Effect of insole material on force and plantar pressures during walking

1992 ◽  
Vol 82 (8) ◽  
pp. 412-416 ◽  
Author(s):  
TG McPoil ◽  
MW Cornwall
Keyword(s):  
Plantar Pressure ◽  
Vertical Force ◽  
Pressure Data ◽  
Plantar Pressures ◽  
Time Integral ◽  
Force Time ◽  
Force Time Integral

Twelve subjects between the ages of 24 and 35 years walked barefoot over a pressure platform with the following insole materials placed directly on top of the platform: 1) PPT, 2) Spenco, and 3) Viscolas. Maximum vertical force, vertical force-time integral as well as maximum plantar pressure data were collected for the rearfoot, midfoot, and forefoot regions. The results were not significant for maximum vertical force and vertical force-time integral among the three insole materials when compared to barefoot-only walking. There was, however, a significant reduction in forefoot maximum plantar pressure among the three materials compared to barefoot-only walking. In the rearfoot region, a reduction in maximum plantar pressure was seen only with PPT and Spenco.

Dynamic plantar pressure analysis. Comparing common insole materials

1992 ◽  
Vol 82 (10) ◽  
pp. 507-513 ◽  
Author(s):  
PB Sanfilippo ◽  
RM Stess ◽  
KM Moss
Keyword(s):  
Plantar Pressure ◽  
Human Subjects ◽  
Force Plate ◽  
Vertical Force ◽  
Time Integral ◽  
Pressure Time ◽  
Peak Plantar Pressure ◽  
Force Time ◽  
Dynamic Measures ◽  
Force Time Integral

A comparison of five commonly used insole materials (Spenco, PPT, Plastazote, Nickelplast, and Pelite) was made to evaluate their effectiveness in reducing plantar vertical pressures on human subjects during walking. With the use of the EMED-SF pedograph force plate system, dynamic measures of vertical force, force-time integral, peak plantar pressure, pressure-time integral, and area of foot-to-ground contact were compared with the force plate covered with each of the insole materials and without any interface material.

THE EFFECTS OF CHANGES IN STEP WIDTH ON PLANTAR FOOT PRESSURE PATTERNS OF YOUNG FEMALE SUBJECTS DURING WALKING

2011 ◽  
Vol 11 (05) ◽  
pp. 1071-1083 ◽  
Author(s):  
SU-YA LEE ◽  
CHEN-YU CHOU ◽  
YI-YOU HOU ◽  
YU-LIN WANG ◽  
CHICH-HAUNG YANG ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Plantar Pressure ◽  
Reaction Force ◽  
Lateral Side ◽  
Step Width ◽  
Foot Pressure ◽  
Time Integral ◽  
Pressure Time ◽  
Force Time ◽  
Force Time Integral

The aim of this study was to investigate the foot plantar pressure distribution and the effect of different step width during walking. Methods: Nineteen female volunteers who aged 18~30 years old and with no history of lower extremity injury were considered. Subjects walked at a pre-determined set speed with varied step width (5 cm, 10 cm, and 20 cm) for three trials at each step width. This study used an in-sole plantar pressure measurement system to collect the peak pressure, maximum ground reaction force, pressure–time integral, and force–time integral data of eight different foot regions. Results: The data revealed that the peak plantar foot pressure on the medial arch increased with wider step width (p < 0.05). In contrast, maximum ground reaction force, peak plantar pressure, pressure–time integral, and force–time integral on the lateral arch and lateral side of the metatarsals decreased with wider step width (p < 0.05). Conclusion: The results of this study revealed that smaller step width during walking result in decreasing the pressure on the medial arch of the foot. It may have the relieving effect for clients with pes planus and it can be a reference for rehabilitation clinicians while treating the above-mentioned subjects.

scholarly journals Rehabilitation After Hallux Valgus Surgery: Importance of Physical Therapy to Restore Weight Bearing of the First Ray During the Stance Phase

2009 ◽  
Vol 89 (9) ◽  
pp. 934-945 ◽  
Author(s):  
Reinhard Schuh ◽  
Stefan G. Hofstaetter ◽  
Samuel B. Adams ◽  
Florian Pichler ◽  
Karl-Heinz Kristen ◽  
...  
Keyword(s):  
Hallux Valgus ◽  
Plantar Pressure ◽  
Weight Bearing ◽  
Metatarsophalangeal Joint ◽  
Rehabilitation Program ◽  
First Metatarsophalangeal Joint ◽  
Time Integral ◽  
First Ray ◽  
Force Time ◽  
Force Time Integral

Background Operative treatment of people with hallux valgus can yield favorable clinical and radiographic results. However, plantar pressure analysis has demonstrated that physiologic gait patterns are not restored after hallux valgus surgery. Objective The purpose of this study was to illustrate the changes of plantar pressure distribution during the stance phase of gait in patients who underwent hallux valgus surgery and received a multimodal rehabilitation program. Design This was a prospective descriptive study. Methods Thirty patients who underwent Austin (n=20) and scarf (n=10) osteotomy for correction of mild to moderate hallux valgus deformity were included in this study. Four weeks postoperatively they received a multimodal rehabilitation program once per week for 4 to 6 weeks. Plantar pressure analysis was performed preoperatively and 4 weeks, 8 weeks, and 6 months postoperatively. In addition, range of motion of the first metatarsophalangeal joint was measured, and the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot questionnaire was administered preoperatively and at 6 months after surgery. Results The mean AOFAS score significantly increased from 60.7 points (SD=11.9) preoperatively to 94.5 points (SD=4.5) 6 months after surgery. First metatarsophalangeal joint range of motion increased at 6 months postoperatively, with a significant increase in isolated dorsiflexion. In the first metatarsal head region, maximum force increased from 117.8 N to 126.4 N and the force-time integral increased from 37.9 N·s to 55.6 N·s between the preoperative and 6-month assessments. In the great toe region, maximum force increased from 66.1 N to 87.2 N and the force-time integral increased from 18.7 N·s to 24.2 N·s between the preoperative and 6-month assessments. Limitations A limitation of the study was the absence of a control group due to the descriptive nature of the study. Conclusions The results suggest that postoperative physical therapy and gait training may lead to improved function and weight bearing of the first ray after hallux valgus surgery.

scholarly journals Force-time integral decreases with ejection despite constant oxygen consumption and pressure-volume area in dog left ventricle.

1987 ◽  
Vol 60 (6) ◽  
pp. 797-803 ◽  
Author(s):  
H Suga ◽  
Y Goto ◽  
T Nozawa ◽  
Y Yasumura ◽  
S Futaki ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Time Integral ◽  
Force Time ◽  
Force Time Integral

The Effect of Muscle Lentgh on Force-Time Integral in Relation to Energy-Rich Phosphate Consumption

1985 ◽  
pp. 605-610 ◽  
Author(s):  
A. De Haan ◽  
J. E. Van Doorn ◽  
P. A. Huijing ◽  
R. D. Woittiez ◽  
H. G. Westra
Keyword(s):  
Time Integral ◽  
Force Time ◽  
Force Time Integral

Regulation of energy consumption in cardiac muscle: analysis of isometric contractions

1999 ◽  
Vol 276 (3) ◽  
pp. H998-H1011 ◽  
Author(s):  
Amir Landesberg ◽  
Samuel Sideman
Keyword(s):  
Energy Consumption ◽  
Cardiac Muscle ◽  
Feedback Mechanism ◽  
Isometric Contractions ◽  
Cross Bridge ◽  
Time Integral ◽  
Length Relationship ◽  
Cross Bridges ◽  
Force Time ◽  
Force Time Integral

The well-known linear relationship between oxygen consumption and force-length area or the force-time integral is analyzed here for isometric contractions. The analysis, which is based on a biochemical model that couples calcium kinetics with cross-bridge cycling, indicates that the change in the number of force-generating cross bridges with the change in the sarcomere length depends on the force generated by the cross bridges. This positive-feedback phenomenon is consistent with our reported cooperativity mechanism, whereby the affinity of the troponin for calcium and, hence, cross-bridge recruitment depends on the number of force-generating cross bridges. Moreover, it is demonstrated that a model that does not include a feedback mechanism cannot describe the dependence of energy consumption on the loading conditions. The cooperativity mechanism, which has been shown to determine the force-length relationship and the related Frank-Starling law, is shown here to provide the basis for the regulation of energy consumption in the cardiac muscle.

Preload does not influence nonmechanical O2 consumption in isolated rabbit heart

1994 ◽  
Vol 266 (3) ◽  
pp. H1047-H1054 ◽  
Author(s):  
A. Higashiyama ◽  
M. W. Watkins ◽  
Z. Chen ◽  
M. M. LeWinter
Keyword(s):  
Energy Consumption ◽  
Diastolic Pressure ◽  
Rabbit Heart ◽  
Left Ventricular ◽  
Energetic Cost ◽  
O2 Consumption ◽  
Time Integral ◽  
Force Time ◽  
Whole Heart ◽  
Force Time Integral

Myocardial energy consumption for nonmechanical activity (excitation-contraction coupling) has been shown to be length dependent in isolated muscle studies but no more than minimally affected by preload in the whole heart. However, unloaded O2 consumption (VO2, which is used to estimate nonmechanical VO2 in whole heart) may not be accurate for quantifying nonmechanical energy consumption, because it contains VO2 for residual cross-bridge cycling. To more accurately determine the influence of left ventricular (LV) diastolic volume on nonmechanical VO2 in whole heart, we employed a new method for quantifying nonmechanical VO2, using the drug 2,3-butanedione monoxime (BDM). We measured VO2 and force-time integral during infusion of BDM (< or = 5 mM) at high (VH) and low LV volumes (VL) in 16 excised isovolumically contracting red blood cell-perfused rabbit ventricles. LV end-diastolic pressure was 9.7 +/- 4.6 and 3.8 +/- 2.8 (SD) mmHg at VH and VL, respectively. Nonmechanical VO2, estimated as the VO2-axis intercept of the linear VO2-force-time integral relation obtained during BDM infusion, did not differ significantly between VH and VL (0.0137 +/- 0.0083 and 0.0132 +/- 0.0090 ml O2.beat-1 x 100 gLV-1, P = 0.702). A multiple linear regression analysis for the pooled data confirmed this finding (P = 0.361). We conclude that, in the rabbit heart, LV diastolic volume does not importantly affect nonmechanical energy consumption over a physiological range of LV end-diastolic pressure. This indicates that length-dependent activation does not have an energetic cost in whole rabbit heart and suggests that its predominant mechanism is increased Ca2+ affinity for the contractile proteins.

scholarly journals Stimulation Pattern That Maximizes Force in Paralyzed and Control Whole Thenar Muscles

2002 ◽  
Vol 87 (5) ◽  
pp. 2271-2278 ◽  
Author(s):  
Lisa Griffin ◽  
Sharlene Godfrey ◽  
Christine K. Thomas
Keyword(s):  
Short Interval ◽  
Motor Units ◽  
Muscle Stiffness ◽  
Peak Force ◽  
Single Motor Units ◽  
Time Integral ◽  
Cord Injury ◽  
Force Time ◽  
And Control ◽  
Force Time Integral

The pattern of seven pulses that elicited maximal thenar force was determined for control muscles and those that have been paralyzed chronically by spinal cord injury. For each subject group ( n = 6), the peak force evoked by two pulses occurred at a short interval (5–15 ms; a “doublet”), but higher mean relative forces were achieved in paralyzed versus control muscles (41.4 ± 3.9% vs. 22.7 ± 2.0% maximal). Thereafter, longer intervals evoked peak force in each type of muscle (mean: 35 ± 1 ms, 36 ± 2 ms, respectively). With seven pulses, paralyzed and control muscles reached 76.4 ± 5.6% and 57.0 ± 2.6% maximal force, respectively. These force differences resulted from significantly greater doublet/twitch and doublet/tetanic force ratios in paralyzed (2.73 ± 0.08, 0.35 ± 0.03) compared with control muscles (2.07 ± 0.07, 0.25 ± 0.01). The greater force enhancement produced in paralyzed muscles with two closely spaced pulses may relate to changes in muscle stiffness and calcium metabolism. Peak force-time integrals were also achieved with an initial short interpulse interval, followed by longer intervals. The postdoublet intervals that produced peak force-time integrals in paralyzed and control muscles were longer than those for peak force, however (77 ± 3 ms, 95 ± 4 ms, respectively). These data show that the pulse patterns that maximize force and force-time integral in paralyzed muscles are similar to those that maximize these parameters in single motor units and various whole muscles across species. Thus the changes in neuromuscular properties that occur with chronic paralysis do not strongly influence the pulse pattern that optimizes muscle force or force-time integral.

Energetics of the Frank-Starling effect in rabbit myocardium: economy and efficiency depend on muscle length

2002 ◽  
Vol 283 (1) ◽  
pp. H324-H330 ◽  
Author(s):  
Jeffrey W. Holmes ◽  
Mark Hünlich ◽  
Gerd Hasenfuss
Keyword(s):  
Oxygen Consumption ◽  
Muscle Length ◽  
Published Data ◽  
Average Force ◽  
Time Integral ◽  
Rabbit Myocardium ◽  
Efficiency Increase ◽  
Butanedione Monoxime ◽  
Force Time ◽  
Force Time Integral

We tested the hypothesis that economy and efficiency are independent of length in intact cardiac muscle over its normal working range. We measured force, force-time integral, force-length area, and myocardial oxygen consumption in eight isometrically contracting rabbit right ventricular papillary muscles. 2,3-Butanedione monoxime was used to partition nonbasal oxygen consumption into tension-independent and tension-dependent components. Developed force, force-time integral, and force-length area increased by factors of 2.4, 2.7, and 4.8, respectively, as muscle length was increased from 90% to 100% maximal length, whereas tension-dependent oxygen consumption increased only 1.6-fold. Economy (the ratio of force-time integral to tension-dependent oxygen consumption) increased significantly with muscle length, as did contractile efficiency, the ratio of force-length area to tension-dependent oxygen consumption. The average force-length area-nonbasal oxygen consumption intercept was more than the twice tension-independent oxygen consumption. We conclude that economy and efficiency increase with length in rabbit myocardium. This conclusion is consistent with published data in isolated rabbit and dog hearts but at odds with studies in skinned myocardium.

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