. PPGP was considered if they presented with one positive clinical assessment as well as pain within the pelvic area.

RESULTS

Eighteen (45%) of the participants developed PPGP. This group presented with PPGP around a mean 29th week (SD = 5.7), with mean pelvic pain intensity of 4 mm VAS (SD = 2) on a (0-10 cm VAS) and mean PPGP questionnaire score of 21.5 points (SD = 10.6) out of a possible 100 points with 0 indicating no functional disability. The two factors that were significantly associated with PPGP were the right and left biceps femoris (BF) muscle. For every 50 ms of difference of BF muscles latency between eyes open and closed, the risk of PPGP increases by 20% (right BF) and 30% (left BF) to develop PPGP.

CONCLUSION(S)

This study shows that BF muscle delay during single-leg lift presented at baseline was a significant predictor for the development of PPGP in late pregnancy.

Use of 3D-Printed Heel Support Insoles Based on Arch Lift Improves Foot Pressure Distribution in Healthy People

Background

3D-printed insoles are widely used. This study was conducted to test a customized three-dimensional (3D)-printed heel support insole based on arch lift and to investigate whether the pressure distribution on the sole was improved while maintaining foot function.

Material/Methods

The design was based on a 3D plantar contour scanning modeling technique. Thirty healthy male participants walked along a 10-m track under 3 self-controlled interventions. A customized 3D-printed heel support insole based on arch lift was inserted into the socks for the experimental condition A. For condition B, a customized 3D-printed heel-supporting insole was inserted into the socks, and a standardized pre-made heel-supporting insole was inserted into the socks as a control (condition C). We used the Footscan^® pressure plate to measure the plantar parameters in the forefoot contact and foot flange phases in each condition.

Results

Compared with condition B and the control condition, the peak pressure under the heel was significantly lower in condition A (P<0.05), and the peak pressure in the midfoot region was not significantly increased (P>0.05).

Conclusions

The biomechanical properties of the customized 3D-printed heel support are better than those of the traditional heel support insole, especially when there is a need for an additional increase in heel height. Patients do not decrease midfoot motion function while using this customized insole.