This study examined the effects of two designs of rigid foot orthoses on plantar pressure measurements and identified differences between the devices. While wearing modified Root- and Blake-style orthoses, 27 subjects were examined with the Electrodynogram (EDG) in-shoe pressure measurement system. Reliability testing was performed on the EDG data. Significant changes were observed in the temporal parameters of gait when subjects wore the orthoses. When the devices were used, the duration of some of the components of stance phase was altered, and the initiation of loading beneath the medial forefoot was delayed. A reduction in the total duration of loading at discrete sites beneath the heel and forefoot was also observed. The effects of the two orthoses were similar, with only small differences observed between the devices. (J Am Podiatr Med Assoc 91(4): 184-193, 2001)
Background: Plantar first metatarsal ulcerations pose a difficult challenge to clinicians. Etiologies vary and include first metatarsal declination, cavus foot deformity, equinus contracture, and hallux limitus/rigidus. Our pragmatic, sequential approach to the multiple contributing etiologies of increased plantar pressure sub–first metatarsal can be addressed through minimal skin incisions.
Methods: A retrospective review was performed for patients with surgically treated preulcerations or ulcerations sub–first metatarsal head. All of the patients underwent a dorsiflexory wedge osteotomy, and the need for each additional procedure was independently assessed. Equinus contracture was treated with Achilles tendon lengthening, cavovarus deformity was mitigated with Steindler stripping, and plantarflexed first ray was treated with dorsiflexory wedge osteotomy.
Results: Eight patients underwent our pragmatic, sequential approach for increased plantar pressure sub–first metatarsal, four with preoperative ulcerations and four with preoperative hyperkeratotic preulcerative lesions. The preoperative ulcerations were present for an average of 25.43 weeks (range, 6.00–72.86 weeks), with an average size of 0.19 cm3 (median, 0.04 cm3). Procedure breakdown was as follows: eight first metatarsal osteotomies, four Achilles tendon lengthenings, and six Steindler strippings. Postoperatively, all eight patients returned to full ambulation, and the four ulcerations healed at an average of 24 days (range, 15–38 days). New ulceration occurred in one patient, and postoperative infection occurred in one patient. There were no ulceration recurrences, dehiscence of surgical sites, or minor or major amputations.
Conclusions: The outcomes in patients surgically treated for increased plantar first metatarsal head pressure were evaluated. This case series demonstrates that our pragmatic, sequential approach yields positive results. In diabetic or high-risk patients, it is our treatment algorithm of choice for increased plantar first metatarsal pressure.
Background: This study investigated the effects of two low-Dye and two high-Dye strapping techniques that are commonly used to treat pronatory sequelae.
Methods: Plantar pressure distribution in normal adults with a pronated foot type was assessed with a commercially available pressure platform system. Twenty study participants first walked across the platform barefoot and then with each of the four strapping conditions applied. The footprints were averaged and divided into seven areas for analysis.
Results: Paired t tests found significant differences between the barefoot and strapping conditions. Overall, there was a general lateralization of pressures indicating an antipronation effect from all strapping conditions. Low-Dye strap 2, used to limit the degree of calcaneal eversion, produced the most significant changes at the foot pressure areas analyzed.
Conclusions: The data reported in this study suggest that the four strapping techniques offer different levels of control, and this should be considered during the decision-making process and clinical management of pronatory conditions. It was the contention of this study that low-Dye strap 2 was the most effective strapping technique to control foot mechanics associated with a pronated foot type. (J Am Podiatr Med Assoc 99(5): 391–398, 2009)
Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU.
Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout.
The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature.
The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.
Abnormal plantar pressures are the hallmark characteristic of several conditions and pathologic abnormalities. Pressure platforms allow for quick and accurate screening of patients and help guide clinical treatment. However, it is essential to evaluate the reliability and repeatability of these devices before making clinical decisions. The purpose of this study was to determine the reliability of the EPS-Platform during static and dynamic activities.
Fifty-six healthy individuals stood and walked onto the pressure platform. Five trials were performed during two separate testing sessions to determine intrasession and intersession reliability. Pressure data were obtained and several variables of interest were calculated for intrasession and intersession reliability using intraclass correlation coefficients (ICCs), SEM, percent error, and coefficient of variation.
Static and dynamic intrasession and intersession reliability produced moderate-to-excellent ICCs, low SEMs, low percent errors, and low coefficients of variation. Static trials had higher ICCs, lower percent errors, and lower coefficients of variation compared with dynamic trials. Intersession reliability also had higher ICCs, lower percent errors, and lower coefficients of variation compared with intrasession reliability.
This study demonstrates that the EPS-Platform is a reliable device for collecting gait plantar pressures. Static trials produce better reliability, most likely owing to the large inherent variability during dynamic gait. Intersession reliability was higher than intrasession reliability owing to the intersession measures being calculated with an average of five trials. By averaging the trials, the variability of gait is decreased, and this improves the accuracy of the results. These results can be used as the basis for future studies and to determine a priori sample sizes for investigations that use the EPS-Platform. (J Am Podiatr Med Assoc 103(3): 197–203, 2013)
Any pathomechanical change in the foot or ankle is expected to cause adverse biomechanical effects on the lumbopelvic region. However, no objective data can be found in the literature regarding the effects of musculus transversus abdominis (mTrA) and musculus lumbar multifidus (mLM), which are effective muscles in lumbopelvic motor control, or regarding the extent of their effects.
Sixty-four healthy young adults were assessed by a physiotherapist (C.K.) experienced in treating feet and a radiologist (Y.D.) specialized in muscular imaging. In the determination of biomechanical properties of the foot, the navicular drop test (NDT), Foot Posture Index (FPI), pedobarographic plantar pressure analysis, and isokinetic strength dynamometer measurements were used in determining the strength of the muscles around the ankle. Ultrasonographic imaging was used to determine mTrA and mLM thicknesses.
Significant correlation was found between NDT results and mTrA and mLM thicknesses (P < .05) and between FPI results and mTrA thicknesses (P < .05). As the peak pressure of the foot medial line increased, mTrA and mLM thicknesses decreased (P < .05). Although dorsiflexion muscle strength was also effective, mTrA and mLM thicknesses were found to increase especially as plantarflexion muscle strength increased (P < .05).
These results show that the biomechanical and musculoskeletal properties of the foot-ankle are associated with lumbopelvic stability.
Weakness of the toe flexor muscles has been attributed to the development of toe pathologies, and it responds well in the clinic to toe grip exercises. However, it is unknown whether exercising the toe flexor muscles improves the ability to grip and alter function. The aim of this study was to assess the effect of toe flexor exercises on apical plantar pressure, as a measure of grip, while seated and during gait.
Twenty-three individuals with no known toe pathologies were recruited. Static peak pressure, time spent at peak pressure, and pressure-time integral while seated, as well as dynamic forefoot maximal force, contact area, and percentage contact time, were recorded before and after exercise. Toe grip exercises with a therapy ball were completed daily for 6 weeks.
Static peak pressure significantly increased after exercise on the apex of the second and third digits, as did the pressure-time integral. Dynamic peak force and contact area did not alter after exercise around the metatarsals and toes, yet percentage contact time significantly increased for each metatarsal after completing daily toe grip exercises.
Exercises to improve the grip ability of the toes increased the static peak pressure on the apex of the second and third digits as well as the percentage contact time of the metatarsals during gait. The ability to increase apical peak pressure and contact time after exercises could assist in improving forefoot stability and gait efficiency and in reducing toe pathology progression.
Altered foot loading during weightbearing is suggested to play a role in the development of patellofemoral pain (PFP). This study aimed to determine foot-loading characteristics associated with PFP by assessing center of pressure (COP) during single-limb loading in individuals with PFP compared with noninjured controls.
Thirty recreationally active patients with PFP and 30 noninjured control participants had barefoot plantar pressure assessed during single-limb squats (SLSs) from which COP parameters (COP velocity and COP index) were obtained. Groups were compared using independent t tests.
Individuals with PFP demonstrated a greater COP index (P = .042), indicating a more lateral foot-loading pattern, and exhibited increased overall COP velocity (P = .013) and anteroposterior COP velocity during SLSs compared with control participants (P = .033).
Greater lateral foot loading and increased COP velocity during SLSs demonstrated by individuals with PFP may indicate reduced dynamic balance in this patient group, which may be implicated in the development of PFP.
Background: Individuals with diabetic neuropathy may experience plantar ulcers and postural instability. Although use of an insole with arch support has the potential to decrease the incidence of plantar ulcers, the choice of proper design and material density concerning postural stability is challenging. The objective of this pilot study was to conduct a preliminary evaluation of the immediate effects of custom-made ethyl vinyl acetate insoles with arch support and Shore A values of 30 or 50 on static balance in patients with diabetes and neuropathic foot/feet.
Methods: Ten women with diabetes participated in this study. Static balance was analyzed while in double-limb standing with eyes closed and eyes open and while standing on a dominant limb with eyes open wearing shoes only and wearing shoes and insoles with Shore A values of 30 and 50.
Results: With insole, the mean values of center of pressure excursions decreased significantly while standing on double limbs with eyes closed. The improvement in static balance was greater while using the insole with greater density; however, the difference was not statistically significant.
Conclusions: An insole with arch support made of ethyl vinyl acetate Shore A of 30 and 50, which could decrease plantar pressure concentration, had no negative effect on the static balance of diabetes. Therefore, further research on the long-term effects of such insoles on the static balance of diabetes is suggested.
Rheumatoid arthritis (RA) often affects feet with progressive pathologic changes to foot morphology and pressure distribution. Studies in RA suggest that reductions in forefoot peak pressures can reduce pain. We investigated the effects of off-the-shelf foot orthoses on plantar foot pressures in patients with early RA.
Thirty-five patients with early RA were recorded walking. Variables measured were forefoot peak plantar pressure (PPPft), forefoot pressure-time integral (PTIft), and hallux and lesser toe and midfoot contact areas. Patients were analyzed while walking barefoot, with shoes, and with shoes and foot orthoses. Measurements were taken at baseline and at 3 and 6 months.
There were significantly increased PPPft values between barefoot and shod and between barefoot and orthoses (P < .01). However, there was a significant reduction in PPPft during the 6 months with orthoses compared with shoes only (P < .01). Foot orthoses significantly reduced PTIft over 6 months (P < .01). Results also demonstrated a significant increase in hallux and lesser toe (P < .01) and midfoot (P < .01) contact areas during the 6 months with foot orthoses.
In patients with early RA, off-the-shelf foot orthoses cause a significant reduction of 22% in PPPft and 14% in PTIft as soon as insoles are worn compared with shod. Further reductions for orthoses compared with baseline were found by 3 months (15% in PPPft and 14% in PTIft) and 6 months (33% in PPPft and 33% in PTIft). These findings could contribute to reductions in foot pain.