The authors acknowledge the funding of the Breeding Program of Shanghai Tenth People&#39;s Hospital (YNCR2C022).

This study was conducted at the Sports Medicine and Rehabilitation Centre, Shanghai University of Sport, and has been approved by the ethics committee of the Shanghai University of Sport (No. 102772020RT001). Before the test, the participants were given details about the experimental purpose and procedures; all participants signed the informed consent.
1. Participant selection
<ol>
	<li>Include participants who (1) are aged over 60 years old; (2) can maintain standing position alone; (3) can walk independently, without help from others, prosthesis, or mobility aids; (4) can display normal cognitive function and can understand the procedures and instructions of the test. Exclude participants who (1) were diagnosed with severe cardiopulmonary disease; (2) diagnosed with motor neuron disorders, such as Alzheimer&#39;s disease and Parkinson&#39;s disease; and (3) had a history of lower limb trauma in the past year were excluded. 
	NOTE: To evaluate the function of the foot core system, 42 elderly participants and 42 young participants whose demographic data matched with the old group (control group) were recruited for this study. The sample size was calculated for t-test with setting of &#945; = 0.05, power (1 &#8722; &#946;) = 0.95, and effect size = 0.8. The result shows that 42 participants in each group should be included in this study.</li>
</ol>
2. Active subsystem
NOTE: The morphology and strength tests of intrinsic and extrinsic foot muscles are used to evaluate the active subsystem.
<ol>
	<li>Muscle morphology
	<ol>
		<li>Turn on the musculoskeletal ultrasound system, and then click on the Freeze button. Plug the probe connector into the connection port on the rear side of the host and lock the Probe Lock button. Click on the iStation button, and then click on New Patient. Input the ID, name, gender, and date of birth of each participant. 
		NOTE: The probe cable should be arranged properly and placed in a location where it will not be easily trampled to ensure that the cable is not entangled with the other objects. Place the probe in a safe location to avoid collision and damage.</li>
		<li>Abductor hallucis (AbH): Apply the ultrasound coupling gel at the middle of the scanning line of tuberosity and navicular tuberosity. Place the probe at the medial calcaneal tuberosity toward the navicular tuberosity. Move the probe sightly to capture the thickest part of the AbH, and then click on the Save button to save the still image.
		<ol>
			<li>Then, rotate the probe 90&#176; to obtain the cross-sectional image of the AbH and save the image. 
			NOTE: Maintain good contact between the probe and the skin without applying excessive pressure in muscle morphology measurements.</li>
		</ol>
		</li>
		<li>Flexor digitorum brevis (FDB): Align the probe longitudinally on the line from the medial tubercle of the calcaneus to the third toe and scan the muscle to measure the thickness. Rotate the probe 90&#176; to obtain the cross-sectional image.</li>
		<li>Quadratus plantae (QP): Align the probe longitudinally along the muscle fibers at the talocalcaneonavicular joint. Move the probe sightly to locate the thickest part of QP. Capture three images for thickness measurement. Rotate the probe 90&#176; to obtain cross-sectional images. 
		NOTE: QP lies deep in the FDB.</li>
		<li>Flexor hallucis brevis (FHB): Mark the first metatarsal, apply the ultrasound coupling gel, and then place the probe longitudinally along the shaft. Move the probe sightly to capture the thickest part of the FHB, and then rotate the probe 90&#176; to obtain the cross-sectional image.</li>
		<li>Peroneus longus and brevis (PER): Instruct the participants to lie in the supine position. Mark the fibular head and the inferior border of the lateral malleolus, and mark 50% of the line connecting the two points. Apply the coupling gel and place the probe to capture the thickness. To obtain the cross-sectional image, rotate the probe 90&#176; at the point where the thickness measurement was taken.</li>
		<li>Tibialis anterior (TA): Apply the coupling gel in front of the calf over 20% of the distance between the fibular head and the inferior border of the lateral malleolus. Place the probe longitudinally along the TA to obtain a thickness measurement. 
		NOTE: Due to the scanning range of the probe, the CSA of the TA cannot be captured completely.</li>
		<li>Image measurement: Look for the previously captured images on the right side of the screen. Use the trackball to move the cursor, select one image, and click on the Set button. Then, click on the Measure button. The measurement items appear on the left side of the screen.
		<ol>
			<li>Thickness: Use the trackball to move the cursor, select the distance measurement, and click on the Set button. Mark the two points of the thickest part of the muscle in the image (Figure 1 and&#160;Figure 2). Record the distance for the thickness.</li>
			<li>Cross-sectional area (CSA): Use the trackball to move the cursor to trace the periphery of the muscle in the image. After tracing the cross-section of the entire muscle, click on the Set button (Figure 1 and Figure 2). Record the area for the CSA.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Muscle strength
	<ol>
		<li>Insert dynamometer Bluetooth stick into the USB interface of the computer. Open the dynamometer and FET Data Collection Software and click on the Start Gauge button to wait for automatic pairing.</li>
		<li>Toe flexion strength test (FT1)
		<ol>
			<li>Instruct the participant to sit in a chair with 90&#176; flexion of the knee and ankle joint. Fix the dynamometer to the front side of the wooden frame. Connect the great toe to the dynamometer by carabiner (Figure 3B). 
			NOTE: Adjust the appropriate bars to avoid pain during the test.</li>
			<li>Interchange the panels behind the foot to ensure that the heel to the head of the first metatarsal is supported while still allowing for unimpaired toe flexion. Adjust the carabiner so that the toe produces a steady baseline force, and then click on the Reset button to zero out the dynamometer.</li>
			<li>Click on the Start Gauge button in the software. Instruct the participant to remain stable until instructed to flex the big toe, pull as hard as possible for 3 s, and then relax the grip. Click on the Stop Gauge button, and save the data collected.</li>
		</ol>
		</li>
		<li>Toe flexion strength test (FT2-3 and FT2-5)
		<ol>
			<li>Use the T-shaped metal bars to attach to the dynamometer. Instruct the participant to flex the 2nd-3rd toes or 2nd-5th toes. Perform a similar test procedure as the FT1 test (Figure 3C,D).</li>
		</ol>
		</li>
		<li>Doming test
		<ol>
			<li>Place the dynamometer against the scaphoid tubercle. Instruct the participant to slide the forefoot toward the heel or raise the arch as much as possible without lifting or curling the toes, which would result in &#34;shortening&#34; of the foot and a raised medial longitudinal arch (Figure 3A).</li>
			<li>Then, ask the participant to do maximum voluntary contraction for 3 s. Perform data collection like previous toe flexion tests (steps 2.2.2 and 2.2.3). 
			&#8203;NOTE: Record three successful trials for the data process and provide sufficient rest time between trials to avoid fatigue.</li>
		</ol>
		</li>
		<li>Open the program software processing window and import the CSV files of the original strength data.
		<ol>
			<li>Toe flexion force (FT1, FT2-3, FT2-5): Click on the Run button, select the Automatic Calculation option in the calculation list, and then click on the Calculation button. The software will actively calculate the peak strength of the toe grip (Figure 4).</li>
			<li>Doming force data: Import the original data into the software and click on the Run button. Select the Manual Calculation option in the calculation list. Then, drag the movable 0.5 s window manually, where the force curve is in the shape of a plateau, and the software will automatically calculate the average force in the window (Figure 5).</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63479/63479fig01.jpg" /> 
Figure 1: Representative ultrasound images of three intrinsic muscles. (A) Thickness Image of the abductor hallucis; (B) cross-sectional area of the abductor hallucis; (C) thickness image of the flexor digitorum brevis; (D) cross-sectional area of the flexor digitorum brevis; (E) thickness image of the quadratus plantae; and (F) cross-sectional area of the quadratus plantae. <a href="https://www.jove.com/files/ftp_upload/63479/63479fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63479/63479fig02.jpg" /> 
Figure 2: Representative ultrasound images of three extrinsic muscles. (A) Thickness image of the flexor hallucis brevis; (B) cross-sectional area of the flexor hallucis brevis; (C) thickness image of peroneus longus and brevis muscles; (D) cross-sectional area of peroneus longus and brevis muscles; and (E) thickness image of the tibialis anterior. <a href="https://www.jove.com/files/ftp_upload/63479/63479fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63479/63479fig03.jpg" /> 
Figure 3: Foot muscle strength test. (A) Doming test; (B) toe flexion strength test (FT1); (C) toe flexion strength test (FT2-3); (D) toe flexion strength test (FT2-5). <a href="https://www.jove.com/files/ftp_upload/63479/63479fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/63479/63479fig04.jpg" /> 
Figure 4: Representative toe flexion strength plot. The peak force of toe flexion is calculated as the average value of six data points around the selected peak point. In the custom software, it is programmed that 10 points, including peak force remain relatively stable to avoid false peaks, which means that the remaining nine points do not exceed &#177;0.5 of the peak value. <a href="https://www.jove.com/files/ftp_upload/63479/63479fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/63479/63479fig05.jpg" /> 
Figure 5: Representative doming strength plot. The force of maximum voluntary contraction is calculated for the doming strength. A movable 0.5 s window is present to determine where the force curve is in the shape of a plateau, which could be dragged manually. The strength of doming is programmed to calculate the average value of the selection window (0.5 ms). <a href="https://www.jove.com/files/ftp_upload/63479/63479fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
3. Passive subsystem
NOTE: The ND and foot posture index-6 (FPI-6) tests were applied to evaluate the foot structure (passive subsystem).
<ol>
	<li>Navicular drop (ND) test
	<ol>
		<li>Assemble the height vernier caliper with the base, fixture block, and scribing claw. To specify the navicular tuberosity, extend the scribing claw through a stick. Place the height vernier caliper on the horizontal platform. 
		NOTE: The ND test is performed on the same horizontal platform.</li>
		<li>Instruct the participants to sit on a height-adjustable chair and turn sideways to allow visualization of the medial longitudinal arch. Palpate the navicular tuberosity and mark its location. Instruct the participants to sit in a position where the knee, hip, and ankle joints make a 90&#176; angle.</li>
		<li>Palpate the medial and lateral aspects of the participant&#39;s talus head. Supinate and pronate the subtalar joint until the medial and lateral sides of the talus are equally positioned.</li>
		<li>Align the head of the scribing claw with the marked navicular tuberosity. Read and record the height at this non-weight-bearing position (height 1).</li>
		<li>Instruct the participants to stand and keep the normal, bilateral, weight-bearing stance. Consistently, record the height (height 2).</li>
		<li>Define the vertical movement of the navicular tuberosity (i.e., height 1-height 2) in the sagittal plane as ND. 
		NOTE: In the process of the ND test, the participants must keep straight and look straight ahead.</li>
	</ol>
	</li>
	<li>Foot posture index-6 (FPI-6)
	<ol>
		<li>Perform the FPI-6 test on the horizontal platform as in the ND test (step 3.1.1).</li>
		<li>Instruct the participants to take several steps, marching on the spot, and then stand in their relaxed stance position with double limb support. Inform them to stand still for approximately 2 min during the assessment.</li>
		<li>Palpate the talar head and rate its position on the lateral and medial sides.</li>
		<li>Palpate the lateral malleolar and score the supra- and infra-lateral malleolar curvature.</li>
		<li>Observe the calcaneal frontal plane position and score the angle between the posterior aspect of the calcaneus and the long axis of the foot.</li>
		<li>Palate the talonavicular joint (TNJ) and score the bulge or concave in this area.</li>
		<li>Palate and observe the curve of the medial longitudinal arch and score its height and congruence.</li>
		<li>Observe the forefoot directly behind and in line with the long axis of the heel and score the relative position of the forefoot on the rearfoot (abduction/adduction). 
		&#8203;NOTE: In this test, each item is scored as -2, -1, 0, 1, and 2 (see Supplementary File 1).</li>
	</ol>
	</li>
</ol>
4. Neural subsystem
NOTE: In the assessment of the neural subsystem, the plantar light touch threshold, and a two-point discriminator (TPD) were applied to evaluate the plantar sensitivity.
<ol>
	<li>Plantar light touch threshold
	<ol>
		<li>Prepare Semmes-Weinstein monofilament (SWM) kit, consisting of 20 pieces. Each SWM kit has an index number ranging from 1.65 to 6.65 (1.65, 2.36, 2.44, 2.83, 3.22, 3.61, 3.84, 4.08, 4.17, 4.31, 4.56, 4.74, 4.93, 5.07, 5.18, 5.46, 5.88, 6.10, 6.45, and 6.65), which is related to a calibrated breaking force (i.e., index 1.65 is the equivalent of 0.008 g of force). 
		NOTE: The higher the index value, the stiffer and harder it is to bend.</li>
		<li>Mark the test regions in the plantar sole, including the first toe (T1), first metatarsal head (MT1), third metatarsal head (MT3), fifth metatarsal head (MT5), midfoot (M), and heel (H).</li>
		<li>Apply 4.74 SWM to the participants&#39; thenar eminences to feel the stimulus, which they will receive on the plantar sole in the formal test. Instruct participants to say &#34;yes&#34; and inform the examiner of the accurate site clearly and loudly every time the participants perceive the sensory stimulus of SWM at any tested sites. 
		NOTE: Every marked region can be replaced by one specific number in the convenience of memory.</li>
		<li>Place each participant in the prone position on a standard treatment table facing away from the examiner with the foot hanging on the edge of the table. Instruct them to close their eyes and wear headphones to avoid the assistance of vision and minimize distraction, respectively.</li>
		<li>Apply SWM perpendicularly to the skin at the target region. Pressure is appropriate until the nylon SWM is bent to form a &#34;C&#34; shape. Then, hold it for 1 s before removal. 4.74 SWM is first applied over the marked region, and a 4-2-1 stepping algorithm is utilized to standardize the assessment21. Test six plantar regions at random. 
		NOTE: Provide a few seconds for rest in the interval of trails in case of sensory disturbance between marked regions. The last detected SWM is regarded as the threshold for that site.</li>
	</ol>
	</li>
	<li>Two-point discriminator (TPD)
	<ol>
		<li>Prepare the two-point discriminator device. The adjustable device has different distances, ranging from 1 mm to 15 mm. 
		NOTE: One side of the dial ranges from 1 mm to 8 mm, and revolving the dial to the other side ranges from 9 mm to 15 mm.</li>
		<li>Mark the six test regions in the plantar sole, which are the same as those in the case of the plantar light touch threshold test (step 4.1.2).</li>
		<li>To make participants familiar with the testing process, apply the two-point discriminator in the participants&#39; tip of the middle finger. Inform them to say &#34;one&#34; if they perceived one point or &#34;two&#34; if they perceived two points. 
		NOTE: The test position is the same as that in the plantar light touch threshold test. The participants should keep their eyes closed.</li>
		<li>Start the test from the greatest distance (8 mm), and then decrease the width distance by 5 mm until the participants report one point. Move the device in 1 mm increments applying randomization of one or two points until the participants can consistently identify two points at a test width. 
		NOTE: Three times of correctly identifying two-point touch out of five touches is defined as positive. The last two-point value is recorded as the TPD threshold value.</li>
	</ol>
	</li>
</ol>

The authors have no conflicts of interest.

The presented protocol is used to measure the characteristics of the foot in the elderly, which provides a comprehensive assessment to investigate foot core stability, including the passive, active, and neural subsystems. This new paradigm illuminates the foot function that interacts to stabilize the foot and sustain sensorimotor function in daily activities33. In previous studies, the researchers paid more attention to exploring foot deformity; toe flexion strength; diminished plantar sensory; an...

The human foot is a highly complex structure, consisting of bones, muscles, and tendons that attach to the foot. As a segment of the lower extremity, the foot constantly provides direct source contact with the supporting surface and hence contributes to weight-bearing tasks1. Based on the complex biomechanical interplay between muscles and passive structures, the foot contributes to shock absorption, adjusts for irregular surfaces, and generates momentum. Evidence shows that the foot contributes meaningfully to postural stability, walking, and running2,3,4.
According to a new paradigm proposed by McKeon5 in 2015, the foot core is rooted in the functional interdependence of the passive, active, and neural subsystems, which combine into the foot core system controlling foot motion and stability. In this paradigm, the foot bony anatomy forms the functional half dome, which includes the longitudinal arches and transverse metatarsal arches and flexibly adapts to load changes6. This half dome and passive structures, including the ligaments and joint capsules, constitute the passive subsystem. Additionally, the active subsystem consists of foot intrinsic muscles, extrinsic muscles, and tendons. The intrinsic muscles act as local stabilizers responsible for supporting the foot arches, load dependence, and modulation7,8, while the extrinsic muscles generate foot motion as global movers. For the neural subsystem, several kinds of sensory receptors (e.g., capsuloligamentous and cutaneous receptors) in the plantar fascia, ligaments, joint capsules, muscles, and tendons contribute to foot dome deformation, gait, and balance9,10.
Several researchers have speculated that the foot contributes to daily activities in two main ways. One is by mechanical support via the functional arch and the modulation among lower limb muscles. The other is the input of plantar sensory information about the position11. Based on the foot core system, deficits in this system, including foot posture, the strength of intrinsic and extrinsic foot muscles, and sensation sensibility, may predispose to the weakness of mobility and balance9,11,12,13.
However, with advancing age, alterations to the aspect, biomechanics, structure, and function of the foot commonly occur, including foot or toe deformities, weakness of foot or toe strength, plantar pressure distribution, and reduced plantar tactile sensitivity14,15,16,17. The presence of toe deformity and the severity of hallux valgus are associated with mobility and fall risk in the elderly11,18. Moreover, the strength of toe flexor muscles, which used to be overlooked, contributes to balance in elderly people19. Meanwhile, the elderly are also at higher risks to have foot conditions associated with pathologies such as diabetes, peripheral arterial disease, neuropathy, and osteoarthritis20,21.
The assessment, examination, and health care of the foot, especially in the elderly, have attracted increasing attention14,21. However, there is a limited study to explore the comprehensive evaluation for the function of the foot core system. Numerous studies aimed to explore foot pathological problems in the elderly, such as pain and nail, skin, bone/joint, and neurovascular disorders21,22,23. The role of the foot in mechanical support and sensory input during daily activities and as a functional core system needs to be recognized and evaluated, which was ignored in previous studies. Especially, the foot active components, including the intrinsic and extrinsic muscles, works as the local stabilizers and global movers and contribute to the foot stability and behavior in static posture and dynamic movement5.
The toe flexion strength is singularly reported to represent foot muscle strength, and it&#39;s also utilized to explore the relationship between foot function and other health situations, such as balance, and mobility24,25,26. Inherently, the foot muscle strength is limited to distinguishing the action of intrinsic and extrinsic muscles. Moreover, several tests, including the paper grip test and an intrinsic positive test, were criticized as non-quantitative tests that have poor reliability and validity7,27. Recently, a new evaluation of foot doming strength was reported to quantify the intrinsic foot muscle strength and it has been shown to have a good validity28. By measuring the doming (short-foot movement) strength, it contributes to directly quantifying the function of intrinsic muscle.
Therefore, a protocol is proposed here aiming to explore the characteristics of the foot in the elderly based on the foot core system, especially the function of the active subsystem. This protocol provides a comprehensive assessment to investigate foot core stability, including the passive, active, and neural subsystem, in the elderly. Moreover, alterations in foot core function have been reported in several health situations, such as plantar fasciitis, flat foot, and diabetes24,29,30. In the future studies, it might help to evaluate the foot function among different populations in a multidimensional measurement.

<table><tbody><tr><td>Diagnostic Ultrasound System</td><td>Mindray</td><td></td><td>It is used in clinical ultrasonic diagnostic examination.</td></tr><tr><td>ergoFet dynamometer</td><td>ergoFet</td><td></td><td>It is an accurate, portable, push/pull force gauge, which is designed to be a stand-alone gauge for capturing individual force measurements under any&lt;br/&gt; job condition.</td></tr><tr><td>Height vernier caliper</td><td></td><td></td><td>It is an accurate measure tool for height.</td></tr><tr><td>LabVIEW</td><td></td><td></td><td>It is a customed program software for strength analysis.</td></tr><tr><td>Semmes-Weinstein monofilaments</td><td>Baseline</td><td></td><td>It consists of 20 pieces, and each SWM haves an index number ranging from 1.65 to 6.65, that is related with a calibrated breaking force.</td></tr><tr><td>Two-Point Discriminator</td><td>Touch Test</td><td></td><td>It is a set of two aluminum discs, each containing a series of prongs spaced between 1 to 15 mm apart.</td></tr></tbody></table>

evaluating the function of the foot core system in the elderly

As a complex structure to link the body and the ground, the foot contributes to postural control in human static and dynamic activities. The foot core is rooted in the functional interdependence of the passive, active, and neural subsystems, which combine into the foot core system controlling foot motion and stability. The foot arch (passive subsystem), responsible for load, is considered the functional core of the foot, and its stability is necessary for normal foot functions. The functional abnormalities of the foot have been widely reported in the elderly, such as weakness of toe flexor muscles, abnormal foot postures, and decreased plantar sensory sensitivity. In this paper, a comprehensive approach is introduced for evaluating the foot function based on foot core subsystems. The strength and morphology of the foot intrinsic and extrinsic muscles were used to evaluate the foot muscle (active subsystem) function. The doming strength test was applied to determine the function of foot intrinsic muscles, while the toe flexion strength test focused more on the function of extrinsic muscles. The navicular drop test and foot posture index were applied to evaluate foot arch (passive subsystem) function. For the neural subsystem, the plantar light touch threshold test and two-point discrimination test were used to assess plantar tactile sensitivity at nine regions of the foot. This study provides new insights into the foot core function in the elderly and other populations.

In this study, 84 participants were included for measurement. The young&#160;group included 42 university students with an average age of 22.4 &#177; 2.9 years and height of 1.60 &#177; 0.05 m. The elderly group included 42 community-dwelling elderly with an average age of 68.9 &#177; 3.3 years and height of 1.59 &#177; 0.05 m.
Representative active subsystem results 
The morphology and strength of foot muscles are used to determine the function of the active subsystem. M...

Watch this Scientific Journal Video about Evaluating the Function of the Foot Core System in the Elderly at JoVE.com

Evaluating the Function of the Foot Core System in the Elderly

The functional core stability of the foot contributes to the human static posture and dynamic activities. This paper proposes a comprehensive evaluation for the function of the foot core system, which combines three subsystems. It may provide increased awareness and multifaceted protocol to explore the foot function among different populations.

As a complex structure to link the body and the ground, the foot contributes to postural control in human static and dynamic activities. The foot core is ...

evaluating-the-function-of-the-foot-core-system-in-the-elderly

Research

JoVE Journal

Neuroscience

2.6K Views.  Shanghai University of Sport. Het protocol stelt een uitgebreide evaluatie voor van de functie van het voetkernsysteem, en het kan zorgen voor een groter bewustzijn om de voetfunctie bij verschillende populaties te onderzoeken. Deze studie was gericht op het evalueren van de voetfunctie vanuit het perspectief van drie kernsubsystemen van een menselijke voet, met bijzondere aandacht voor actieve componenten. Het protocol kan nieuwe inzichten opleveren in evaluatie- en behandelingseffecten voor de voet- en enkeldisfuncties,...

Video: Evaluating the Function of the Foot Core System in the Elderly

Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 &#177; 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters.
With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p &#60;0.05). Also, with motion capture, larger single support time was found WP (p &#60;0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p &#60;0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p &#60;0.05). No changes were found for posture.
NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

The aim was to substantiate optimal use of data collection techniques for Nordic walking gait and posture analysis. Three-dimensional motion capture should be used during short duration analysis (i.e. single gait cycle), while accelerometry should be employed for longer duration analysis (i.e. repeated cycles) like a 6 Minute Walk Test.

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques ...

Behavior

Oscillation and Reaction Board Techniques for Estimating Inertial Properties of a Below-knee Prosthesis

The purpose of this study was two-fold: 1) demonstrate a technique that can be used to directly estimate the inertial properties of a below-knee prosthesis, and 2) contrast the effects of the proposed technique and that of using intact limb inertial properties on joint kinetic estimates during walking in unilateral, transtibial amputees. An oscillation and reaction board system was validated and shown to be reliable when measuring inertial properties of known geometrical solids. When direct measurements of inertial properties of the prosthesis were used in inverse dynamics modeling of the lower extremity compared with inertial estimates based on an intact shank and foot, joint kinetics at the hip and knee were significantly lower during the swing phase of walking. Differences in joint kinetics during stance, however, were smaller than those observed during swing. Therefore, researchers focusing on the swing phase of walking should consider the impact of prosthesis inertia property estimates on study outcomes. For stance, either one of the two inertial models investigated in our study would likely lead to similar outcomes with an inverse dynamics assessment.

Body segmental inertial properties are required for inverse dynamics modeling. Using an oscillation and reaction board technique, inertial properties of below-knee prostheses were measured. Using direct measures of prosthesis inertia in the inverse dynamics model of the prosthetic leg resulted in lower magnitudes of resultant joint forces and moments.

The purpose of this study was two-fold: 1) demonstrate a technique that can be used to directly estimate the inertial properties of a below-knee ...

Bioengineering

Clinical-oriented Three-dimensional Gait Analysis Method for Evaluating Gait Disorder

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, the use of 3DGA in actual clinics remains uncommon. Possible reasons could include the time-consuming measurement process and difficulties in understanding measurement results, which are often presented using a large number of graphs. Here we present a clinician-friendly 3DGA method developed to facilitate the clinical use of 3DGA. This method consists of simplified preparation and measurement processes that can be performed in a short time period in clinical settings and intuitive results presentation to facilitate clinicians&#39; understanding of results. The quick, simplified measurement procedure is achieved by the use of minimum markers and measurement of patients on a treadmill. To facilitate clinician understanding, results are presented in figures based on the clinicians&#39; perspective. A Lissajous overview picture (LOP), which shows the trajectories of all markers from a holistic viewpoint, is used to facilitate intuitive understanding of gait patterns. Abnormal gait pattern indices, which are based on clinicians&#39; perspectives in gait evaluation and standardized using the data of healthy subjects, are used to evaluate the extent of typical abnormal gait patterns in stroke patients. A graph depicting the analysis of the toe clearance strategy, which depicts how patients rely on normal and compensatory strategies to achieve toe clearance, is also presented. These methods could facilitate implementation of 3DGA in clinical settings and further encourage development of measurement strategies from the clinician&#39;s point of view.

In this study, a clinician-friendly three-dimensional gait analysis method, which was designed to be performed in the rehabilitation clinic, is presented. The method consists of a simplified measurement method and intuitive figures to facilitate clinicians&#39; understanding of the results.

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, ...

Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual&#39;s use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual&#39;s postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed.
Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants.

Individuals with intermittent claudication exhibit poor balance compared to healthy controls. Computerized dynamic posturography is an objective method for measuring an individual's postural responses to balance disturbances. This provides an objective reflection of the person&#x2019;s ability to respond to situations under which sensory stimuli are altered and unexpected perturbations occur.

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic ...

Medicine

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

Exergaming in Older People Living with HIV Improves Balance, Mobility and Ameliorates Some Aspects of Frailty

Approximately 1.2 million people in the United States live with HIV infection. Medical advancements have increased the life expectancy and this cohort is aging. HIV-positive individuals have a high incidence of frailty (~20%) characterized by depression and sedentary behavior. Exercise would be healthy, but due to the frail status of many HIV-positive individuals, conventional exercise is too taxing. The aim of this study was to evaluate the effectiveness and acceptability of a novel game-based training program (exergame) in ameliorating some aspects of frailty in HIV-infected individuals. Ten older people living with HIV were enrolled in an exergame intervention. Patients performed balance exercises such as weight shifting, ankle reaching, and obstacle crossing. Real-time visual/audio lower-extremity joint motion feedback was provided using wearable sensors to assist feedback and encourage subjects to accurately execute each exercise task. Patients trained twice a week for 45 min for 6 weeks. Changes in balance, gait, psychosocial parameters and quality of life parameters were assessed at the beginning, midterm and at conclusion of the training program. Ten patients completed the study and their results analyzed. The mean age was 57.2 &#177; 9.2 years. The participants showed a significant reduction in center of mass sway (78.2%, p = .045) during the semi-tandem balance stance with eyes closed and showed a significant increase in gait speed during a dual task motor-cognitive assessment (9.3%, p = .048) with an increase in stride velocity of over 0.1 m/sec. A significant reduction in reported pain occurred (43.5%, p = .041). Preliminary results of this exergame intervention show promise in improving balance and mobility while requiring older people living with HIV to be more active. The exergame can be continued at home and may have long term as well as short-term benefits for ameliorating frailty associated with HIV infection.

Persons infected with HIV are often frail, depressed and live a sedentary lifestyle for which conventional exercise is too taxing. Here, we present an exercise protocol that ameliorates aspects of frailty in HIV-infected persons. An exergame integrating cognitive control was developed using biosensors that measured balance, weight-shifting and obstacle crossing.

Approximately 1.2 million people in the United States live with HIV infection. Medical advancements have increased the life expectancy and this cohort is ...

Evaluating Postural Control and Lower-extremity Muscle Activation in Individuals with Chronic Ankle Instability

Computerized dynamic posturography (CDP) is an objective technique for the evaluation of postural stability under static and dynamic conditions and perturbation. CDP is based on the inverted pendulum model that traces the interrelationship between the center of pressure and the center of gravity. CDP can be used to analyze the proportions of vision, proprioception, and vestibular sensation to maintain postural stability. The following characters define chronic ankle instability (CAI): persistent ankle pain, swelling, the feeling of &#8220;giving way,&#8221; and self-reported disability. Postural stability and fibular muscle activation level in individuals with CAI decreased due to lateral ankle ligament complex injuries. Few studies have used CDP to explore the postural stability of individuals with CAI. Studies that investigate postural stability and related muscle activation by using synchronized CDP with surface electromyography are lacking. This CDP protocol includes a sensory organization test (SOT), a motor control test (MCT), and an adaption test (ADT), as well as tests that measure unilateral stance (US) and limit of stability (LOS). The surface electromyography system is synchronized with CDP to collect data on lower limb muscle activation during measurement. This protocol presents a novel approach for evaluating the coordination of the visual, somatosensory, and vestibular systems and related muscle activation to maintain postural stability. Moreover, it provides new insights into the neuromuscular control of individuals with CAI when coping with real complex environments.

Individuals with chronic ankle instability (CAI) exhibit postural control deficiency and delayed muscle activation of lower extremities. Computerized dynamic posturography combined with surface electromyography provides insights into the coordination of the visual, somatosensory, and vestibular systems with muscle activation regulation to maintain postural stability in individuals with CAI.

Computerized dynamic posturography (CDP) is an objective technique for the evaluation of postural stability under static and dynamic conditions and ...

Use of a Foot-Induced Digitally Controlled Resistance Device for Functional Magnetic Resonance Imaging Evaluation in Patients with Foot Paresis

Neurological deficits from a stroke can result in long-term motor disabilities, including those that affect walking gait. However, extensive rehabilitation following stroke is typically time limited. Establishing predictive biomarkers to identify patients who may meaningfully benefit from additional physical therapy and demonstrate improvement is important to improve the patients&#39; quality of life. Detection of neuroplastic remodeling of the affected region and changes in the activity patterns excited while performing suitable motor tasks could have valuable implications for chronic stroke recovery. This protocol describes the use of a digitally controlled, magnetic resonance-compatible foot-induced robotic device (MR_COFID) to present a personalized foot-motor task involving trajectory following to stroke-affected subjects with gait impairment during functional magnetic resonance imaging (fMRI). In the task, foot flexion is performed against bi-directional resistive forces, which are tuned to the subject&#39;s strength in both the dorsiflexion and plantar flexion directions, while following a visual metronome. fMRI non-invasively uses endogenous deoxyhemoglobin as a contrast agent to detect blood oxygenation level-dependent (BOLD) changes between the active and resting periods during testing. Repeated periodic testing can detect therapy-related changes in excitation patterns during task performance. The use of this technique provides data to identify and measure biomarkers that may indicate the likelihood of an individual benefitting from rehabilitation beyond that which is currently provided to stroke patients.

Chronic stroke patients' insured rehabilitation is generally time limited. Imaging-based study of brain activity from walking-related motor tasks can lead to establishing biomarkers to measure improved outcomes and justify extending tailored therapy. A novel, magnetic resonance-compatible, variable-resistance foot motion device and a protocol for use during functional magnetic resonance imaging are presented.

Neurological deficits from a stroke can result in long-term motor disabilities, including those that affect walking gait. However, extensive ...

The 4 M&#8217;s Framework: Case History and Physical Examination of Older Adults

Source:&#160;Jennifer A. Ouellet and Jaideep Talwalkar; Yale School of Medicine
To meet the needs of older adults, all health professionals should be well acquainted with the history and physical examination considerations unique to this population. Physical examination plays an important role in the older patient to detect physiologic changes of aging, risk factors, and signs of pathology. While most of the general principles of the standard examination for adults apply to older patients, there are additional specific considerations. For example, focused examinations of cognitive and functional status are critical, as are assessments of hearing, vision, nutritional status, and the nervous system. This video will provide an overview of key aspects of the physical examination in older adults, including the use of standardized tools such as the 4 M&#39;s, the Timed&#160;Get Up and Go, and the Mini-Cog.

The 4 M&amp;#8217;s Framework: Case History and Physical Examination of Older Adults

Source:&#160;Jennifer A. Ouellet and Jaideep Talwalkar; Yale School of Medicine
To meet the needs of older adults, all health professionals should be well ...

Education

JoVE Science Education

Clinical Skills

Physical Examinations IV

Foot Exam

Source: <a href="https://www.jove.com/author/Robert+E._Sallis">Robert E. Sallis</a>, MD. Kaiser Permanente, Fontana, California, USA
The foot is a complex structure composed of numerous bones and articulations. It provides flexibility, is the essential contact point needed for ambulation, and is uniquely suited to absorb shock. Because the foot must support the weight of the entire body, it is prone to injury and pain. When examining the foot, it is important to remove shoes and socks on both sides, so that the entire foot can be inspected and compared. It is important to closely compare the injured or painful foot to the uninvolved side. The essential parts of the evaluation of the foot include inspection, palpation (which should include vascular assessment), testing of the range of motion (ROM) and strength, and the neurological evaluation.

Foot Exam: Range of Motion, Strength and Sensory Exam

Source: Robert E. Sallis, MD. Kaiser Permanente, Fontana, California, USA
The foot is a complex structure composed of numerous bones and articulations. It ...

Evaluating the Function of the Foot Core System in the Elderly

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