Chapter 7 Evaluation of Gait

Introduction “Walking has been described as a series of narrowly averted catastrophes where the body falls forward, then the legs move under the body to establish a new base of support.” Gait analysis Functional evaluation of walking or running style Classic LE functional test Gait evaluation identifies Functional limitations Chronic pain related to physical activity

Gait Terminology Step—sequence of events from a specific point in the gait on one extremity to the same point in the opposite extremity Step length—distance traveled between the initial contacts of the right and left foot Step width—distance between the points of contact of both feet Stride—two sequential steps

Gait Terminology Cadence—number of steps taken per unit time (i.e., steps per minute) Adults average = 107 +/– 2.7 steps per minute Velocity—distance covered per unit time (i.e., m/sec) Gait velocity—meters per second Gait cadence—steps per minute

Gait Terminology Stride time—time required to complete a single stride Stride length—linear distance covered in one stride

Gait Terminology Ground reaction force (GRF) Center of pressure (CoP) Contact of the foot with the ground creates force yielding vertical, anteroposterior (A/P), and mediolateral (M/L) components Center of pressure (CoP) Shows the path of the pressure point under the foot during gait

Phases of the Gait Cycle With the right (facing) limb as an example, two distinct phases occur Weight-bearing (WB) stance phase Non–weight-bearing (NWB) swing phase Legs alternate between supportive (stance) and nonsupportive (swing) Two points the body is supported by a single leg Midstance Terminal stance

Phases of Gait

Walking Gait Phases Efficient gait Center of gravity Minimal side-to-side motion Maximal forward motion Body rises and falls approx. 5 cm Center of gravity Path is a sinusoidal curve.

More Terminology… Kinematic—the characteristics of movement related to time and space (e.g., range of motion, velocity, and acceleration); the effects of joint action Kinetic—the forces being analyzed; the causes of joint action

Stance Phase Five periods Initial contact Loading response Midstance Terminal stance Preswing The weight-bearing phase of gait; begins on initial contact with the surface and ends when contact is broken. High-energy phase Kinetic energy is absorbed from the ground and transferred up the kinetic chain.

Swing Phase The non–weight-bearing phase of gait; begins at the instant the foot leaves the surface and ends just before initial contact. 38% of gait cycle Low-energy phase Three periods Initial swing Midswing Terminal swing

Muscle Activity During Gait Understanding muscle activity and ROM aids in identifying impairments and compensations associated with pathology.

Running Gait Cycle Differences from walking gait Flight phase—neither foot is in contact with a supportive surface No period of double limb support Vertical GRF 2.0–6.0 x the body weight Stance phase time As speed increases there are changes in Arm swing Stride length Cadence Knee flexion ROM Muscular force Speed of contraction Less up and down motion

Ground Reaction Forces (A) During walking; (B) during running.

Stance Phase of Running Gait Hip: Flexed to 50° and moves to extension Knee: Flexed to 30°, moves to 50° of flexion, and then moves into extension Ankle: DF to 25° then moves to PF Subtalar: Supinates, pronates, then supinates again Loading response and midstance period occur more rapidly.

Swing Phase of Running Gait Clears the NWB limb over the ground and positions the foot to accept WB. Probability of injury is < stance phase Hamstrings eccentrically contract to slow knee extension. Swing phase Hip: 10° of extension to 50° to 55° of flexion Knee: Full extension to 125° of flexion (sprinters) and to 40° of flexion (preparing for contact) Ankle: 25° of PF to 20° of DF

Gait Evaluation Two basic methods Qualitative assessment Observational gait analysis (OGA) Quantitative assessment

Quantitative Gait Analysis

Observational Gait Analysis Poor to moderate reliability Improves with experience, video equipment, and use of OGA tools Good observation Auditory clues Observe left and right sides separately Self-selected pace

Observational Gait Analysis Guidelines Prepare the area and materials ahead of time. Avoid clutter in the viewing background. Have the patient wear clothing that does not restrict viewing of joints. Ensure that the patient is at a self-selected walking pace; otherwise, gait will be altered.

Observational Gait Analysis Guidelines Position yourself so you can view the individual segments. Observe the subject from multiple views but not from an oblique angle. Look at the individual body parts first, then the whole body, then the individual parts again.

Observational Gait Analysis Guidelines Conduct multiple observations or trials. Conduct the analysis with the patient barefoot and wearing shoes. Label all video files.

Observational Gait Analysis Findings

Interventions Cue words or phrases during gait or exercise to improve gait Footprints on the floor for visual feedback on technique Hand on a body segment for kinesthetic feedback Orthotics Different shoes Strength training exercises Flexibility or ROM exercises

Excessive Pronation Pronation is necessary for shock absorption. Pronation through a range > 15.5° has been linked with LE injury. Related to Genu valgum Leg-length discrepancy Pes planus Hip musculature imbalance Soft midsoles in shoes Exhibits Calcaneal eversion Lowering and elongation of medial longitudinal arch Increased pressure on the first MTP Wear pattern on shoe Medial knee pain

Toe In or Toe Out Found in midstance or just after push-off Causes Tibial rotation Hip rotation Excessive pronation during stance (places limb medial, lower leg compensates = toe out) Toe in Stress on lateral soft tissues (peroneus longus) Toe out Stress on medial and plantar structures

Shortened Step Length Causes Pain (hip, knee, or ankle) Shorten stride so as to not make symptoms worse with larger impacts on contact Inadequate push-off (triceps surae) Inadequate pull-off (hip flexors)

Shortened Stance Time Antalgic gait pattern (i.e., “limp“) Causes Pain Acute or chronic Avoid load absorption Recommendations Crutches Protective brace

Unequal Hip Height Causes Leg-length discrepancy Weak gluteus medius Trendelenburg gait

Asymmetrical Arm Swing Arm swing counterbalances hips and pelvis Larger arm swing in running Causes Upper extremity injury Leg-length discrepancies Spine dysfunction Scoliosis Limited or exaggerated motion on one side of hip or pelvis

Plantarflexed Ankle at Initial Contact Causes Gastrocnemius spasticity Can only keep ankle in PF Drop foot Nerve pathology that prevents DF Hamstring pathology Keeping muscle short eases pain Knee joint pathology

Flat Foot Stance Exhibits Causes Absence of initial heel contact PF at the ankle is avoided in terminal stance and preswing Causes Ankle sprain Gastocnemius sprain Soleus sprain

Inadequate Ankle Plantarflexion Angle at Push-Off Insufficient ankle PF at push-off Causes Inadequate strength (triceps surae) Acute ankle sprain (pain and swelling) Forefoot pathology

Excessive Knee Flexion Ankle at Contact Normally knee is near full extension at contact during walking (running 21° to 30°) Causes Pain Hamstring strain Hip adductor strain Tight hamstring or spasm Sciatic nerve pathology Herniated disk Piriformis syndrome

Inadequate Knee Flexion Angle During Stance Knee normally flexes to 20° during stance. Controlled by eccentric contraction of quadriceps muscle Causes Quadriceps pathology Knee joint pain

Inadequate Knee Flexion During Swing During the swing phase, knee normally is flexed to 30° to 60° during walking and over 90° during running Causes Hamstring pathology Strains Spasms Sciatica

Inadequate Hip Extension at Terminal Stance Normally, hip extends as the body is propelled forward. Causes Contracture of the hip flexors

Forward Trunk Angle Indicates Low back pathology For example, herniated disk Weak and painful hip flexors Weak ankle plantarflexors