Fabian E. Pollo

Effects of lateral-wedged insoles on kinetics at the knee.

Lateral-wedged insoles have been shown to help clinically alleviate pain associated with medial compartment osteoarthritis. This study analyzed the effects of lateral-wedged insoles on the gait and medial knee compartment load of 17 healthy subjects. Three-dimensional gait analysis was performed for each subject with and without wearing a 5° lateral-wedged insole. Subjects walked at a constant velocity for both conditions. A motion analysis system and force plate were used to calculate temporal and spatial parameters, joint angles, moments, and powers. An analytical model was developed to estimate medial compartment loads at the knee for each subject during both conditions. Results were compared with a Students paired t test. There were no significant differences in temporal and spatial parameters, joint angles at the hip, knee, and ankle, or kinetics at the hip and ankle. However, the external varus moment and estimated medial compartment load at the knee were reduced significantly with the addition of the lateral-wedged insole. These results suggest that the pain relief and improvement in function reported by patients with osteoarthritis while using lateral-wedged insoles may be achieved by a reduction in external varus moment and medial compartment load.

First Metatarsophalangeal Arthrodesis: A Clinical, Pedobarographic and Gait Analysis Study

This study investigated the results of first metatarsophalangeal (MTP) arthrodesis in terms of clinical outcome measures, plantar pressure distribution, and gait patterns. Ten feet in nine patients with severe hallux rigidus (HR) who underwent first MTP arthrodesis were studied. The preoperative evaluation included a subjective questionnaire, physical exam, AOFAS hallux score, radiographs and dynamic pedobarography (EMED). At follow-up (average 34 months) these were repeated, and gait analysis studies were obtained. Patients showed significant clinical improvement based on the subjective criteria. The mean AOFAS score improved from 38 preoperatively to 90 postoperatively. Postoperative EMED analysis showed restoration of the weightbearing function of the first ray, with greater maximum force carried by the distal hallux at toe-off. Kinematic and kinetic gait analysis from each patients operative limb were compared to the unaffected contralateral limb and to age- and sex-matched healthy subjects. The kinematic data indicated a significantly shorter step length with some loss in ankle plantar flexion at toe-off on the fused side. The kinetic data indicated a reduction in both ankle torque and ankle power at push-off. Clinical results indicated effective pain relief and a high level of patient satisfaction, consistent with previous reports in patients with symptomatic Hallux Rigidus.

Functional Outcome of Arthrodesis of the First Metatarsophalangeal Joint Using Parallel Screw Fixation

Background: Arthrodesis of the first metatarsophalangeal (MTP) joint is a reliable procedure for a painful hallux. Most studies focus on the surgical results rather than the functional outcome for the patient. Therefore, we examined the effects of first MTP joint arthrodesis on activities of daily living and recreational activities. Methods: Fifty-three patients (60 feet) who had isolated arthrodesis of the first (MTP) joint using a parallel screw fixation technique were evaluated for the functional outcome after the surgery to determine the effect of the arthrodesis on the activities of daily living and on recreational sports and exercise. Results: Fusion was achieved in all patients; all but three stated that they would have the surgery again. Postoperative pain scores evaluated using the Visual Analogue Scale indicated effective pain relief. High levels of function were demonstrated in this group of patients. Conclusion: Arthrodesis of the first MTP joint is not only a successful surgical technique for relief of pain and correction of deformity but also allows a high level of function in everyday life and in recreational activities.

Locomotor Treadmill Training With Partial Body-Weight Support Before Overground Gait in Adults With Acute Stroke : A Pilot Study

OBJECTIVE To investigate the impact of locomotor treadmill training with partial body-weight support (BWS) before the initiation of overground gait for adults less than 6 weeks poststroke. DESIGN Parallel group, posttest only. SETTING Inpatient rehabilitation center. PARTICIPANTS Adults after first stroke admitted to an inpatient rehabilitation unit: treadmill group (n=7) and comparison group (n=7). INTERVENTIONS Locomotor treadmill training with partial BWS or traditional gait training methods. MAIN OUTCOME MEASURES Gait kinematics, symmetry, velocity, and endurance at least 6 months postinsult. RESULTS Data from 3-dimensional gait analysis and 6-minute walk test (6MWT) supported improved gait for adults postacute stroke who practiced gait on a treadmill before walking over ground. Gait analysis showed increased knee flexion during swing and absence of knee hyperextension in stance for the treadmill group. In addition, more normal ankle kinematics at initial contact and terminal stance were observed in the treadmill group. Improved gait symmetry in the treadmill group was confirmed by measures of single support time, hip flexion at initial contact, maximum knee flexion, and maximum knee extension during stance. The treadmill group also walked further and faster in the 6MWT than the comparison group. CONCLUSIONS Application of locomotor treadmill training with partial BWS before overground gait training may be more effective in establishing symmetric and efficient gait in adults postacute stroke than traditional gait training methods in acute rehabilitation.

Prospective gait analysis in patients with first metatarsophalangeal joint arthrodesis for hallux rigidus.

Background: Arthrodesis of the first metatarsophalangeal (MTP) joint is a common procedure with a proven long-term success rate. However, there is limited scientific information on its functional results. There is little data in the literature about changes in gait parameters after first MTP joint arthrodesis. The purpose of this study was to objectively evaluate the effects of first MTP joint arthrodesis on gait. Methods: Twenty-three patients with symptomatic hallux rigidus refractory to nonoperative treatment were treated with first MTP joint arthrodesis. A prospective gait analysis study was performed on all patients at an average of 8.6 days before surgery and then again at least 1 year postoperatively. Preoperative and postoperative data from the patients were compared to determine differences in clinically relevant temporal-spatial, kinematic, and kinetic parameters of gait. Results: There were three statistically significant changes in gait: increases in maximal ankle push-off power and single-limb support time on the involved extremity, and a decrease in step width. Conclusions: First MTP joint arthrodesis produces objective improvement in propulsive power, weightbearing function of the foot, and stability during gait.

Knee bracing for unicompartmental osteoarthritis.

Unicompartmental osteoarthritis of the knee affects millions of individuals. Most nonsurgical management of this progressive disease is primarily directed at reducing inflammation and pain with medication. Evidence supports the clinical efficacy of bracing for managing osteoarthritis of the knee. In some patients, bracing significantly reduces pain, increases function, and reduces excessive loading to the damaged compartment. A variety of health and functional status instruments, as well as radiologic techniques and biomechanical investigations, has been used to evaluate the unloading capabilities of these braces. Although changes in angulation are relatively minimal, the braces have been shown to load share and thus reduce the stresses in the degenerated medial compartment of the knee.

Preliminary Gait Analysis Results After Posterior Tibial Tendon Reconstruction: A Prospective Study:

The purpose of this study was to investigate the effect on gait in patients who underwent reconstruction for stage II posterior tibial tendon (PTT) dysfunction. Twelve patients with stage II PTT dysfunction underwent surgical reconstruction consisting of debridement of the posterior tibial tendon, flexor digitorum longus tendon transfer to the navicular tuberosity, medial displacement calcaneal osteotomy, and spring ligament reconstruction. Midfoot arthrodesis was performed in six patients and gastrocnemius recession in three. Gait analysis was performed 2 weeks prior to surgery and 1 year postoperatively. Preoperative and postoperative data were compared to determine differences in temporal-spatial parameters, lower limb kinematics, and ankle push-off power. Step length for the operated side increased from 52.6 ± 9.6 cm before the surgery to 57.5 ± 7.1 cm after the surgery (p = .048). Cadence improved from 100.2 ± 10.7 steps/min to 109.1 ± 8.5 steps/min (p = .05), thus increasing velocity from 87.6 ± 22.6 cm/s to 103.4 ± 15.9 cm/s (p = .042). Single support percentage was unchanged. Maximum sagittal ankle joint power at push-off increased from 0.79 ± 0.35 W before surgery to 1.2 ± 0.5 W after surgery (p = .042). There were statistically significant improvements in all radiographic parameters studied. This is the first prospective study to evaluate the in vivo effects on gait in patients undergoing this common surgical procedure. Analysis demonstrated statistically significant improvement in kinetic and kinematic parameters of gait function.

Plantar Pressures in Fiberglass Total Contact Casts vs. a New Diabetic Walking Boot

The objective of this study was to determine in healthy individuals whether the Bledsoe Diabetic Conformer Boot reduces plantar pressures as well as a fiberglass total contact cast. Eighteen normal subjects, without any prior foot or ankle problems, were recruited for this study. Plantar pressures were measured using the Novel Pedar™ in-shoe pressure measurement system. The results of this study demonstrate that in individuals without foot deformities, the Bledsoe Diabetic Conformer Boot™ performs as well as, and in many parameters, even better than a fiberglass total contact cast with respect to reducing the forces and pressures on the plantar surface of the foot.

Unloading Mechanism in the Total Contact Cast

Background: The effectiveness of total contact casts is postulated to be due to the reduction of plantar pressure. We investigated plantar loads to evaluate the mechanism by which total contact casts off-load the plantar surface of the foot to determine if it is the intimate molding of the weightbearing plantar surface or if a below-knee cast is necessary. Methods: Plantar pressures and forces in a total contact cast (TCC) were recorded in 12 healthy subjects, using the Pedar® (Novel GmbH, Munich, Germany) pedobarographic system. The measurements were repeated after removal of the ‘shank’ portion of the cast (proximal to malleoli), leaving in effect, a well-molded shoe-cast (SC). Measurements included average force and peak pressure. All parameters were measured under two different loading conditions: single-leg standing balanced on the casted limb and over-ground walking. To assess the contribution of calf geometry, the ‘calf ratio’ was calculated by dividing the largest by the smallest circumferences of the calf. All parameters were compared between TCC and SC for each subject in each of the two conditions. Paired t-tests were used to evaluate significance, which was set at a level of p < 0.006 due to the Bonferroni Correction. Results: Removal of the shank portion of the TCC significantly increased the average plantar force by 31% during walking. The force only increased 9% during standing, which was not significant. Peak pressure increased 53% after removal of the shank portion of the TCC during walking. Peak pressure was not significantly different during standing on one limb. No correlation was found between the calf ratio and the magnitude of change in the measured values. Conclusions: These results help to partially explain the widely recognized clinical observation that molded insoles and shoes, no matter how well conformed to the foot, do not reduce plantar loads as effectively as a total contact cast. The mechanism appears to be a critical unloading function of the proximal, ‘shank’ portion of the cast, presumably due to reduction in ankle motion.

The effect of ankle position on plantar pressure in a short leg walking boot.

Short leg walking boots have been shown to be an effective alternative to total contact casting for the reduction of plantar pressure. Conventional theory indicates that placing the ankle in different positions may affect the plantar pressure and ultimately the healing time for a plantar ulcer. This study attempted to determine the changes in plantar pressures due to alterations in the position of the ankle angle in a walking boot. Thirteen healthy subjects were recruited and tested with an insole pressure measurement system. The result demonstrated that small changes in ankle position in dorsiflexion or plantarflexion have a significant impact on resulting forefoot and hindfoot plantar pressures while walking in a prefabricated boot.