May 2018

PERSPECTIVE: Physical Therapy


By Ken Johnson, PT

Mr. Johnson is director of outpatient rehabilitation therapy services at Johns Hopkins Rehabilitation Network in Baltimore, Maryland. He has disclosed no relevant relationships.

LER: What is the most common cause of chronic foot, ankle, or knee symptoms that you see in your physical therapy practice?

KJ: Because the patient population in my practice as a physical therapist at the Johns Hopkins Rehabilitation Network is comprised mainly of professional and elite athletes as well as recreational runners, we see many patients with chronic overuse types of injuries, such as Achilles tendinopathies, heel pain, and stress reactions. Interspersed with these overuse or patho-mechanical types of injuries are more acute, traumatic conditions such as ligamentous strains, fractures, and post-operative reconstructive surgery. For this discussion, I will focus primarily on the chronic aches and pains that affect a person’s mobility and activities of daily (and desired) living.

Because these chronic pathologies are typically multifactorial in nature, identifying a solitary solution for correction is often a challenge. While our team at Johns Hopkins uses well-established evidence-based clinical practice guidelines for the evaluation and treatment of lower limb pathologies, we are excited about the development of new strategies to enhance evaluations and optimize the soft-tissue healing and recovery process.

LER: What tests do you perform?

KJ:Our testing battery is performed over 2 days. During the first visit, our physical therapist will focus on the self-reported functional measures such as the functional ankle ability measure, ambulatory measure of post-acute care, and lower-extremity functional scale. These tools involve a series of specific questions related to pain, function, and disability in an effort to establish an objective baseline from which we measure progress and detectable change.

Following the patient’s history and a review of systems, we conduct a standard musculoskeletal evaluation of foot posture, structural integrity of foot, joint mobility, observational gait and balance, and strength. For strength testing, in addition to traditional manual muscle testing, we use a hand-held dynamometer and focus on muscles of the hip that stabilize the lower limb during activity.

LER: What computerized tests do you employ?

KJ: We focus our computerized testing on hip abductor, rotator, and extensor muscle groups because these are used for stability and locomotion. Recent research suggests that manual muscle testing may not accurately represent strength differences. In one study, master clinicians were unable to detect right-left strength differences greater than 30% with their hands. Therefore, the dynamometer we use allows us to calculate a “body relative” measure. If a subject weighing 100 lb generates 50 lb of force at the hip, we would say that hip strength is 50% of body weight; an ideal target percentage. However, if that same person weighed 200 lb, we would say that hip is 25% of their body weight, which is 50% below our target value and in need of strengthening.

Isolated muscle testing evaluates strength, but another approach is functional testing of movement patterning. For example, repetitions of heel raises with the knee straight and then bent, observation of deep squatting, single-leg step-down, and in-line lunge. Often the use of appropriate standardized test protocols, such as the functional movement screen, selective function movement assessment, original strength screen and assessment, or Y-balance test, are critical tests in the active patient.

The second part of our evaluation involves an instrumented gait analysis with high-speed motion capture. The treadmill has 7,000 sensors in the deck of the treadmill and achieves 18 mph. The motion analysis system captures the running motion at 120 frames per second, using a colored-LED tracking system that records and displays body and limb segment motions in real time. From the motion capture, we analyze an additional 30 dependent measures.

I find during this time that patients who participated in physical therapy elsewhere will notice our distinctly different problem-solving techniques.

LER: What are the key indicators from computerized tests?

KJ: Key indicators from the instrumented treadmill that we look for in runners include:

  • foot rotational position at mid-stance
  • step symmetry
  • cadence
  • time in stance
  • center of pressure tracking
  • rearfoot/midfoot/forefoot force and pressure.

High-speed motion capture recording body position and movement also reveals heel distance from center of mass and tibia angle relative to ground at initial contact; trunk position, hip-knee angle ratios, and ankle dorsiflexion angle at mid-stance; hip, knee, ankle extension angles at terminal stance; and vertical displacement.

LER: How do you use all this information to manage the patient’s condition?

KJ: A lot of information from the comprehensive assessment feeds directly to our management strategy. Using a relatively standardized testing sequence helps identify outlier patterns such as below-target hip strength, asymmetry, low-scoring function movement assessment, cadence below 170 steps per minute, etc.

Early in my career, I took a very biomechanical, manual therapy, and exercise-based approach. With the emergence of anti-gravity treadmills, we began to reintroduce running sooner because we could offload body weight by as much as 80%.

Over time I learned that no matter how complete the physical exam, how flexible and friendly we were with scheduling, or how dazzled patients were with sophisticated gait analysis, clients would still cancel appointments, fail to perform corrective exercises, or disengage from therapy all together. The fix often is not fast enough, and only a minority of patients possess the discipline to carry on for the 6-8 weeks required to increase strength. Patients are not seeking to correct poor mechanics; they seek a solution to the pain that limits their daily and recreational activities.

Today, in addition to a corrective exercise program and manual therapy, we aim to manage the healing transition from inflammation and pain to proliferation and remodeling. We do this by introducing different forms of mechanotransduction such as instrument-assisted soft tissue mobilization and myofascial acoustic compression therapy, followed by a negative pressure decongestion of the fascia and lymphatic system with mechanically assisted manual lymphatic drainage. After facilitating an increase in blood flow to the treatment area and clearing the lymphatic drainage pathway, photo-biostimulation with a super-pulsed laser produces a photochemical reaction resulting in increased release of ATP within the cell to accelerate proliferation for a 24 to 48-hour period following treatment.

This combination of technology and technique sequencing results in a therapeutic foundation that may be treated with dynamic taping techniques, rigid strapping, and/or orthoses as appropriate. This approach of course requires incremental steps of patient education and reflection to allow the patient to relate every aspect of treatment and subsequent progress to the baseline assessment and behaviors, mechanics, or environmental factors that led to the initial breakdown.

Even a systematic advanced approach is not a guarantee for success, but the framework facilitates the dialogue between the physical therapist, physician, surgeon, or podiatrist to ensure the patient is at the center of our care plan.

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