Preventing Ischial Pressure Ulcers: II. Biomechanics

Background:Pressure ulcers (PUs) are common and debilitating wounds that arise when immobilized patients cannot shift their weight. Neuromuscular Electrical Stimulation (NMES) has been investigated for Pressure Ulcer Prevention (PUP) for over 20 years. Historically gluteus maximus (GM) has been considered an important actuator in attempting to redistribute seated pressures through NMES.Methods:Analysis of skeletal biomechanics to quantify the value of GM relative to hamstring hip extensors (HS), using muscle moment models based on torques and rigid body mass estimates from the literature. Surface stimulation experiments (n= 10 + 1,non-paralyzed) to validate model and identify promising stimulation sites and treatment strategies that would approximate healthy biomechanics.Results:Literature values and Rigid Body Analysis estimate: ~63 Nm extensor torque requirement calculated for complete ipsilateral unloading of the buttocks. Muscle Moment Analysis: GM can provide 70% of total hip extensor torque when walking vs. 18% when seated. HS can provide 100 Nm hip extension torque when seated, exceeding 63 Nm requirement. Surface Stimulation: ipsilateral seated interface pressure mean −26% during HS stimulation vs. +16% with GM; peak pressure area −94% HS vs. +213% GM.Conclusions:GM activation reduces disuse atrophy and improves circulation, but appears neither required, nor desired, for unloading when seated. HS stimulation alone should be capable of sufficient unloading. This new proposed approach is explored clinically in companion paper III.

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Preventing Ischial Pressure Ulcers: III. Clinical Pilot Study of Chronic Neuromuscular Electrical Stimulation

Applied Bionics and Biomechanics ◽

10.1155/2011/536583 ◽

2011 ◽

Vol 8 (3-4) ◽

pp. 345-359 ◽

Cited By ~ 3

Author(s):

Hilton M. Kaplan ◽

Lucinda L. Baker ◽

Salah Rubayi ◽

Gerald E. Loeb

Keyword(s):

Electrical Stimulation ◽

Soft Tissue ◽

Pressure Ulcers ◽

Neuromuscular Electrical Stimulation ◽

Gluteus Maximus ◽

Clinical Results ◽

Trophic Factors ◽

Wound Complications ◽

Maximum Pressure ◽

Muscle Groups

Objective:BIONs™ (BIOnic Neurons) are injectable, wireless microstimulators that make chronic BION Active Seating (BAS) possible for pressure ulcer prevention (PUP). Neuromuscular electrical stimulation (NMES) produces skeletal motion and activates trophic factors, counteracting three major etiological mechanisms leading to pressure ulcers (PUs): immobility, soft-tissue atrophy, and ischemia. Companion papers I and II reviewed prior experience with NMES for PUP, and analyzed the biomechanical considerations, respectively. This paper presents a treatment strategy derived from this analysis, and the clinical results of the first three cases.Methods:Two BIONs implanted (one on inferior gluteal nerve to gluteus maximus (GM), and other on sciatic nerve to hamstrings (HS)), in 3 spinal cord injured (SCI) subjects already undergoing gluteal rotation flaps for PUs. BAS using HS when seated, and BION Conditioning (BC) via GM+HS when non-weightbearing. Follow-up: 1 yr, including 6 mo. treatment window (interface pressure mapping; muscle perfusion scans; MRI, X-ray volume assessments).Results:Successfully implanted and activated both desired muscle groups, selectively, in all. No PU recurrences or wound complications. Two subjects completed protocol. Mean results: Interface: contact pressure −10%; maximum pressure −20%; peak pressure area −15%. Vascularity: GM +20%, HS +110%. Perfusion: GM +70%, HS +440%. Muscle volume: GM +14%, HS +31%. Buttock soft-tissue padding: +49%. 1 BION failed; 1 BION rotated under GM.Conclusions:Promising proof-of-concept data supporting the feasibility of implanted microstimulators to achieve sufficiently strong and selective activation of target muscles for PUP. Ultimate goal is prophylactic deployment through bilateral, nonsurgical injection of BIONs in chronically immobile patients.

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Preventing Ischial Pressure Ulcers: I. Review of Neuromuscular Electrical Stimulation

Applied Bionics and Biomechanics ◽

10.1155/2011/934910 ◽

2011 ◽

Vol 8 (3-4) ◽

pp. 323-331

Author(s):

Hilton M. Kaplan ◽

Gerald E. Loeb

Keyword(s):

Blood Flow ◽

Electrical Stimulation ◽

Soft Tissues ◽

Pressure Ulcers ◽

Neuromuscular Electrical Stimulation ◽

Gluteus Maximus ◽

Recurrence Rates ◽

Normal Forces ◽

The Past ◽

Relative Value

Objective:Pressure ulcers (PUs) are common and debilitating wounds that arise when immobilized patients cannot shift their weight. Treatment is expensive and recurrence rates are high. Pathophysiological mechanisms include reduced bulk and perfusion of chronically atrophic muscles as well as prolonged occlusion of blood flow to soft tissues from lack of voluntary postural shifting of body weight. This has suggested that PUs might be prevented by reanimating the paralyzed muscles using neuromuscular electrical stimulation (NMES). A review of the published literature over the past 2 decades is detailed.Outcomes:Historically gluteus maximus (GM) has been an important target for NMES, but results have been difficult to interpret and suitable technology has been lacking.Conclusions:NMES of the buttock muscles appears to be valuable in terms of its trophic effects, improving vascularity and soft tissue bulk. It remains unclear, however, whether GM can actually achieve sufficient unloading of normal forces to permit blood flow in the capillary beds of the skin and muscle. Analysis of the skeletal biomechanics is required to assess the relative value of GM vs. hamstring (HS) hip extensors in this regard.

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The total gluteus maximus rotation and other gluteus maximus musculocutaneous flaps in the treatment of pressure ulcers

British Journal of Plastic Surgery ◽

10.1016/0007-1226(86)90006-8 ◽

1986 ◽

Vol 39 (1) ◽

pp. 66-71 ◽

Cited By ~ 11

Author(s):

Satya Parkash ◽

S. Banerjee

Keyword(s):

Pressure Ulcers ◽

Gluteus Maximus ◽

Musculocutaneous Flaps

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Planar dynamics of a rigid body system with frictional impacts. II. Qualitative analysis and numerical simulations

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2008.0520 ◽

2009 ◽

Vol 465 (2107) ◽

pp. 2267-2292 ◽

Cited By ~ 23

Author(s):

Zhen Zhao ◽

Caishan Liu ◽

Bernard Brogliato

Keyword(s):

Qualitative Analysis ◽

Rigid Body ◽

Numerical Simulations ◽

Contact Point ◽

Impulsive Differential Equations ◽

Companion Paper ◽

Rigid Body Dynamics ◽

Drift Motion ◽

Contact Points ◽

Static Coefficient Of Friction

The objective of this paper is to implement and test the theory presented in a companion paper for the non-smooth dynamics exhibited in a bouncing dimer. Our approach revolves around the use of rigid body dynamics theory combined with constraint equations from the Coulomb's frictional law and the complementarity condition to identify the contact status of each contacting point. A set of impulsive differential equations based on Darboux–Keller shock dynamics is established that can deal with the complex behaviours involved in multiple collisions, such as the frictional effects, the local dissipation of energy at each contact point, and the dispersion of energy among various contact points. The paper will revisit the experimental phenomena found in Dorbolo et al . ( Dorbolo et al . 2005 Phys. Rev. Lett. 95 , 044101), and then present a qualitative analysis based on the theory proposed in part I. The value of the static coefficient of friction between the plate and the dimer is successfully estimated, and found to be responsible for the formation of the drift motion of the bouncing dimer. Plenty of numerical simulations are carried out, and precise agreements are obtained by the comparisons with the experimental results.

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Estimation of Local Ice Pressure Using Up-Crossing Rate

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.4000403 ◽

2010 ◽

Vol 132 (3) ◽

Cited By ~ 4

Author(s):

Chuanke Li ◽

Ian J. Jordaan ◽

Rocky S. Taylor

Keyword(s):

Probabilistic Method ◽

Companion Paper ◽

Offshore Structures ◽

Maximum Pressure ◽

Local Pressure ◽

Data Set ◽

Pressure Area ◽

Rate Method ◽

Ice Pressure ◽

Maximum Method

Ice load estimation is required in the design of ships and offshore structures for arctic and subarctic conditions. This paper focuses on the estimation of local ice pressures. The “event-maximum” method for local ice pressure analysis is a probabilistic method based on the maximum pressure of a given event; other local peaks in the data are not included. To study how this may affect local ice pressure estimates, a new probabilistic method based on the up-crossing rate was developed. Field data from 1982 Polar Sea arctic trials in the Beaufort Sea are processed as a time series. Up-crossing rates at different local pressure levels are obtained for local areas of interest. A relationship between up-crossing rate and local pressure-area results is established. Results from the analysis of full-scale data using the event-maximum method are presented for the selected data set; a more comprehensive set of results for the analysis of available ship-ice interaction data is presented in a companion paper. For a sample case, local ice pressure estimates obtained using the up-crossing rate method are compared with results obtained using the event-maximum method. The local pressure-area relationship is found to be similar for both the up-crossing rate method and the event-maximum method. For design curves based on the data set considered, estimates using the event-maximum method were more conservative than those obtained using the up-crossing rate method. The up-crossing rate approach is promising; analysis of additional data sets is recommended to allow broader comparison of the methods.

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Effects of electrode size and placement on comfort and efficiency during low-intensity neuromuscular electrical stimulation of quadriceps, hamstrings and gluteal muscles

BMC Sports Science Medicine and Rehabilitation ◽

10.1186/s13102-022-00403-7 ◽

2022 ◽

Vol 14 (1) ◽

Author(s):

J. Flodin ◽

R. Juthberg ◽

P. W. Ackermann

Keyword(s):

Electrical Stimulation ◽

Muscle Contraction ◽

Current Density ◽

Rating Scale ◽

Numerical Rating Scale ◽

Neuromuscular Electrical Stimulation ◽

Gluteus Maximus ◽

Major Drawback ◽

Electrode Size ◽

Low Intensity

Abstract Background Neuromuscular electrical stimulation (NMES) may prevent muscle atrophy, accelerate rehabilitation and enhance blood circulation. Yet, one major drawback is that patient compliance is impeded by the discomfort experienced. It is well-known that the size and placement of electrodes affect the comfort and effect during high-intensity NMES. However, during low-intensity NMES the effects of electrode size/placement are mostly unknown. Therefore, the purpose of this study was to investigate how electrode size and pragmatic placement affect comfort and effect of low-intensity NMES in the thigh and gluteal muscles. Methods On 15 healthy participants, NMES-intensity (mA) was increased until visible muscle contraction, applied with three electrode sizes (2 × 2 cm, 5 × 5 cm, 5 × 9 cm), in three different configurations on quadriceps and hamstrings (short-transverse (ST), long-transverse (LT), longitudinal (L)) and two configurations on gluteus maximus (short-longitudinal (SL) and long-longitudinal (LL)). Current–density (mA/cm2) required for contraction was calculated for each electrode size. Comfort was assessed with a numerical rating scale (NRS, 0–10). Significance was set to p < 0.05 and values were expressed as median (inter-quartile range). Results On quadriceps the LT-placement exhibited significantly better comfort and lower current intensity than the ST- and L-placements. On hamstrings the L-placement resulted in the best comfort together with the lowest intensity. On gluteus maximus the LL-placement demonstrated better comfort and required less intensity than SL-placement. On all muscles, the 5 × 5 cm and 5 × 9 cm electrodes were significantly more comfortable and required less current–density for contraction than the 2 × 2 cm electrode. Conclusion During low-intensity NMES-treatment, an optimized electrode size and practical placement on each individual muscle of quadriceps, hamstrings and gluteals is crucial for comfort and intensity needed for muscle contraction.

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A Descriptive, Retrospective Study of Using an Oblique Downward-design Gluteus Maximus Myocutaneous Flap for Reconstruction of Ischial Pressure Ulcers

Wound Management & Prevention ◽

10.25270/owm.2018.3.4044 ◽

2018 ◽

Vol 64 (3) ◽

pp. 40-44

Author(s):

Chang-Yi Chou ◽

Yu=shan Sun ◽

Yu-jen Shih ◽

Yuan-Sheng Tzang ◽

Shun-Chang Chang ◽

...

Keyword(s):

Retrospective Study ◽

Pressure Ulcers ◽

Myocutaneous Flap ◽

Gluteus Maximus ◽

Gluteus Maximus Myocutaneous Flap

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Modeling of Elastically Coupled Bodies: Part II—Exponential and Generalized Coordinate Methods

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2801492 ◽

1998 ◽

Vol 120 (4) ◽

pp. 501-506 ◽

Cited By ~ 15

Author(s):

Ernest D. Fasse ◽

Peter C. Breedveld

Keyword(s):

Rigid Body ◽

Constitutive Equations ◽

Companion Paper ◽

Rigid Bodies ◽

Geometric Modelling ◽

Geometric Method ◽

Generalized Coordinate

This paper looks at spatio-geometric modelling of elastically coupled rigid bodies. Two methods are presented. In the first method constitutive equations are derived by associating rigid body displacements with twist displacements and then generating wrenches proportional to the twist displacements. In the second method consistitutive equations are derived by associating rigid body displacements with generalized coordinate displacements, generating generalized forces proportional to the displacements, and then computing corresponding wrenches. The application of these methods and the geometric method presented in the companion paper are illustrated in a nontrivial example.

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