Ipsilateral Foot Research Articles

Low back pain and other musculoskeletal pain comorbidities in individuals with symptomatic osteoarthritis of the knee: Data from the osteoarthritis initiative

To examine the association of concurrent low back pain (LBP), and other musculoskeletal pain comorbidity, with knee pain severity in symptomatic knee osteoarthritis (OA). Individuals from the Progression Cohort of the Osteoarthritis Initiative (n=1,389, ages 45-79 years) with symptomatic tibiofemoral knee OA were studied. Participants identified pain in the low back, neck, shoulder, elbow, wrist, hand, hip, knee, ankle, or foot. The primary outcome was the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) applied to the more symptomatic knee. We examined WOMAC pain score in persons with and without LBP, before and after adjusting for other musculoskeletal symptoms. Of the participants, 57.4% reported LBP. The mean±SD WOMAC pain score (possible range 0-20) was 6.5±4.1 in participants with and 5.2±3.4 in participants without LBP (P<0.0001). In multivariate analyses, LBP was significantly associated with increased WOMAC knee pain score (β [SE]=1.00 [0.21], P<0.0001). However, pain in all other individual musculoskeletal locations demonstrated similar associations with knee pain score. In models including all pain locations simultaneously, only LBP (β [SE]=0.65 [0.21], P=0.002), ipsilateral elbow pain (β [SE]=0.98 [0.40], P=0.02), and ipsilateral foot pain (β [SE]=1.03 [0.45], P=0.02) were significantly associated with knee pain score. Having >1 pain location was associated with greater WOMAC knee pain; this relationship was strongest for individuals having 4 (β [SE]=1.83 [0.42], P<0.0001) or ≥5 pain locations (β [SE]=1.86 [0.36], P<0.0001). LBP, foot pain, and elbow pain are significantly associated with WOMAC knee pain score, as are a higher total number of pain locations. This may have implications for clinical trial planning.

Covering the below‐knee amputation stump with the pedicled dorsalis pedis flap from the ipsilateral foot: A case report

It is important to preserve the length, appropriate durable skin, and sensation of the stump when performing below-knee amputation to achieve functional ambulation with a prosthesis. There are many reports of reconstruction procedures using microvascular surgery to preserve the optimum length of the amputation stump for prosthesis; however, free tissue reconstruction is necessary to accompany with the donor site morbidity. In this report, we describe our experience with a below-knee amputation and stump covering using the pedicled dorsalis pedis flap from the no longer usable foot in the case of a severe osteomyelitis of a lower extremity after highly contaminated Gustilo type IIIB fracture. We achieved a well-healed amputated stump with enough length for a prosthesis and for protective sensation. The pedicled dorsalis pedis flap is easily elevated without microvascular anastomosis and is one useful option for the reconstruction of the below-knee amputated stump in the specific case.

The effect of cane use method on center of mass displacement during stair ascent

The aim of the study was to examine the effect of forward and lateral cane placement on displacement of whole body center of mass (COM) and spatial relationship between COM and the cane during stair ascent (SA) in healthy adults. The data were obtained using three-dimensional motion analysis while ascending stairs non-reciprocally with following methods: (1) dominant foot stepped up first, then the opposite foot without a cane (NC); (2) forward placement of a quadricane followed by the ipsilateral foot, then contralateral foot (FCI); (3) forward cane placement followed by the contralateral foot, then ipsilateral foot (FCC); (4) ipsilateral foot stepping up first, followed by the contralateral foot, then the cane (LCI); (5) contralateral foot stepping up, followed by the ipsilateral foot, then the cane (LCC). The results indicated that the cane placement had significant effect on the medial–lateral (ML) COM displacement and the kinematics of the trunk. Lateral cane placement requires greater trunk extension and side-flexion. The major differences between ipsilateral and contralateral cane use are the motions at frontal and transverse planes in which the COM displacement in ML direction is larger in ipsilateral cane use. The COM displacement in ML direction is larger in ipsilateral use of cane (LCI and FCI). The results of this study may help clinicians better understand the possible nature of balance control in patients who ascend stairs with a cane, and suggest that the method of cane placement should be taken into consideration by clinicians when teaching the cane user to ascend stairs.

Kinematics in the Terminal Swing Phase of Unilateral Transfemoral Amputees: Microprocessor-Controlled Versus Swing-Phase Control Prosthetic Knees

Mâaref K, Martinet N, Grumillier C, Ghannouchi S, André JM, Paysant J. Kinematics in the terminal swing phase of unilateral transfemoral amputees: microprocessor-controlled versus swing-phase control prosthetic knees. Objectives To analyze the spatiotemporal parameters in the terminal swing phase of the prosthetic limb in unilateral transfemoral amputees (TFAs) compared with a group of asymptomatic subjects, and to identify a latency period (LP) in the TFA between the full extension of the prosthetic knee and the initial ground contact of the ipsilateral foot. To study the correlation between the LP and the duration of the swing phase. To evaluate the influence of the type of knee, the time since amputation, and the amputation level on the latency period. Design Three-dimensional gait analysis with an optoelectronic device. Setting Gait analysis laboratory of a re-education and functional rehabilitation service. Participants TFA (n=29) and able-bodied (n=15) subjects. Interventions Not applicable. Main Outcome Measures Spatiotemporal and kinematics gait parameters. Results The swing phase and the LP of the prosthetic limb, associated with a consequently longer single-limb stance phase in the intact limb, were significantly longer than those measured in the intact limbs of these subjects, as well as those measured on both lower limbs of the able-bodied subjects ( P<.05). There is a positive correlation ( P<.05; r 2=.58 between the LP and the swing phase on the TFA's prosthetic side. The LP measured in the prosthetic limb of TFA with a swing-phase control prosthetic knee is significantly greater than in those using the microprocessor-controlled prosthetic knee ( P<.05). Conclusions Of negligible duration in able-bodied subjects and in the intact limb of TFA, the LP is significantly greater in the prosthetic limb. It can explain the lengthened swing phase on the prosthetic side of those subjects. The use of a microprocessor-controlled prosthetic knee allows the LP to be reduced. This LP appears to be necessary to insure the stability of the prosthetic knee. We suggest calling this time “confidence time.”

The effect of substrate size on the locomotion and gait patterns of the kinkajou (Potos flavus)

Diagonal-sequence (DS) gaits, which are very rare among mammals, are common and well documented in primates and some arboreal marsupials. DS walking gaits have been reported in the kinkajou (Potos flavus), which shows ecological similarities with primates and arboreal opossums but lacks prehensile specializations of the hindfoot. Nevertheless, the actual frequency of DS gaits and the functional context in which these gaits occur in this highly arboreal mammal remain unknown. We examined the effect of substrate size on the locomotion and gait patterns of kinkajous by recording gaits in two individuals walking and running on poles of two different diameters and on a runway. Diagonality and limb duty factors were calculated for 534 gait cycles. Kinkajous relied mostly on DS gaits and trots during walking, and increased the diagonality of their gait patterns on thinner substrates. The proposed functional link between locomotion on thin branches and the presence of a grasping, primate-like hindfoot is not supported by these data. However, further analysis of kinkajou gait cycles showed that DS gaits may have advantages overlooked earlier. DS gaits, during walking, minimize the distance between two ipsilateral feet during short periods of unilateral bipedality, and per corollary maximize the distance between two contralateral feet during the much longer periods of diagonal bipedality. Such foot positioning during the gait cycle could be beneficial in walking on a relatively thin substrate and could explain why kinkajous adopt DS walking gaits, especially on thinner poles, despite lacking prehensile specializations of the hindfoot.

Effects of spinal cord stimulation with “standard clinical” and higher frequencies on peripheral blood flow in rats

Background: It is unclear whether spinal cord stimulation (SCS) at higher frequencies induces further increases in vasodilation and enhances clinical efficacy. Objectives: This study investigated effects of SCS at both a normal frequency (as used clinically) and two higher frequencies on peripheral vasodilation. Methods: A unipolar ball electrode was placed on the left dorsal column at the lumbar 2–3 spinal cord segments (L2–L3) in sodium pentobarbital anesthetized, paralyzed, and artificially ventilated rats. Cutaneous blood flow recordings from both ipsilateral (left) and contralateral (right) hind foot pads were measured with laser Doppler flow perfusion monitors. SCS at frequencies of 50, 200, or 500 Hz was applied at 30%, 60%, and 90% of motor threshold (MT) using standard square waves. Resiniferatoxin (RTX: an ultrapotent analog of capsaicin) and a calcitonin gene-related peptide (CGRP) receptor blocker (CGRP 8–37) was also used to elucidate mechanisms of SCS vasodilation at these higher frequencies. Results: SCS applied with the three frequencies produced similar MT ( n = 22). SCS at 500 Hz significantly increased cutaneous blood flow and decreased vascular resistance compared to changes induced by frequencies of 50 and 200 Hz ( P < 0.05, n = 8). RTX (2 μg/kg, i.v.) as well as CGRP 8–37 (2.37 mg/kg, i.v.) significantly reduced SCS-induced vasodilation at 500 Hz ( P < 0.05, n = 6) as compared to responses prior to administrations of these drugs. Conclusion: SCS at 500 Hz significantly increased SCS-induced vasodilation without influencing MT. Furthermore, effects of SCS at 500 Hz are mediated via activation of TRPV1-containing fibers and a release of CGRP.

Fractures of the Sustentaculum Tali: Injury Characteristics and Surgical Technique for Reduction

The sustentaculum tali of the calcaneus is a vital load-bearing structure. Isolated sustentacular fractures are rare and may have implications for future hindfoot function. This retrospective cohort study describes sustentacular fracture patterns and characteristics, associated foot injuries, and a method of surgical treatment via a medial approach to the calcaneus. During a 7-year period, 19 surgically-treated sustentacular fractures without calcaneal posterior facet involvement were identified from a prospectively-collected database at a single Level 1 regional trauma center. Of these, 15 underwent open reduction and internal fixation utilizing a medial approach to the calcaneus. Patient charts, plain radiographs, and CT scans were reviewed for injury characteristics/morphology and associated musculoskeletal injuries. Fourteen patients had associated ipsilateral foot/ankle injuries, and nine had other musculoskeletal injuries. Seven patients had intra-articular middle facet involvement, and seven had subtalar joint subluxation or dislocation. The medial approach to the calcaneus involves distal retraction of the neurovascular bundle and toe flexors. This allowed for an accurate indirect articular reduction using the extraarticular medial calcaneal cortex, as well as reduction of any associated subluxations. No complications were related to the surgical approach. Reduction was maintained through fracture healing. Fractures of the sustentaculum tali are rare injuries associated with high energy mechanisms, and associated ipsilateral foot injuries are common. Open reduction and internal fixation of these fractures was reliable and possible through a medial approach involving distal retraction of the digital flexors and neurovascular bundle, allowing for an anatomical extraarticular cortical reduction.

Shared neural resources between left and right interlimb coordination skills: The neural substrate of abstract motor representations

Functional magnetic resonance imaging was used to reveal the shared neural resources between movements performed with effectors of the left versus right body side. Prior to scanning, subjects extensively practiced a complex coordination pattern involving cyclical motions of the ipsilateral hand and foot according to a 90° out-of-phase coordination mode. Brain activity associated with this (nonpreferred) coordination pattern was contrasted with pre-existing isodirectional (preferred) coordination to extract the learning-related brain networks. To identify the principal candidates for effector-independent movement encoding, the conjunction of training-related activity for left and right limb coordination was determined. A dominantly left-lateralized parietal-to-(pre)motor activation network was identified, with activation in inferior and superior parietal cortex extending into intraparietal sulcus and activation in the premotor areas, including inferior frontal gyrus (pars opercularis). Similar areas were previously identified during observation of complex coordination skills by expert performers. These parietal-premotor areas are principal candidates for abstract (effector-independent) movement encoding, promoting motor equivalence, and they form the highest level in the action representation hierarchy.

Ipsilateral coordination at preferred rate: Effects of age, body side and task complexity

Functional imaging studies have shown that elderly individuals activate widespread additional brain networks, compared to young subjects, when performing motor tasks. However, the parameters that effect this unique neural activation, including the spatial distribution of this activation across hemispheres, are still largely unknown. Here, we examined the effect of task complexity and body side on activation differences between older and younger adults while performing cyclical flexion–extension movements of the ipsilateral hand and foot. In particular, easy (isodirectional) and more difficult (non-isodirectional) coordination patterns were performed with either the left or right body side at a self-selected, comfortable rate. Even in the absence of imposed pacing the older group activated a larger brain network, suggestive of increased attentional deployment for monitoring the spatial relationships between the simultaneously moving segments and enhanced sensory processing and integration. Evidence of age-dependent underactivation was also found in contralateral M1, SMA and bilateral putamen, possibly reflecting a functional decline of the basal ganglia–mesial cortex pathway in the older group. An ANOVA model revealed significant main effects of task complexity and body side. However the interaction of these factors with age did not reach significance. Consequently, we conclude that under self-paced conditions, task complexity and body side did not have a modulatory effect on age-related brain activation.

Comparative study of systemic intravenous and regional intravenous administration of prophylactic antibiotic in lower extremity orthopaedic surgery

In this study, we describe a technique for the delivery of regional antibiotic prophylaxis in patients undergoing reconstructive surgery in the lower extremities and compare the tissue antibiotic concentrations achieved by this technique with those achieved by standard systemic intravenous prophylaxis. The efficacy of a regional route for antibiotic prophylaxis in lower extremity orthopaedic procedures was investigated in 20 patients and compared with the standard systemic intravenous method in 45 patients using a second generation cephalosporin (ceforanide). The antibiotic (2 g) was given intravenously as the standard systemic prophylaxis at different intervals (10, 20 min and 2 h) before tourniquet inflation. The same dose of antibiotic was injected intravenously into the ipsilateral foot after the inflation of tourniquet. Samples of bone, fat and muscle were collected during the operation and assayed for ceforanide by a microbiological method. None of the patients experienced local or systemic adverse following the regional administration of ceforanide, or infections during the postoperative and follow-up period. Peak tissue levels of the systemic antibiotic were observed when the antibiotic was given 20 min before tourniquet inflation. For all tissue samples, the antibiotic levels were significantly higher when the antibiotic was given regionally (P < 0.001). The results of this study suggest that the regional administration could be a useful route for prophylaxis during lower extremity orthopaedic procedures when they are carried out under tourniquet control.

Shoes influence lower limb muscle activity and may predispose the wearer to lateral ankle ligament injury

Lateral ankle ligaments are injured by hyperinversion of the foot. Foot position is controlled by the lower limb muscles. Awareness of foot position is impaired by wearing shoes. We aimed to determine the influence of wearing shoes upon muscle activity. Sixty-two healthy subjects underwent the same measurements, barefoot and with standardized shoes in a random order. Electromyography (EMG) was recorded from the peroneus longus muscle in response to sudden and unanticipated inversion of the ipsilateral foot. Following foot inversion, the EMG signal showed an initial peak muscle contraction followed by a sustained smaller contraction. Both changes were significantly greater in shoes compared to the barefoot condition for all tested degrees of inversion. Muscle contraction following sudden inversion of the foot was significantly greater when wearing shoes. This greater muscular contraction may be an intrinsic mechanism to oppose the increased moment created by the inverted foot/shoe condition, and hence, may counter balance the increased tendency to injure the lateral ankle ligaments created by wearing shoes.

A Randomized Comparison of a Modified Intertendinous and Classic Posterior Approach to Popliteal Sciatic Nerve Block

In this prospective randomized study, we compared a single-injection modified intertendinous (n = 55) with the classic posterior (n = 54) popliteal sciatic nerve block for patients undergoing ankle/foot surgery. Nerve stimulator-guided blocks were performed 7-8 cm (classic posterior) or 12-14 cm (modified intertendinous) above the popliteal crease. Levobupivacaine 0.625% with epinephrine 1:300,000 (Chirocaine(R), Purdue Pharma, Stamford, CT), was injected in 5 mL aliquots to a total volume of 0.4 mL/kg (range, 25-35 mL). The needle position was considered acceptable if an evoked motor response of plantar flexion, inversion, eversion or a dorsiflexion of the ipsilateral foot was elicited at <or=0.4 mA. Complete block was defined as pinprick anesthesia and motor paralysis of the foot within 60 min. The median distance from the popliteal crease to the modified intertendinous site was 14.0 cm (interquartile range, 13.5-15 cm) compared to 7.5 cm (interquartile range 7.0-8.0 cm) for the classic posterior site (P < 0.01). Complete block was achieved in 44 of 55 patients (81.5%) in the modified intertendinous compared to 39 of 54 patients (70.9%) in the classic posterior group (P = 0.26). Complete block frequency was greater with an evoked motor response of inversion 49 of 56 patients (87.5%) and plantar flexion 23 of 30 patients (76.7%) compared with dorsiflexion/eversion 11 of 23 patients (47.8%) (P = 0.001). The median (95% CI) time (min) to complete block with an evoked motor response of inversion was 10 (0-22 min) for the modified intertendinous compared to 30 (4-56 min) with the classic posterior approach (P = 0.04). Potential advantages of the modified intertendinous approach include more rapid onset of anesthesia with an evoked motor response of inversion compared to a classic posterior popliteal sciatic nerve block.

Withdrawal reflexes examined during human gait by ground reaction forces: site and gait phase dependency

The objective of this study was to investigate the modulation of the nociceptive withdrawal reflex during gait measured using Force Sensitive Resistors (FSR). Electrical stimulation was delivered to four locations on the sole of the foot at three different time points between heel-off and toe-off. Peak force changes were measured by FSRs attached to the big toe, distal to the first and fourth metatarsophalangeal joints, and the medial process of the calcaneus on both feet. Force changes were assessed in five gait sub-phases. The painful stimulation led to increased ipsilateral unloading (10 +/- 1 N) and contralateral loading (12 +/- 1 N), which were dependent on stimulation site and phase. In contrast, the hallux of the ipsilateral foot plantar flexed, thus facilitating the push-off. The highest degree of plantar flexion (23 +/- 10 N; range, 8-44 N) was seen in the second double support phase following the stimulation. Site and phase modulation of the reflex were detected in the force signals from all selected anatomical landmarks. In the kinematic responses, both site and phase modulation were observed. For stimulations near toe-off, withdrawal was primarily accomplished by ankle dorsiflexion, while the strategy for stimulations at heel-off was flexion of the knee and hip joints.

Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart

The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber hand illusion, we demonstrate that skin temperature of the real hand decreases when we take ownership of an artificial counterpart. The decrease in skin temperature is limb-specific: it does not occur in the unstimulated hand, nor in the ipsilateral foot. The effect is not evoked by tactile or visual input per se, nor by simultaneous tactile and visual input per se, nor by a shift in attention toward the experimental side or limb. In fact, taking ownership of an artificial hand slows tactile processing of information from the real hand, which is also observed in patients who demonstrate body disownership after stroke. These findings of psychologically induced limb-specific disruption of temperature regulation provide the first evidence that: taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top-down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in numerous states characterized by both.

Tasks of Attention Augment Rigidity in Mild Parkinson Disease

The purpose of this study was to determine whether tasks involving effortful attention would cause augmentation of rigidity in patients with mild Parkinson disease. In 17 subjects with mild Parkinson disease, rigidity in a single arm was assessed during various experimental conditions by a blinded movement disorders neurologist. Rigidity was scored separately at the wrist and the elbow using an ordinal scale. In three of the conditions, sustained attention was directed toward visual, auditory or movement-related stimuli. Two varieties of Froment maneuver served as positive controls: contralateral hand opening-closing or ipsilateral foot tapping. In addition, rigidity was assessed twice with subjects resting. The examiner was unaware of the sequence of experimental conditions and this was changed for each subject. Mean rigidity scores for the various experimental conditions were compared against the baseline state (an average of both trials with the patient resting) using a repeated measures ANOVA and post-hoc Tukey-Kramer multiple comparisons test. Rigidity was significantly increased from baseline with each of the attentional tasks (p < 0.01 to p < 0.001) and also with the two Froment maneuvers (p < 0.001). Rigidity augmentation with contralateral hand opening-closing was significantly greater than with any of the attentional tasks (p < 0.05 to p < 0.001). Tasks of effortful attention did appear to augment rigidity in patients with mild Parkinson disease. We speculate that the greater augmentation seen with the Froment maneuver could have an anatomic basis.

Gait and kinematics of the trunk and lower extremities in stair ascent using quadricane in healthy subjects

Different cane placement methods require different gait patterns and ranges of motion either at the trunk or lower extremities. The aim of this study was to examine the effect of cane placement on body biomechanics in stair ascent (SA) in 16 healthy adults (9 women, 7 men) aged 27.2 ± 3.2 years old. The height and weight of the women and men were 160.8 ± 5.4 cm and 54.1 ± 8.1 kg, and 170.8 ± 3.9 cm and 69.6 ± 5.6 kg, respectively. Three-dimensional motion data were collected in non-reciprocally SA associated with following methods: (1) dominant foot stepped up first, then the opposite foot without a cane (NC); (2) forward placement of a quadricane followed by the ipsilateral foot, then contralateral foot (FCI); (3) forward cane placement followed by the contralateral foot, then ipsilateral foot (FCC); (4) ipsilateral foot stepping up first, followed by the contralateral foot and the cane (LCI); (5) contralateral foot stepping up, followed by the ipsilateral foot and cane (LCC). LCI and LCC were considered as lateral cane placement. Temporal gait parameters, kinematics of the trunk and lower extremities were calculated. The results indicate that the cane placement had significant effect on the kinematics of the trunk and lower extremities. The main differences between forward and lateral cane placement were flexion and side flexion of the trunk, and flexion of the leading and opposite hip and knee. Hip rotation and abduction, and ankle plantar and dorsiflexion were different between contralateral and ipsilateral cane placements.

Validation of a sham for percutaneous tibial nerve stimulation (PTNS)

Percutaneous tibial nerve stimulation (PTNS) supposedly demonstrates 50-60% improvement in OAB symptoms with no sham-controlled trials reported. This study determined the efficacy of a sham for PTNS. Thirty healthy volunteers (15 women; 15 men) in this blinded pilot study were randomized into two equal groups: one group had PTNS on the right and sham on the left; the other group had PTNS on the left and sham on the right. A drape obscured their lower extremities. The sham utilized a placebo needle placed at the PTNS site along with a transcutaneous electrical nerve stimulator (TENS) pad on the ipsilateral foot. The unit was activated until stimulation was felt. PTNS was performed on the opposite leg, with the grounding pad mimicking the sham pad placement. PTNS stimulation was given until the subject felt stimulation in the foot. Subjects had 1 simultaneous 15 min testing of the PTNS vs. sham. Subjects then completed a questionnaire stating which leg they thought had the sham and PTNS (or "unknown"). The primary endpoint of the study was the ability to accurately identify the sham. In total, 10/30 (33%) of the shams were identified correctly. We would expect 50% to be identified by guessing, but only 33% were correctly identified. Females identified the sham correctly more often than males (40% vs. 27%). This procedure was validated as a feasible sham for PTNS. This is the first validation of a sham for PTNS that may be used in future placebo-controlled research.

Congenital unilateral bowing of tibia and fibula

Bowing of tibia refers to bending of diaphysis with apex of curve directed anterolaterally, anteromedially or posteromedially. Posteromedial bowing of tibia is a congenital condition often associated with calcaneovalgus deformity of ipsilateral foot. This condition undergoes spontaneous resolution to a major extent, often leaving only leg length inequality. The latter may result in abnormal gait and backache. We present a rare case of unilateral posteromedial bowing of tibia.

Sudden turn during walking is impaired in people with Parkinson’s disease

The present study compared kinematic strategies for making sudden directional changes during walking between patients with Parkinson's disease (PwPD) and age-matched controls. Ten PwPD and 10 healthy elderly were visually cued to walk straight or to turn either 30 degrees or 60 degrees to the left or right, at the mid-point of a 9-m walkway. Three-dimensional kinematic data recorded: (1) the onset time of body segments in response to the turning cue, and (2) step width at the first ipsilateral foot contact (IFC(1)) marking the beginning of turn, the subsequent contralateral foot contact (CFC), and the second ipsilateral foot contact (IFC(2)) marking the completion of turn. For both 30 degrees and 60 degrees turns, PwPD had later onset times for lateral foot displacement, and larger time lags between the onset of body CoM and the lateral foot translation than healthy subjects (P < 0.05). Furthermore, PwPD had a significantly narrower step width than healthy subjects (P < 0.05). Despite these differences, PwPD and control subjects scaled up turning speed and amplitude similarly for 30 degrees and 60 degrees turns. Our findings suggested that PwPD manifested specific difficulty in modifying their ongoing motor program to switch their locomotion from straight line to sideway direction, but their ability to scale movement speed and amplitude appeared to be preserved.

Results of cruciate retaining total knee arthroplasty

Purpose of review The aim of this article is to review recent publications regarding the results of posterior cruciate ligament retaining total knee arthroplasty, the most commonly implanted type of knee replacement used worldwide. Recent developments in understanding of the kinematics of these implants are discussed together with clinical follow-up studies. Recent findings The cruciate retaining total knee arthroplasty is a successful implant design and can be safely used in patients with rheumatoid arthristis. Infection, aseptic loosening or wear of the insert continue to be the main modes of failure of cruciate retaining total knee arthroplasty. All polyethylene and metal-backed tibias have similar outcome at 10 years. Presence of a ipsilateral planovalgus foot can increase the risk of failure of cruciate retaining total knee arthroplasty. Mobile bearing knees tend to have low-grade wear whereas high-grade wear is more common in the fixed bearing designs. High-flex designs might improve tibiofemoral contact biomechanics if high flexion is achievable, although their clinical advantages are still unproven. Summary Fixed bearing cruciate retaining total knee arthroplasty have a good track record. Advances are being made in the field of implant design although as yet no obvious clinical advantages have been proven.