The effect of foot wedging on electromyographic activity in the erector spinae and gluteus medius muscles during walking

EMG and kinematics analysis of the trunk and lower extremity during the sit-to-stand task while wearing shoes with different heel heights in healthy young women

This study investigated the EMG characteristics and the kinematics of the trunk and lower extremity during the sit-to-stand (STS) task while wearing 1-, 4-, and 8-cm high-heeled shoes. We examined differences in the EMG data of the internal oblique, erector spinae, medial hamstring, and rectus femoris muscles during the STS task. The motion of the hip joint during an STS task was measured with a NorAngle Electrogoniometer System. Twelve young healthy women were recruited to this study. EMG characteristics and the hip joint angle were recorded during the performance of an STS task by subjects wearing high-heeled shoes of three different heel heights. The muscle onset time and EMG activity during this task were analyzed. In 8-cm high-heeled shoes, the onset time for the erector spinae muscle was significantly delayed, and the onset latency for the medial hamstring and the rectus femoris was significantly decreased. There was increased activity in the erector spinae and rectus femoris muscle during this task when wearing 8-cm high-heeled shoes. The initial hip flexion angle at the start point of the STS task did not differ among the 1-, 4-, and 8-cm heel-height conditions, but the trunk flexion angle, corresponding to the displacement between the peak hip flexion and initial hip flexion, was significantly larger in the 8-cm heel-height condition than in the 1- and 4-cm heel-height conditions. The findings suggest that excessive heel height has the potential to induce muscle imbalance during the STS task.

Augmented low dye taping changes muscle activation patterns and plantar pressure during treadmill running

STUDY DESIGN

Randomized, crossover study.

OBJECTIVE

To examine changes in muscle activity and plantar pressure during running with the application of augmented low Dye (ALD) taping.

BACKGROUND

ALD taping is used clinically as part of management for lower limb injury. As of yet, no studies have examined the effect of this taping method on muscle activity and plantar pressure during running, simultaneously.

METHODS

Thirteen healthy recreational runners(mean ± SD age, 31.7 ± 4.9 years; height, 181.7 ± 4.6 cm; body mass, 81.6 ± 5.9 kg) completed a 6-minute run on a treadmill at a speed of 10 km·h⁻¹, with 3 different taping conditions (ALD, control tape, no tape), applied in randomized order. Peak and average EMG signal amplitude, onset time, and burst duration were calculated for the vastus medialis, vastus lateralis, and the gluteus medius. In-shoe plantar pressures were also recorded. All data were calculated based on an average of 20 steps collected after 5 minutes of treadmill running.

RESULTS

ALD taping significantly altered muscle activity and plantar pressure during treadmill running by (1) delaying the onset of the EMG signal of the gluteus medius, vastus medialis, and vastus lateralis, and (2) increasing lateral midfoot plantar pressure.

CONCLUSION

ALD taping significantly alters plantar pressure and muscle activation patterns during treadmill running. These findings give insight into the neuromuscular effect of a taping procedure that is used commonly in a clinical setting.

Early observations of the effects of lateral wedge orthoses on lower limb muscle length and potential for exacerbating spasticity

Lateral wedge orthoses are often prescribed to correct varus deformity after stroke. Spasticity is implicated in varus deformity and is caused by velocity-related muscle length changes, so a lateral wedge may affect spasticity by manipulating foot and ankle kinematics which, in turn, may alter the length of these muscles. We sought to test this theory in healthy participants. Eight volunteers walked with no wedge and with lateral wedges of 5 and 8.5 degrees in both shoes. Qualysis motion capture system collected kinematic data and SIMM musculoskeletal modeling software calculated muscle tendon length of plantarflexor and peroneal muscle groups using 3-D ankle and knee joint angle data. The wedges increased ankle eversion (p < 0.0001) and total excursion of tibialis posterior, peroneus longus and brevis by 13-29% (p < 0.05). Muscle length of peroneus longus and brevis increased by <1% (p < 0.005). Potentially clinical meaningful effects were found for tibialis posterior (15%), peroneus brevis (23%) and peroneus tertius (13%). Further research is required to be conclusive and to explore the effects of lateral wedge orthoses in patients with stroke. If such changes are seen in people with stroke, a change in orthotic prescription practice could be indicated as lateral wedge orthoses may exacerbate spasticity.

A novel biomechanical device improves gait pattern in patient with chronic nonspecific low back pain

STUDY DESIGN

A retrospective study on patients with chronic nonspecific low back pain (NSLBP).

OBJECTIVE

To describe the gait stride characteristics of patients with chronic NSLBP, and to examine the effect of a novel biomechanical device on the gait stride characteristics of these patients.

SUMMARY OF BACKGROUND DATA

Patient with NSLBP alters their gait patterns. This is considered a protective mechanism as patients try to avoid extensive hip and spine ranges of motion and minimize forces and moments acting on the body. In addition, there are changes in the neuromuscular control system in patients with LBP that could possibly be attributed to the effects of pain on motor control.

METHODS

Nineteen patients underwent a gait test, using an electronic walkway, at baseline and after 12 weeks of treatment. Spatiotemporal parameters were used to identify changes in gait pattern. A novel biomechanical device comprised of 4 modular elements attached to foot-worn platforms was used in the study. The modules are 2 convex shaped biomechanical elements attached to each foot, one is located under the hindfoot region and the other is located under the forefoot region. The device was individually calibrated to each patient. The patients were instructed to walk with the calibrated biomechanical device on a daily basis for a period of 12 weeks.

RESULTS

Significant differences were found at baseline and after 12 weeks in normalized velocity (P = 0.03), cadence (P < 0.01), left normalized step length (P = 0.02), right normalized step length (P = 0.02), right swing (P < 0.01), right stance (P < 0.01), left single limb support (P = 0.01), left double limb support (P = 0.02), and right double limb support (P = 0.02).

CONCLUSION

Patients with NSLBP treated with the novel biomechanical device for 3 months increased walking speed through longer step length and eliminated asymmetrical differences.

Effect of foot posture, foot orthoses and footwear on lower limb muscle activity during walking and running: a systematic review

The aim of this systematic review was to evaluate the literature pertaining to the effect of foot posture, foot orthoses and footwear on lower limb muscle activity during walking and running. A database search of Medline, CINAHL, Embase and SPORTDiscus without language restrictions revealed 504 citations for title and abstract review. Three articles were translated to English and a final 46 articles underwent a two-tiered quality assessment. First, all articles were scored for their reporting of electromyographic methodology using a set of standards adopted by the International Society of Electrophysiology and Kinesiology. Thirty-eight articles displayed adequate reporting of electromyographic methodology and qualified for detailed review including a second quality assessment using a modified version of the Quality Index. These included six studies investigating the effect of foot posture, 12 the effect of foot orthoses and 20 the effect of footwear on lower limb muscle activity during walking or running. Meta-analysis was not conducted due to heterogeneity between studies. Some evidence exists that: (i) pronated feet demonstrate greater electromyographic activation of invertor musculature and decreased activation of evertor musculature; (ii) foot orthoses increase activation of tibialis anterior and peroneus longus, and may alter low back muscle activity; and (iii) shoes with elevated heels alter lower limb and back muscle activation. Most studies reported statistically significant changes in electromyographic activation, although these findings were often not well supported when confidence intervals were calculated. Most important, however, is that there is a need for further research of more rigorous methodological quality, including greater consensus regarding standards for reporting of electromyographic parameters.

The effect of three levels of foot orthotic wedging on the surface electromyographic activity of selected lower limb muscles during gait

BACKGROUND

Some types of foot orthoses have been researched for their effect on lower limb electromyographic muscle activity during walking. However, foot orthoses with high levels of medial rearfoot wedging ('inverted' foot orthoses) have not been investigated.

METHODS

In a cross-sectional study, asymptomatic participants with a pronated foot type (n=15) were each issued with a pair of 0 degrees, 15 degrees and 30 degrees inverted custom-made foot orthoses. After four weeks of habituation to the orthoses, surface electromyography was used to measure the onset and maximum EMG amplitude of tibialis anterior, peroneus longus, medial gastrocnemius and soleus muscles using five conditions [barefoot, shoe-only, 0 degrees, 15 degrees and 30 degrees inverted foot orthoses conditions].

FINDINGS

A statistically significant increase in tibialis anterior maximum EMG amplitude occurred using the shoe only (30% increase), 0 degrees (33% increase), 15 degrees (38% increase) and 30 degrees (30% increase) inverted orthoses conditions compared to walking barefoot (P<0.01). Peroneus longus maximum EMG amplitude increased significantly using the 15 degrees inverted orthosis condition compared to walking barefoot (21% increase, P=0.04).

INTERPRETATION

Footwear and orthoses can significantly alter the maximum EMG amplitude of leg muscles during walking. Foot orthoses appear to increase peroneus longus EMG amplitude compared to footwear alone. However, the level of medial rearfoot posting within an orthosis does not appear to significantly alter maximum EMG amplitude. The individual responses to foot orthoses are highly variable. The changes in EMG amplitude with the use of foot orthoses and shoes may have clinical implications.