Clinical assessment of walking and running gait

INTRODUCTION — Obtaining a history and performing a standard physical examination of a stationary patient in an examination room is often sufficient to develop a working differential diagnosis for a particular musculoskeletal injury. However, such an assessment may fail to uncover important underlying causes that stem from abnormal gait mechanics. A focused dynamic assessment of gait can be performed in a clinic hallway or using a treadmill. In addition, high-quality video capability is available on many smart phones or handheld devices, enabling more careful review of a patient's gait. Such gait analysis may provide important insights into the cause of a patient's symptoms. However, despite a plethora of practitioners and clinics that purport to correlate "gait analysis" findings with injury, there is currently no standard method for real-time clinical gait analysis in adults [1].

The term "gait analysis" encompasses a broad spectrum of potential assessment strategies used to evaluate normal and abnormal gait, both walking and running. Such assessments range from simple observation to sophisticated computer analysis of biomechanics. This topic is intended to help general clinicians and primary care sports medicine physicians understand how to perform a basic analysis of a patient's normal walking and running gait and to recognize some common gait abnormalities. It is not intended to address all clinical variations. Such techniques as computer-assisted gait analysis, force platforms, pressure sensors, and other sophisticated modes of analysis are beyond the scope of this topic, as is the assessment of complex pathologic conditions, including cerebral palsy, other pediatric neuropathic gait patterns, and gait involving use of a prosthetic limb [2]. Specific injuries that may stem from abnormal gait patterns are reviewed in greater detail separately. (See "Running injuries of the lower extremities: Risk factors and prevention" and "Overview of foot anatomy and biomechanics and assessment of foot pain in adults" and "Overview of stress fractures" and "Stress fractures of the tibia and fibula" and "Hamstring muscle and tendon injuries" and "Patellofemoral pain" and "Iliotibial band syndrome".)

GAIT CYCLE BASICS — The gait cycle is the repetitive pattern of walking or running movement (figure 1). Each complete gait cycle, or stride, begins when one foot makes initial contact with the ground, progressing through each phase of gait (see below), and ending when the same foot again makes contact. For walking, each stride is subdivided into a stance phase and swing phase for each foot. For running, a float phase is added. Each phase and its subdivisions are briefly described below:

●Stance phase: Period during gait when the foot is on the ground.

•Contact, including foot strike and early stance

•Mid-stance

•Terminal or late stance, including push-off and transition to swing phase

●Swing phase: Period during gait when the foot is off the ground, transitioning between stance phases.

•Early swing, including acceleration of non-stance leg

•Mid-swing

•Late swing, including deceleration of non-stance leg

●Float phase: Period during running gait only when neither foot is on the ground. Occurs after completion of push-off.

PREPARATION FOR GAIT ASSESSMENT — Important reasons for assessing a patient's gait, particularly in runners, include the following [3]:

●To identify poor running mechanics that may contribute to current symptoms or predispose to injury.

●To look for abnormal movement patterns that help to confirm particular pathologic conditions or injury, or to rule them out by the absence of such patterns.

The gait examination is best performed with the patient clothed appropriately so that the limbs and all important landmarks are easily seen. A tee shirt and running shorts work well. We begin the examination by assessing the patient's posture, joint motion, and strength. Once this is completed, we systematically observe the patient's gait as described below. A table summarizing conditions associated with particular gait findings is provided (table 1).

PRELIMINARY PHYSICAL EXAMINATION BEFORE GAIT ASSESSMENT — Before observing the patient's dynamic gait, we perform a focused examination looking for signs consistent with underlying conditions or injuries that may be the source of pain. This examination includes:

●Inspection (eg, posture, alignment, foot structure, leg length)

●Assessment of joint motion

●Targeted assessment of muscle length and flexibility

●Muscle strength testing

Inspection — The clinician should inspect the patient's posture from the front, both sides, and back looking for any asymmetries or signs of injury. Things to focus on are summarized in the following inspection checklist:

●General posture (figure 2)

●Shoulder height (should be symmetric) (picture 1)

●Spinal alignment (picture 2)

●Arm position

●Pelvis – Anterior and posterior superior iliac spines (ASIS and PSIS); gluteal folds (height should be symmetric) (picture 3)

●Hip – Internal rotation/external rotation (picture 4); greater trochanters (height and orientation should be symmetric) (picture 5)

●Knee – Genu varus (picture 6)/genu valgus; patellar tilt (rotation inward (picture 7) or outward); genu recurvatum (figure 3)

●Tibial varus (tibia curved outwards from midline) (picture 8)

●Lower extremity joint alignment (picture 9)

●External tibial torsion (picture 10)

●Heel varus/valgus (picture 11)

●Foot pronation (picture 12)/supination

●Pes cavus (high arch) (picture 13)/pes planus (flatfoot) (picture 14)

●Toe-in/toe-out (picture 15)

●Forefoot deformities (eg, bunion (picture 16))

Look for muscle atrophy, particularly in patients who have recently sustained an injury or undergone surgery. Specifically, look for atrophy of the gluteals, quadriceps, and gastrocnemius muscles. Achilles tendon thickening or nodules may be noted. Consider internal and external rotation of the knee, sometimes referred to as "patella squinting" (patella tilts inward – internal rotation (picture 7)) or "frog eyed" patella (patella tilts outward – external rotation). Look for tibial varus, in which the angle of the tibia is curved outward relative to a perpendicular line from the torso to the ground (picture 8) [4].

Inspect the arch of the foot for pes cavus (high arch) (picture 13) or pes planus (flatfoot) (picture 17), metatarsal break (abnormally short or long great toe), and metatarsophalangeal (MTP) deformities such as hallux valgus (bunion) (picture 16). Note any external or internal rotation of the foot: toe-out or toe-in. Are the feet asymmetric in any way? Assess the Fick angle: extent to which there is "toe-out" deviation from the sagittal plane (figure 4). This angle can be affected by hip position, tibial torsion, or excessive pronation in the foot.

The most common static abnormality associated with gait-related injury is limb length discrepancy [5-7]. Visual estimation of limb length difference is best done at this stage of the examination (picture 3). If a leg length discrepancy exists, one hip usually appears lower than the other. If any asymmetry appears to be present, careful leg length measurements should be taken. One simple technique for doing so entails ensuring the pelvis is level and then measuring the distance from the ASIS to the medial malleolus while the patient lies supine (picture 18). If the pelvis is not level, pelvic rotation can cause a pseudo leg length inequality when measurements are taken.

Joint motion — Normal joint range of motion (ROM) is needed for smooth, symmetric gait, and to help dissipate ground reaction forces. Running requires greater joint motion than walking [8]. Inadequate motion at any joint within a closed kinetic chain unavoidably leads to the transfer of ground reaction forces to other sites within that chain, a process that may contribute to injury.

ROM is typically assessed using open chain movements while the patient is seated or lying on an examination table [9]. Motion of the hips, knees, ankles, and first metatarsophalangeal joints should be assessed (table 2). Assessment of joint motion necessarily entails some assessment of the flexibility of the muscles that move the joint in question. However, more focused assessment of a muscle or muscle group may be needed. Detailed assessment of individual joints is reviewed separately. (See "Musculoskeletal examination of the hip and groin" and "Physical examination of the knee" and "Ankle fractures in adults", section on 'Clinical anatomy' and "Overview of foot anatomy and biomechanics and assessment of foot pain in adults".)

Although performed while the patient is stationary and non-weightbearing, open chain joint assessments accurately reflect joint mobility during movement in most cases. In addition, it is useful to have the patient perform closed chain movements to assess mobility when the feet are planted and bearing weight, as this more closely approximates joint mobility during gait. As an example, the clinician can ask the patient to perform a full, body weight squat (picture 19). Additional movements to assess joint mobility, symmetry in movement, and strength, include stepping down from a step or bench (picture 20), a single leg squat (picture 21), and bend and reach.

When assessing joint motion, keep in mind the effect of major muscles that cross two joints. As an example, knee flexion is restricted by the rectus femoris if the hip is simultaneously extended, as the rectus femoris crosses both the knee and the hip. Likewise, ankle motion is affected by knee extension or flexion, as the gastrocnemius crosses both the ankle and knee. The clinician needs to distinguish between joint motion limitations due to soft tissue constraints versus mechanical restrictions (eg, joint effusion, meniscal tear, bone spurs).

Muscle strength — A cursory evaluation of strength may alert the clinician to injury, myopathy, or a neurologic contribution to gait abnormality. As a practical matter, the strength examination is usually performed with manual muscle testing (MMT). Testing should include assessment of hip abduction (picture 22), adduction (picture 23) and flexion (picture 24), and knee flexion (picture 25) and extension (picture 26). MMT is reviewed separately. (See "Muscle examination in the evaluation of weakness", section on 'Manual muscle strength testing'.)

Of note, the MMT scale has several limitations, particularly when assessing strength for gait. One is that strength is assessed in one position and a muscle's strength varies along its range of motion. A second is that the assessment is performed using open kinetic chain movements, whereas most lower extremity muscles perform tasks (eg, gait) in a closed kinetic chain [10,11]. The load applied to the muscle may be markedly greater in a closed kinetic chain movement.

When an examination using open-chain movements suggests weakness, an examination using closed-chain repetitive movement may confirm the finding (eg, repetitive heel raises for gastrocnemius weakness).

GENERAL APPROACH TO GAIT ASSESSMENT — The dynamic gait examination can be as simple as observing the patient walk or run in a hallway [12]. If a treadmill is available, the clinician can observe walking or running across a range of speeds that may elicit abnormalities not seen at a slower pace. Although there are subtle differences in gait when using a treadmill compared with overland running, they are minimal and generally not clinically significant [13]. Impact on the tibia (tibial shock) is lower with treadmill versus overground running, but no studies report significant injury differences between the two [14].  

A skilled clinician may be able to identify asymmetries and other abnormalities with the naked eye. Nevertheless, by using simple motion capture video with an iPad, smartphone, or comparable device, and performing a careful review of slow motion video, clinicians are better able to identify a host of potential mechanical problems that may be missed by the naked eye. Standardizing the video capture and then uploading via telehealth provides another way to assess gait concerns [15]. Applications for obtaining angular measurements and other mechanical analyses are available [3]. These strategies allow real-time review with the patient. A table summarizing conditions associated with particular gait findings is provided (table 1).

Dynamic gait is assessed from the side (sagittal plane), front, and rear (coronal plane) (movie 1 and movie 2 and movie 3 and movie 4).

It is best that the clinician establish a systematic method for observing a patient's gait that is used for every examination. This approach helps to ensure that all the important elements of a patient's gait are observed and possible abnormalities identified. We observe the elements of gait in the following sequence:

●Arm swing

●Head and trunk position and movement

●Pelvic position and rotation

●Hip position and motion

●Knee position and motion

●Ankle and foot position (pronation, neutral, supination) and motion

●Overall gait dynamics

We find it helpful to focus on one element of gait through several full cycles, and then move on to the next element. As an example, we may concentrate on the right leg during its swing phase for three to four cycles, and then observe the left leg during swing phase for several cycles, and then compare the two, before moving on to the next element.

Gait observation checklist — A checklist suitable for use during patient evaluation that summarizes the elements to observe during gait assessment is provided. The checklist includes key clinical questions for each element assessed (table 3).

ASSESSMENT OF WALKING AND RUNNING GAIT — The following sections describe the key points of observation for walking and running gait, organized anatomically. To make best use of this discussion, we suggest reviewing the overall approach described above, including the video clips demonstrating normal gait, and the observation checklist. A table summarizing conditions associated with particular gait findings is provided (table 1). (See 'General approach to gait assessment' above.)

Upper body including head

Walking — Begin the walking gait examination by observing the upper body. Look at the motion of the head, trunk, and arms. The head moves vertically, although only slightly, in a sinusoidal pattern, with minimal if any side-to-side sway or rotation. Shoulder height and arm swing should be symmetric [16]. Movement of the torso in the coronal plane should be minimal and symmetric [17]. Normal walking gait is seen in the following videos (movie 2 and movie 1).

Each arm provides counterbalance to the contralateral lower extremity as they swing, and the movements of these limbs should be synchronized. This synchrony minimizes any twisting of the trunk or pelvis in the transverse plane, enabling maximal stride length [18-20]. Exaggerated sway to the stance side after touchdown is associated with ipsilateral knee pain, hip abductor weakness, spinal deformity, low back pain, and other problems [21].

Running — A person's center of mass becomes lower during running, and the body leans forward. Head position remains relatively level without excessive vertical motion (bobbing) or lateral flexion. Arm swing is more exaggerated but remains symmetric (movie 3 and movie 5). From the front, observe the symmetry and extent of hand and arm elevation, and from behind, the elbow position. The hands and fingers should maintain a relaxed, slightly cupped position without excessive gripping or rigidly straight fingers.

Pelvis

Walking — Pelvic movement during gait should be smooth, symmetric, and unexaggerated. From the rear, look closely for pelvic tilt. Observe one side of the pelvis before directing attention to the other. Excessive lateral pelvic tilt may be caused by weakness of the contralateral hip abductors (eg, gluteus medius) (movie 6).

Next, examine the pelvis from the side. The pelvis is rotated posteriorly at foot-strike, then begins to rotate anteriorly during the stance phase, reaching its maximum after toe-off [17]. The pelvis provides stability for the lower extremities during gait. Although normally there is some movement of the pelvis in all three planes, excessive pelvic motion in any plane or asymmetric movement can contribute to injury, such as hamstring strains (picture 27) [22,23].

Running — Seen from the rear, the pelvis drops and rotates during running, but the increase in motion is small compared with walking. Pelvic movement should remain smooth, symmetric, and unexaggerated (movie 7). Most importantly, observe the symmetry and degree of pelvic drop (picture 27). Excessive drop suggests weakness of the hip abductors (picture 28) [24].

Hip

Walking — From the side, observe hip flexion and extension (picture 29). Note any differences in range of motion and timing. A limp alters timing (patient spends more time on the injured extremity) and suggests a painful limb.

The weightbearing hip passively adducts at initial ground contact. Then at late stance, the gluteus medius actively abducts the femur (acting on the pelvis) in preparation for accepting the load of bodyweight at contralateral touch down [8]. Seen in the coronal plane, the supporting hip passively adducts maximally at mid-stance (picture 28). This adduction of the hip relative to the pelvis is passive because gravity causes the swing (unsupported) side of the pelvis to drop. This drop is best appreciated by observing the lateral pelvic tilt towards the swing side (picture 30). With normal hip adduction, the lower extremity, most notably the knee, should not reach midline.

Running — Hip motion during running is best appreciated from the side. Observe the degree of hip flexion (look for knee lift), and the symmetry of movement. During running, the hip begins to extend before foot contact (picture 31). Maximum hip extension occurs just before toe-off. Hip extension and anterior pelvic tilt combine to provide maximal time for foot contact with the ground (picture 32). Runners may compensate for limited hip extension by increasing their anterior pelvic tilt, thereby causing increased lumbar lordosis. Over time, this adaptation may produce low back pain or hamstring tendinopathy [25]. In addition, excessive hip adduction is associated with tibial stress fractures [26-29].

Knee and leg

Walking — From the side, observe, knee elevation, knee flexion at foot contact, and knee extension at toe-off. In the sagittal plane, the knee is slightly flexed (approximately 20 to 25 degrees) at initial contact. As the contact phase continues and impact increases, the knee flexes further to absorb more of the ground reaction force. On the stance leg, maximal flexion (approximately 45 degrees) occurs as the opposite knee passes it during its mid-swing. Knee flexion should also be observed during the swing phase. Knee extension occurs during the late stance phase, and then again during late swing phase. Normal motion of the knee during walking is seen in the following video (movie 8).

It is important to observe knee alignment and motion in the coronal plane. Knee valgus, seen as an inward deviation of the knee, is associated with patellofemoral pain and other conditions [30]. Knee valgus is usually accompanied by knee internal rotation. Excessive valgus can be observed by focusing on the distance between the knees at mid-stance as the knees cross, and noting knee position relative to a line drawn from the hip to the ankle (picture 33) [3,21].

Look for outward tibial tilt (tibial varus) (picture 34). This occurs when the proximal tibia is positioned away from the midline and the distal tibia toward the midline. Excessive outward tibial tilt correlates with increased torsional loads placed on the tibia [31].

Running — Observing the knee from the side enables the clinician to assess the knee flexion angle at foot contact. This angle is typically 20 degrees when walking and 30 degrees when running. The angle at contact varies little with increased running speed. A straighter knee at contact is associated with over-striding and more forceful heel contact [21].

During the stance phase, maximal knee flexion (typically 45 degrees) occurs at mid-stance when the knees cross one another. Knee flexion is much greater during the swing phase of running, reaching 130 degrees in some. While the knee may reach near full extension at toe-off when walking, it remains slightly flexed at terminal stance when running.

Knee motion in the coronal plane can be evaluated from the front or rear. Observe the knee relative to a line from the hip to the ankle. Knee excursion medial of this line (valgus knee) (movie 9) is associated with patellofemoral pain and other conditions [30].

Foot and ankle

Walking — Some authors suggest a "bottom up" scheme for gait assessment [8]. This is not required, and is not our approach, but the suggestion reflects the important effect that foot contact has on the kinetic chain proximally during gait.

Observe rearfoot and ankle motion from the front, rear, and both sides. A view from the front is most helpful for determining whether the patient is toeing in or out (picture 15). Look for symmetry and the degree of rotation, if present. The Fick angle reflects foot external rotation relative to the line of direct forward progress, and is normally 5 to 18 degrees (figure 4). If this angle is asymmetric or excessive, the examiner should attempt to determine the source of rotation: foot, tibia, femur, or hip.

The side view is used to assess ankle dorsiflexion and plantarflexion, stride length, and toe-off symmetry. Restricted ankle motion, perhaps a result of previous ankle sprain or arthritis, usually causes a shorter stride on the affected side. This manifests as a quickened or premature lift off of the foot when compared with the unaffected side.

From the rear, observe heel contact position, heel valgus or varus, and the timing of heel lift. At contact, the heel is typically varus (or supinated), and seen as landing on the posterior-lateral corner of the foot or shoe. This causes the most common shoe wear pattern (on rear/lateral part of sole). The heel may be valgus (or rearfoot pronated) due to a variety of structural problems, such as posterior tibial tendon dysfunction, rigid flatfoot (pes planus), or tarsal coalition. Gait deviations, such as excessive rearfoot motion, are associated with plantar heel pain [32]. Heel lift occurs midway through the stance phase of gait. An early lift may occur in the presence of a tight gastrocnemius muscle or Achilles tendon, ankle joint restriction, or neurologic conditions such as mild cerebral palsy.

Running — When assessing the foot and ankle during running, begin by identifying the foot strike pattern. From the side, observe which part of the foot makes initial contact with the ground. Each foot will move through a stance phase and a swing phase; the float phase is when both feet are off the ground (movie 10).

The magnitude and pattern of ground reaction forces is largely determined by the foot-strike pattern, of which there are three basic types [33]:

●Rearfoot strike pattern ‒ In the rearfoot pattern, the posterior-lateral heel makes first contact with the ground while the foot is dorsiflexed. The rearfoot is typically inverted prior to contact and then promptly everts or pronates after contact. This pronation helps attenuate impact forces.

●Midfoot strike pattern ‒ In the midfoot pattern, initial ground contact is made with the portion of the midfoot overlying the metatarsal heads, followed immediately by the heel (picture 35). The foot is subtly plantar-flexed, instead of dorsiflexed, at contact.

●Forefoot strike pattern – In the forefoot pattern, the foot is positioned in plantar flexion, and often supination, at contact. The forefoot makes initial contact with the ground, but this is not followed by heel contact (picture 35). A pronounced forefoot varus strike is associated with an increased risk for running-related injury.

A rearfoot strike pattern produces rapid and relatively high peak vertical ground reaction forces, whereas a forefoot pattern produces a slower rate of rise in ground reaction forces and eliminates the initial spike in such forces seen with a rearfoot strike [34]. Of note, a forefoot strike made with a rigid cavus foot also generates high peak forces [35]. High vertical loading rates and high peak ground reaction forces are associated with stress fractures and possibly other injuries [27]. Although some associate a rearfoot strike pattern with injury, for the uninjured runner with a rearfoot strike pattern, purposefully adopting a non-rearfoot strike is not necessary [36].

Once the foot strike pattern is determined, the key aspect of foot and ankle movement to observe is the degree of pronation, in particular whether pronation is associated with too much or too rapid an inward motion of the foot and ankle (picture 12). This is best observed from the rear during mid-stance. The foot pronates maximally halfway through the stance phase (movie 11) [37,38]. To gauge pronation, watch the heel movement, and look for navicular drop (arch collapse) and forefoot abduction (or "toe-out") (picture 12).

Heel position and movement is determined by comparing it to the lower leg. To do so, extend two imaginary vertical lines, one that bisects the lower leg and another that bisects the heel at mid-stance. If the angle formed by these lines is oriented laterally, the heel is in valgus; if medially, the heel is in varus (picture 11). Determining whether pronation is excessive without computer or video assistance is somewhat subjective. The clinician can compare sides for symmetry and estimate the amount of heel eversion and arch flattening as mild, moderate, or severe (movie 12).

Excessive valgus angulation can place stress on the posterior tibial tendon, plantar fascia, and lower leg muscles. As noted above, the heel is usually slightly inverted at contact, then it rapidly everts. Foot structure, intrinsic and extrinsic foot muscles, and conditions affecting more proximal structures, such as genu valgus, can all play a role in excessive pronation. When genu valgus contributes to pronation, the alignment of the ankle and foot may appear normal or minimally angulated. However, in some instances both genu valgus and excessive foot pronation coexist.

Arch descent is a readily visible component of normal pronation. This can be seen from a posterior or medial perspective. A small degree of navicular drop seen in the idealized neutral foot is normal. The pes planus foot ("flatfoot" (picture 17)) demonstrates a marked navicular drop, consistent with its flat appearance (picture 12). A dynamic navicular drop is greatly exaggerated in the "hyperpronated" (or rigidly flat-footed) individual.

Excessive heel varus is present with a supinated (ie, pes cavus or high arch) foot structure. If the heel remains in varus and does not transition to slight valgus after heel contact, the examiner should consider conditions such as a tarsal coalition. Many tarsal coalitions involve bridging between the calcaneus or talus and one of the tarsal bones (eg, navicular). Such a bridge blocks the normal rotation that takes place between the midfoot and rearfoot at Chopart's joint. The pes cavus foot is sometimes associated with a rigidly plantar-flexed first ray (picture 13). Such a rigid, high arch lacks appropriate pronation through mid-stance [39].

Watching the patient from the front and rear, observe the transfer of weight from the lateral forefoot to the first ray and then through the great toe at toe-off. This sequence requires normal metatarsal anatomy, first ray mobility, and motion at the first metatarsophalangeal (MTP) joint, and should appear smooth. First MTP motion restriction (eg, hallux rigidus, hallux limitus) can affect the function of the entire lower extremity during gait [40]. Excessive first ray motion may manifest as persistent pronation late into the toe-off phase. This can increase the impact at the first MTP joint and cause inappropriate weight transfer to the lesser metatarsals late in push-off, which may contribute to pathology at the first MTP joint, such as hallux rigidus and hallux valgus [41]. (See "Evaluation, diagnosis, and select management of common causes of forefoot pain in adults", section on 'Hallux rigidus and hallux limitus'.)

SUMMARY AND RECOMMENDATIONS

●Gait cycle – The gait cycle is the repetitive pattern of walking or running movement. It is described in the text and the accompanying picture (figure 1). Assessment of dynamic gait can provide insight into possible causes of a patient's symptoms or make apparent abnormal movement patterns that may contribute to injury. (See 'Gait cycle basics' above and 'Preparation for gait assessment' above.)

●History and examination – Prior to assessing a patient's gait, the clinician should obtain a history and perform a focused examination, including:

•Inspection (eg, posture, alignment, foot structure, leg length)

•Assessment of joint motion

•Targeted assessment of muscle length and flexibility

•Muscle strength testing (see 'Preliminary physical examination before gait assessment' above)

●Systematic gait assessment – Gait assessment can be performed in a hallway, outdoors, or on a treadmill. By using the motion capture video feature found on many smartphones or other devices, and performing a careful review of slow motion video, clinicians can identify abnormal movements that may be missed by the naked eye. Dynamic gait is assessed from the side (sagittal plane), front, and rear (coronal plane) (movie 1 and movie 2 and movie 3 and movie 4). (See 'General approach to gait assessment' above.)

It is best to establish a systematic method for observing a patient's gait that is used for every examination. We observe the elements of gait in the sequence outlined below. In addition, a checklist suitable for use during patient evaluation that summarizes the elements to observe during gait assessment is provided (table 3). Details pertaining to each part of the assessment are described in the text and accompanied by multiple still and moving images to illustrate important elements. (See 'Assessment of walking and running gait' above.)

•Arm swing

•Head and trunk position and movement

•Pelvic position and rotation

•Hip position and motion

•Knee position and motion

•Ankle and foot position (pronation, neutral, supination) and motion

•Overall gait dynamics