Lower Extremity Pathology Research Articles

Five-Toed Socks with Grippers on the Foot Sole Improve Dynamic Postural Control in Healthy Individuals

Socks are standard equipment in most forms of physical activity. In Japan, versions of five-toed socks with grippers are being worn by athletes and are gaining popularity because of the perceived improvements in balance that result from their wear. However, no scientific research has been conducted to examine the effectiveness of the socks. PURPOSE: To compare the effectiveness of five-toed socks with grippers on the sole in healthy individuals on dynamic postural control. METHODS: Twenty-five, healthy, physically active subjects (7 males, 18 females; 22.28±3.22 yrs, 168.40±8.88 cm, 70.02±14.28 kg) reported to the laboratory for three testing sessions, separated by 1 week apart, during which dynamic postural control was assessed with the Star Excursion Balance Test (SEBT) performed wearing three sock conditions: five-toed socks with grippers (FS), regular socks (RS), and no socks (NS). Subjects performed the anterior, posterior lateral, and posterior medial directions of the SEBT while standing on the dominant limb (leg used to stand on while kicking a ball). The sock conditions and order of reaching directions were randomized. The dependent variables were the maximum reaching distance normalized to the leg length of the stance/testing leg (%MAXD) in each of the anterior, posteriormedial, and posteriorlateral directions. The independent variable was sock condition (FS, RS, and NS). For each dependent variable, a one-way repeated measures ANOVA was performed and Tukey's testing was used for post hoc analyses. Significance was set a priori at p<0.05. RESULTS: Significant one way interactions existed in the anterior (F2,22 =3.598; p=0.035) and posterior lateral direction of the SEBT (F2,22 = 6.729; p=0.003). For the anterior direction, the FS condition (0.821±0.069) displayed significantly higher %MAXD values compared to the NS condition (0.802±0.075). For the posterior lateral direction, the FS condition (0.818±0.106) displayed significantly higher %MAXD values compared to the both RS (0.779±0.106) and NS (0.788±0.111) conditions. CONCLUSIONS: These results indicate that the FS condition was associated with increased dynamic postural stability when compared to the RS and NS conditions. Further research should focus on the effects of the FS on postural control in patients with lower extremity pathology.

Effects of semi-customized orthotics on static and dynamic postural control: AAPSM session

Foot orthoses for a person with abnormal foot mechanics have been shown to be effective in clinical setting for the management of lower extremity pathologies. Previous studies have shown that orthotics and low-dye taping have both a biomechanical and neuromuscular effect. Purpose: The purposes of this study were (1) to identify the immediate effects of custom thermoformed orthotics on static and dynamic postural control and planter pressure during walking and (2) to identify the long-term effects of the orthotics on static and dynamic postural control in healthy female college students with hyperpronated feet.

Pedobarographic assessment of 17 patients with ankle arthrodesis

Aim The aim of this study is to compare and analyse the changes in plantar pressure whilst walking, in patients with ankle arthrodesis by means of kinetic and kinematical motion analysis and plantar support studies. Patients and method We studied 17 patients (14 males and 3 females) with posttraumatic ankle arthrodesis (13 right side and 4 left side) with a minimum follow up of three years (3–9 years). There were no other associated lower extremity pathologies. The mean age was 40 years (26–54 yrs.) and mean weight 89kg (54–117kg). A physical examination and pedography was performed (Emed ®, Novel, Munich, Germany). The foot was divided into 6 zones and we compared the fused one with the control. Results The fused ankle had lower total pressures, vertical forces and support area compared to the non-fused. On the other hand, the support time was greater in the fused ankle. Pressures on the heel, midfoot and forefoot were higher in the fused side. We confirmed higher pressures in the forefoot and toes in the external and central part of the fused side. Conclusion Pressures on the midfoot and internal and central part of the forefoot are greater after an ankle arthrodesis due to changes in the plantar arch that release support from the heel and the first toe.

Intersession Reliability of Hoffmann Reflex Gain and Presynaptic Inhibition in the Human Soleus Muscle

Hayes BT, Hicks-Little CA, Harter RA, Widrick JJ, Hoffman MA. Intersession reliability of Hoffmann reflex gain and presynaptic inhibition in the human soleus muscle. Objective To determine the day-to-day reliability of Hoffmann reflex (H-reflex) gain and presynaptic inhibition of spinal reflexes in the human soleus muscle. Design Controlled trial. Setting Research laboratory. Participants Volunteers (N=30; mean ± SD age, 23.4±3.9y; height, 175.64±10.87cm; mass, 84.50±24.18kg) with no history of lower extremity pathology and/or injury participated. Interventions Subjects lay prone with the head, shoulders, arms, and hips supported in a static position by a massage body pillow and the ankle positioned at 90°. Recording electrodes were placed over the soleus and tibialis anterior muscle bellies, and the stimulating electrodes were positioned over the tibial nerve in the popliteal space and the common peroneal nerve near the fibular head. Main Outcome Measures The H-reflex and motor wave recruitment curves were then measured and recorded. Presynaptic inhibition was also assessed in the soleus muscle, and a conditioning stimulation of the common peroneal nerve (1 × motor threshold = motor threshold) was used prior to soleus H-reflex measurement. Two testing sessions took place between 2 and 7 days, and each session occurred at the same time of day. Results Assessments of H-reflex gain and presynaptic inhibition yielded test-retest reliability of R equal to . 95 and .91, respectively. Conclusions Measures of presynaptic inhibition and H-reflex gain (H slope/M slope) in the human soleus muscle are consistent and reliable day to day.

The effect on neuromuscular stability, performance, multi-joint coordination and proprioception of barefoot, taping or preventative bracing

Objective The objective of this study was to assess the effects of taping and preventive bracing on functional balance, jumping performance, multi-joint coordination and proprioception on comparison to barefoot and each other. Design Controlled trial as an experiment with the independent variable testing in 3 trials: control (barefooted), preventive bracing, and taping. Setting The sports physiotherapy research laboratory. Participants Twenty physically active male university students aged between 20 and 28 who had been free from lower extremity pathology for 12 months and had no previous history of ankle sprain served as participants. Main outcome measures Single leg balance (s), jumping performance (cm), coordination and proprioception assessments by the Functional Squat System. The software automatically calculated the absolute average error (cm) and the standard deviation (SD) of the average error. Average errors were independently quantified as a function of the action mode (concentric versus eccentric) and of the lower limb (dominant versus non-dominant). Results There was no significant difference among the groups for balance tests ( p > 0.05). For vertical jump performance of bilateral and the dominant leg there were significant differences that the barefoot group had better results compared to the other groups ( p = 0.059; 0.017). According to the coordination results of Functional Squat System participants were better in brace and tape situations since the deviations were less for all concentric and eccentric positions. Deviation results for the proprioception test were different for first visual and non-visual deviations for dominant leg ( p < 0.05). Conclusion In conclusion, bracing and taping may play an important role in preventing injury or rehabilitation of the injured ankle by improving concentric and eccentric coordination, proprioception with the ability of reproducing motion in closed kinetic chain while decreasing vertical jump performance. No superiority of brace over tape or vice versa was found in this study.

Effects of Neuromuscular Training on the Reaction Time and Electromechanical Delay of the Peroneus Longus Muscle

Linford CW, Hopkins JT, Schulthies SS, Freland B, Draper DO, Hunter I. Effects of neuromuscular training on the reaction time and electromechanical delay of the peroneus longus muscle. Objective To examine the influence of a 6-week neuromuscular training program on the electromechanical delay and reaction time of the peroneus longus muscle. Design A 2×2 pre-post factorial design. Setting Human performance research center biomechanics laboratory. Participants Thirty-six healthy, physically active, college-age subjects were recruited for this study and 26 completed it. There were 5 men and 8 women in the treatment group (mean age ± standard deviation, 21.9±2.1y; height, 173.7±11.1cm; weight, 67.4±17.8kg) and 6 men and 7 women in the control group (age, 21.8±2.3y; height, 173.7±11.9cm; weight, 70.8±19.4kg). Subjects were not currently experiencing any lower-extremity pathology and had no history of injuries requiring treatment to either lower extremity. Interventions Subjects in the treatment group completed a 6-week neuromuscular training program involving various therapeutic exercises. Subjects in the control group were asked to continue their normal physical activity during the 6-week period. Main Outcome Measures The electromechanical delay of the peroneus longus was determined by the onset of force contribution after artificial activation, as measured by electromyographic and forceplate data. Reaction time was measured after a perturbation during walking. Data were analyzed using two 2×2 analyses of covariance (covariate pretest score). Group (treatment, control) and sex (male, female) were between-subject factors. Results Neuromuscular training caused a decrease in reaction time to perturbation during walking compared with controls (F=4.030, P=.029), while there was a trend toward an increase in electromechanical delay (F=4.227, P=.052). There was no significant difference between sexes or the interaction of sex and treatment in either reaction time or electromechanical delay. Conclusions The 6-week training program significantly reduced reaction time of the peroneus longus muscle in healthy subjects. Neuromuscular training may have a beneficial effect on improving dynamic restraint during activity.

Operation Iraqi Freedom: The Landstuhl Regional Medical Center Experience

Landstuhl Regional Medical Center, Germany, the only American medical center in Europe, received approximately 80% of American military patients evacuated out of theater during the first 4 months of Operation Iraqi Freedom. 1236 patients arrived at Landstuhl Regional Medical Center from the beginning of Operation Iraqi Freedom until May 15, 2003, consisting of 256 battle casualties (20.7%), 510 injury patients (41.3%), and 470 disease patients (38.0%). Retrospective record reviews were done on all battle casualties, as well as all disease and injury patients with a musculoskeletal diagnosis. Of the battle casualty patients, 68.4% suffered an extremity injury--a percentage that is consistent with that from prior wars. 52.8% had a lower extremity injury and 21.5% had a foot or ankle injury. Additionally, of all disease and non-battle injury patients with a musculoskeletal diagnosis, 74.7% had an extremity complaint, 44.1% had a lower extremity diagnosis, and 23.2% had foot or ankle pathology. Of all 1236 patients evacuated during this period, 39.5% had extremity pathology, 25.8% had lower extremity pathology, and 12.4% had foot and ankle pathology in isolation or combined with other complaints. Extremity injuries, and specifically lower extremity injuries, continue to be the predominant wounding pattern found in surviving troops in modern warfare. Proper staffing and positioning of medical specialties involved in musculoskeletal trauma care is vital in ensuring proper casualty care in future conflicts.

Disease management for the diabetic foot: Effectiveness of a diabetic foot prevention program to reduce amputations and hospitalizations

Objective: To demonstrate the effectiveness of a diabetic foot disease management program in a managed care organization. Methods: We implemented a lower extremity disease management program consisting of screening and treatment protocols for diabetic members in a managed care organization. Screening consisted of evaluation of neuropathy, peripheral vascular disease, deformities, foot pressures, and history of lower extremity pathology. We stratified patients into low and high-risk groups, and implemented preventive or acute care protocols. Utilization was tracked for 28 months and compared to 12 months of historic data prior to implementation of the disease management program. Results: After we implemented the disease management program, the incidence of amputations decreased 47.4% from 12.89 per 1000 diabetics per year to 6.18 ( p < 0.05). The number of foot-related hospital admissions decreased 37.8% from 22.86 per 1000 members per year to 14.23 (37.8%). The average inpatient length-of-stay (LOS) was reduced 21.7% from 4.75 to 3.72 days ( p < 0.05). In addition, there was a 69.8% reduction in the number of skilled nursing facility (SNF) admissions per 1000 members per year (Table 1) and a 38.2% reduction in the average SNF LOS from 8.72 to 6.52 days ( p < 0.05). Conclusion: A population-based screening and treatment program for the diabetic foot can dramatically reduce hospitalizations and clinical outcomes.

An Audit of Keller Arthroplasty and Metatarsophalangeal Joint Arthrodesis from National Data

Chronic interphalangeal ulcerations of the great toe are a frequent complication in neuropathic diabetic feet. While total contact casting is usually effective as a first-line treatment, some ulcers continue and present substantial management challenges. The objective of this study was to examine the National Hospital Discharge Survey in order to identify links between preexisting medical conditions and lower extremity pathology in patients undergoing a Keller arthroplasty. Those who received a Keller arthroplasty were more likely to have diabetes mellitus (odds ratio [OR] = 4.00, 95% confidence interval [CI]: 3.73-4.30, P = .0001), diabetic neuropathy (OR = 3.80, 95% CI: 3.48-4.15, P = .0001), coronary artery disease (OR = 1.78, 95% CI: 1.57-2.03), or peripheral vascular disease (PVD) (OR = 2.06, 95% CI: 1.49-2.84, P = .0001). Keller arthroplasty patients were less likely to have a foot abscess (OR = 0.44, 95% CI: 0.39-0.50, P = .0001) or hammer toe deformity (OR = 0.60, 95% CI: 0.57-0.63, P = .0001), but more likely to have a foot wound or ulcer (OR = 2.62, 95% CI = 2.44-2.82, P = .0001), bunions (OR = 4.52, 95% CI: 4.26-4.80, P = .0001), and osteomyelitis (OR = 2.65, 95% CI: 2.41-2.92, P = .0001). Hallux limitus or rigidus in a diabetic patient with neuropathy, peripheral vascular disease, and poor healing subjects this patient to a higher risk of ulceration, infection, and amputation. This study shows that this procedure is being performed in the diabetic population with attendant complications.

Peroneus longus stretch reflex amplitude increases after ankle brace application

Background: The use of external ankle support is widespread throughout sports medicine. However, the application of ankle bracing to a healthy ankle over a long period has been scrutinised because...

Test–Retest Reliability of Lower Extremity Functional Tests after a Closed Kinetic Chain Isokinetic Testing Bout

Context:Athletes are often examined for return to sports using a functional-testing algorithm. No research has determined whether a closed kinetic chain (CKC) isokinetic testing bout influences the reliability of functional tests.Objective:To determine whether a concentric CKC isokinetic test bout alters test–retest reliability of lower extremity functional testing.Design:Subjects participated in velocity-spectrum CKC isokinetic bouts on 2 days 1 week apart.Setting:Hospital-based clinic.Participants:28 normal subjects (mean age 26.7 years, height 27.2 cm, weight 75.8 kg).Analysis and Results:Means and SDs were determined. Intraclass correlation coefficients were used to calculate test–retest reliability and between days 1 and 2 ranged from .91 to .98.Conclusions:Even after a CKC isokinetic test bout, test–retest reliability of functional tests is very high. Future research should determine test–retest reliability of functional tests for patients with lower extremity pathology.

Fatigability and Variable-Frequency Train Stimulation of Human Skeletal Muscles

The quadriceps femoris (QF) and tibialis anterior (TA) muscles are often activated through the use of electrical stimulation by physical therapists. These 2 muscles are fundamentally different in regard to their fiber-type composition. Whether protocols developed using a given muscle can be applied to another muscle has seldom been questioned, even if they differ in fiber type. The purpose of this study was to test the hypothesis that torque augmentation during variable-frequency train (VFT) stimulation as compared with constant-frequency train (CFT) stimulation in the fatigued state would not differ between these muscles, even though the TA muscle has 50% relatively more slow fibers than the QF muscle relative to each muscle's overall composition. Ten recreationally active men with no history of lower-extremity pathology participated in the study (mean age=25 years, SD=4, range=19-31; mean height=179 cm, SD=5, range=170-188; mean body mass=80 kg, SD=15, range=63-111). The subjects' TA and QF muscles were stimulated with CFTs (six 200-microsecond square waves separated by 70 milliseconds) or VFTs (first interpulse interval=5 milliseconds) that evoked an isometric contraction. After potentiation, the torque-time integral and peak torque were not different for the VFT and CFT stimulation. Rise time was longer for the TA muscle than for the QF muscle and for CFT stimulation versus VFT stimulation (both approximately 40%). After 180 CFTs (50% duty cycle), peak torque decreased 56% overall, with no differences between muscles. Enhancement of the torque-time integral (25%) by VFT stimulation was not different between fatigued QF and TA muscles. Torque augmentation was due to the VFT stimulation evoking 27% greater peak torque and less slowing of rise time than the CFT stimulation (15% versus 30%). The results indicate that the QF muscle may not necessarily fatigue more than the TA muscle. The results suggest that VFTs augment the force of fatigued, human skeletal muscle irrespective of fiber type.

Diabetic limb salvage. A team approach at a teaching institution.

In this retrospective review, 19 diabetic patients with significant lower-extremity pathology were assessed to determine the success of limb salvage in cases of varying complexity. The patients were either scheduled or at risk for below-the-knee amputation before intervention. After the limb-salvage procedure, patients were followed for 4 months to 9 years. Eighteen patients went on to have successful procedures, avoiding below-the-knee amputation; one patient had an above-the-knee amputation. The results demonstrate the benefits of an aggressive team approach with limb salvage as a goal.

ANKLE BRACING DOES NOT AFFECT PERONEUS LONGUS RESPONSE FOLLOWING MUSCLE FATIGUE

The potential effects of ankle bracing on joint proprioception have not been well established. In our laboratory, we have recently showed a facilitation in peroneus longus (PL) stretch reflex amplitude after immediate application of a ankle brace. There is evidence that suggests that ankle bracing may enhance proprioception by increasing afferent input from various mechanoreceptors. It has been shown that diminished joint force output, and impaired motor control occurs following muscular fatigue. Therefore, the purpose of this research was to establish if ankle bracing can minimize the negative consequences of muscular fatigue by enhancing neuromuscular function of the peroneus longus (PL) during sudden foot inversion. Fifteen healthy collegiate volunteers (age = 21.7 ± 3.2 yrs, ht = 172.5 ± 11.1 cm, and mass = 73.7 ± 12.0 kg) free from lower extremity pathology 12 months prior to the study and not engaged in a strength training program served as subjects. All subjects had PL neuromuscular function {magnitude (% of max amplitude) and latency (ms)} assessed during sudden foot inversion during two ankle brace conditions (control & lace-up) before and after a standardized isokinetic muscular fatigue protocol. A repeated measures ANOVA revealed that PL stretch reflex magnitude was unaffected (P > 0.05) by brace condition (control = 86.8 ± 1.3; lace-up = 86.3 ± 1.1) and fatigue (pre = 85.6 ± 1.4; post = 87.6 ± 1.4). Similarly, PL stretch reflex latency remained unchanged (P > 0.05) by brace condition (control = 52.9 ± 2.9; lace-up = 50.2 ± 2.3) and fatigue (pre = 51.5 ± 2.4; post = 51.6 ± 2.2). It appears from these data that muscle fatigue does not influence the reactive response of the PL during sudden foot inversion. Additionally, application of a lace-up style ankle brace does not affect PL latency and magnitude following an inversion perturbation.

Changes in soleus motoneuron pool excitability after artificial knee joint effusion

Hopkins JT, Ingersoll CD, Edwards JE, Cordova ML. Changes in soleus motoneuron pool excitability after artificial knee joint effusion. Arch Phys Med Rehabil 2000;81:1199-1203. Objective: To compare changes in the magnitude of soleus motoneuron excitability before and over a 4-hour period following artificial knee effusion. Design: Before-after trial. Setting: All measurements were collected in the Sports Injury Research Laboratory, Indiana State University. Participants: Eleven healthy and neurologically sound volunteers (mean age ± SD, 24 ± 3yr; height, 173.2 ± 9.6cm; weight, 72.9 ± 8.7kg) with no history of lower-extremity surgery and no lower extremity pathology in the last year. Interventions: An area superolateral to the patella was cleaned and injected subcutaneously with 2mL of lidocaine for anesthetic purposes. With a second disposable syringe, 25mL of sterile saline was injected through the superolateral knee joint capsule into the joint space to mimic mechanical joint effusion. Main Outcome Measure: Hoffmann's reflex (H-reflex) was elicited by applying a percutaneous stimulus to the tibial nerve in the popliteal fossa. Seven to 12 stimuli were delivered at 20-second intervals with varying intensities to find the maximal H-reflex. The maximal H-reflex was measured five times at the same stimulus intensity with 20-second rest intervals. This measurement was recorded before injection and at 1-hour intervals following the injection for 4 hours. Results: An overall difference between groups was found. Measurements from hours 3 and 4 were significantly higher than the preinjection measurements (p ≤.05). Conclusions: The soleus motoneuron pool was not inhibited as expected. The soleus was facilitated beyond the preinjection level, showing that the quadriceps and soleus do not respond in the same way to artificial knee effusion. Because the quadriceps are normally inhibited during knee effusion, this facilitation could be the result of a compensatory reaction by the soleus in response to inhibited quadriceps. Further studies must be performed to determine the extent and duration of soleus motoneuron pool excitability in relation to quadriceps inhibition elicited by artificial knee effusion. © 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Plantar pressure assessment.

Measurements of plantar pressure provide an indication of foot and ankle functions during gait and other functional activities, because the foot and ankle provide both the necessary support and flexibility for weight bearing and weight shifting while performing these activities.1–3 Although plantar pressure data have been recognized as an important element in the assessment of clients with diabetes and peripheral neuropathy, information derived from plantar pressure data also can assist in determining and managing the impairments associated with various musculoskeletal, integumentary, and neurological disorders. The use of force platforms is the method most commonly used to assess the interaction of the foot and supporting surface. Although the force platform provides valuable information regarding both the vertical and shear components of the ground reaction force, it provides little information on how the planter surface of the foot is loaded with respect to the supporting surface. When evaluating patients, atypical amounts of loading or patterns of loading may be reflective of a systemic or localized lower-extremity pathology and may be indicators (risk factors) for or predictors of further pathology or worsening of the existing pathology.4 In addition, force platforms have very specific requirements for attachment to the supporting surface on which data collection will occur. Such is not the case with numerous commercially available systems for measuring plantar pressure (eg, Emed sensor platform, * Pedar insole system, * F-Scan system,† Musgrave footprint system‡). Thus, plantar pressure measurement systems offer the clinician a high degree of portability, permitting utilization among multiple clinic sites. Pressure (p) (also called “stress”) is defined as force (f) per unit area (a) (ie, p=f/a).5 Force , when measured using a force platform, is the net result of the 3 components of the ground reaction or resultant force acting on the foot. …

The effect of pregnancy on footprint parameters. A prospective investigation.

Pregnancy produces significant alterations in the posture of the pregnant woman; however, gait changes that occur during pregnancy have not been adequately evaluated in the literature. This prospective investigation of the footprints of 25 pregnant women from early pregnancy to just prior to parturition revealed a significant increase in the base of gait during walking. This change in gait function may be a compensatory mechanism to improve locomotor stability, and may have important implications for foot function and development of lower-extremity pathology in pregnant women.

COMPARISON OF EVENT TIMING AND GROUND REACTION FORCES AMONG FOUR METHODS OF RISING FROM SITING

163 Rising from a seated position is the most common gross movement pattern performed other than walking. Yet very little research has defined the components of forces and timing required for execution of the sit-to-stand(STS) movement. Using the hands on the chair's armrests may assist during the STS movement. If armrests are not available, the common recommendation is for the patient to put the hands on knees to assist in rising. The purpose of this study was to compare identifiable timing of events from three dimensional ground reaction forces (GRF) during four methods of STS. The conditions included: arms FREE; arms CROSSed; hands on KNEEs; and hands on ARMrests. Each of 100 normal subjects (50 men and 50 women) performed each STS movement on an AMTI forceplate. GRF's were recorded, analyzed (Ariel Systems) and normalized to percent of bodyweight in the X (lateral), Y (fore/aft) and Z (vertical) directions from initiation in the seated position to steady standing. Of the six distinct timing events in the Z direction the force for the ARM condition was significantly less than the other three methods at seat-off (11-13% less) and peak force (15-16% less) events. The time to peak force in the Z direction was significantly later for the ARM condition than the other three conditions. No differences for timing or forces were observed among methods in the Y direction. For the forces in the X direction no differences were revealed, but the KNEE condition was significantly earlier than the other three STS methods. No other significant differences were revealed among the FREE, CROSS, KNEE and ARM methods. This study established critical timing events in three dimensions which may be useful clinically for diagnosis and treatment of individuals with lower extremity pathologies. It was concluded rising from sitting using ARMrests resulted in the least vertical GRF. When armrests were not available there was no difference among the methods for the STS movement and the recommendation to use the hands on knees for the STS movement may not be valid.

Altered load history affects periprosthetic bone loss following cementless total hip arthroplasty

Dual energy x-ray absorptiometry was used to measure periprosthetic, distal femoral, and proximal tibial bone mass in the affected and contralateral limbs of eight patients 10 years after unilateral total hip arthroplasty with a cementless, porous-coated titanium alloy femoral stem. Gait analyses to assess the presence of asymmetries in loading of the lower extremities were also performed 10 years postoperatively. The patients had excellent clinical results and no other significant lower extremity pathology. On the basis of comparison of the affected and unaffected proximal femora, bone loss adjacent to the proximal medial aspect of the femoral stem was determined to be 34% (p < 0.001). However, the patients also had 16% less bone in the ipsilateral proximal tibia (p = 0.003) and 15% less bone in the ipsilateral femur 3 cm distal to the prosthesis (p = 0.007) compared with the contralateral limb. When normalized to the asymmetry in tibial bone mineral content, the estimated proximal medial periprosthetic bone loss was still statistically significant, but the magnitude was reduced from 34 to 17% (p = 0.009). The gait analyses indicated that several measures that influence the loads at the hip and knee joints were reduced in the involved limb compared with the contralateral limb. Furthermore, the bilateral difference in the vertical component of the external force acting on the proximal tibia was correlated with the bilateral difference in tibial bone mineral content (r = 0.80, p = 0.02). These data suggest that two mechanical factors, the local stress-shielding effect of the prosthesis and the global effect of decreased loading of the limb, can both make significant contributions to periprosthetic bone loss. It is apparent that the magnitude of the periprosthetic bone loss related to stress-shielding has been overestimated by as much as 50% in retrospective studies.

"Stand down for the homeless". Podiatric screening of a homeless population in Cleveland

Health care for the homeless is a major public health concern. With the rise in antibiotic-resistant tuberculosis, the increase of human immunodeficiency virus (HIV) diseases, and other health risks, the medical community has begun to recognize the urgency of taking a proactive role in providing care for this population. Lower extremity pathology can result in limb-threatening and, in some cases, life-threatening sequelae for homeless populations. This patient group has limited access to regular hygiene, appropriate shoes, and podiatric medical care. Participation in the "Stand Down for the Homeless" projects provided an opportunity to evaluate the podiatric needs of a homeless population and to project a response to those needs. The authors define and compare this homeless population with the national homeless population, compare the podiatric needs of this homeless populations versus the general population, and respond to those needs.