Reviewed by Tyler Tice, PT, DPT, OCS, ATC

Introduction:

Running is one of the most popular forms of physical activity. However, the popularity of running is accompanied by a high prevalence of overuse injuries. Most injuries occur in the lower extremities, with a substantial proportion affecting the foot. These injuries are often linked to biomechanical factors such as impact loading, plantar pressure, and repetitive stress, particularly on the metatarsals and soft tissues of the foot. To address these issues, research has explored biomechanical modifications, such as cadence manipulation, as a strategy to reduce injury risk. Increasing cadence has been shown to decrease step length and ground reaction forces, potentially mitigating the forces implicated in injury development. This study specifically evaluates the effects of cadence manipulation on plantar loading in healthy runners, focusing on how these changes could influence injury prevention and management.

Methods:

Thirty-eight healthy recreational runners participated in this study. Participants met inclusion criteria requiring a minimum running distance of 12.87 km per week and no musculoskeletal injuries in the prior six months. Plantar loading data were collected during treadmill running at participants’ preferred pace under three cadence conditions: preferred, 5% increased, and 5% decreased. Each trial was randomized to minimize fatigue effects, with data collected for 30 strides per condition.

Plantar loading variables analyzed included:

• Contact Time (CT): The duration of foot contact with the ground.
• Peak Force (PF): Maximum force exerted during a foot strike.
• Force Time Integral (FTI): Total force exerted over the contact period.
• Peak Pressure (PP): Maximum pressure exerted on the plantar surface.
• Pressure Time Integral (PTI): Total pressure applied over time.

These variables were measured for the total foot and four specific regions: heel, medial metatarsal, central metatarsal, and lateral metatarsal.

Results:

The study found that cadence manipulation significantly influenced plantar loading patterns:

1. Increased Cadence (+5%):
   • Decreased CT, PF, and PTI for the total foot and all foot regions.
   • Reduced heel loading, including lower pressure and force variables.
   • Lower metatarsal loading across medial, central, and lateral regions.
2. Decreased Cadence (-5%):
   • Increased CT and higher PF and PTI values in the heel and metatarsal regions.
   • Elevated total foot loading, with more pronounced force and pressure variables.

Discussion:

The results underscore the biomechanical benefits of increasing cadence during running. A faster cadence reduces plantar loading by decreasing contact time and ground reaction forces. Notably, this study refuted the hypothesis that increased cadence would elevate metatarsal loads; instead, all regions of the foot experienced reduced loading. These effects may be attributed to reduced vertical oscillation of the body’s center of mass and a decreased foot inclination angle at initial contact.

From a clinical perspective, cadence manipulation presents a promising strategy for reducing the risk of overuse injuries, such as plantar fasciitis, Achilles tendinopathy, and metatarsal stress fractures. By lowering repetitive loads on vulnerable foot structures, a 5% increase in cadence can mitigate the cumulative stress associated with long-distance running.

Conclusion:

This study highlights the potential of cadence manipulation as an effective tool for injury prevention and rehabilitation in runners. A modest 5% increase in cadence reduces plantar loading across all foot regions, suggesting that cadence training could be integrated into physical therapy protocols for managing running-related injuries. Given the small but meaningful biomechanical changes observed, cadence adjustments should be considered alongside other therapeutic interventions, such as strength training and gait retraining, to optimize treatment outcomes.

Implications for Physical Therapy:

The findings of this study have direct applications in physical therapy practice. For patients recovering from lower extremity injuries or seeking to prevent future injuries, cadence training offers an evidence-based intervention to reduce plantar stress and improve running mechanics. Physical therapists can use tools like metronomes or wearable devices to guide patients in cadence adjustments, ensuring gradual and sustainable changes in running form. Furthermore, cadence manipulation can complement traditional rehabilitation approaches, such as strengthening exercises for the intrinsic foot muscles and addressing biomechanical deficits in the kinetic chain. By incorporating cadence training into a comprehensive rehabilitation program, therapists can enhance patient outcomes, reduce injury recurrence, and promote safe, efficient running mechanics. This approach aligns with the growing emphasis on personalized and biomechanically informed physical therapy interventions.

1. Wellenkotter J, Kernozek T, Meardon S, Suchomel T. The Effects of Running Cadence Manipulation on Plantar Loading in Healthy Runners. International journal of sports medicine. 2014;35. doi:10.1055/s-0033-1363236

Reviewed by Tyler Tice, PT, DPT, OCS, ATC

Article:

Patellofemoral Pain Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability and Health From the Academy of Orthopaedic Physical Therapy of the American Physical Therapy Association

Introduction:

The orthopaedic section of the American Physical Therapy Association (APTA) published these clinical practice guidelines in 2019 to give recommendations to clinicians in the differential diagnosis, assessment and treatment of patellofemoral pain.

These recommendations are designed to fit into the International Classification of Functioning, Disability, and Health (ICF model) that was introduced by the World Health Organization (WHO) to improve clinician’s ability to appropriately treat and communicate with patients by including pathoanatomical, psychosocial and societal factors when assessing a patient’s wants and needs.

Methods: 

Content experts were appointed by the orthopedic section of the APTA to search the current literature for articles relating to the treatment, assessment and diagnosis of patellofemoral pain.  Articles included were taken from MEDLINE, Scopus, CINHAL, SPORTDiscus, and the Cochrane Library with dates ranging from 1960 to 2018.

The chosen articles were then categorized based on level of evidence where I represented the highest quality evidence and V represented expert opinion.  After the evidence was reviewed and ranked, the experts developed and ranked recommendations utilizing the information.  A ranked recommendations were based on strong evidence while F ranked recommendations were based on expert opinion.  These recommendations were further categorized into the following content areas; diagnosis, classification, examination, and interventions.

Results: 

After reviewing the available literature, the authors made the following recommendations:

Clinicians should use the reproduction of pain behind or around the patella during squatting or other motions that load the patellofemoral joint in a flexed position to help diagnose patellofemoral pain.

The following factors can be used to diagnose patellofemoral pain:  pain behind or around the patella, reproduction of pain when the patellofemoral joint is loaded in a flexed position, exclusion of all other conditions that can cause anterior knee pain including tibiofemoral pathologies.

Clinicians can use the patellar tilt test with the presence of hypomobility to support the diagnosis of patellofemoral pain.

Since there are no previously established classifications of patellofemoral pain, the authors propose the following 4 classifications:  overuse/overload without other impairments, muscle performance deficits, movement coordination deficits, and mobility impairments.

Clinicians should use the following patient reported outcome measures when assessing patients with suspected patellofemoral pain:  the Anterior Knee Pain Scale, the patellofemoral pain and osteoarthritis sub-scale of the Knee Injury and Osteoarthritis Outcome Score, the Visual Analog Scale, the Eng and Pierrynowski Questionnaire, the Numeric Pain Rating Scale.

Clinicians should use functional tests such as squats, or step downs that reproduce patellofemoral pain to assess a patient’s progress throughout an episode of care.

Clinicians may use body structure and function impairments such as joint hypomobility, muscle weakness and lack of muscle extensibility to assess progress throughout an episode of care.

Clinicians should employ an exercise approach that targets both hip and knee musculature.  During the early stages of therapy, exercises targeting the posterolateral hip musculature is preferred but as the plan of care continues, targeting knee musculature as well is essential.

Clinicians may use patellar taping in the early stages of rehabilitation with the goal of reducing pain to enhance exercise performance.  Evidence shows that this can be helpful early on but generally has no lasting impact on prognosis or symptoms.  Clinicians should not prescribe knee orthoses such as knee sleeves or braces for the treatment of patellofemoral pain.

Clinicians may prescribe prefabricated foot orthoses for patients with greater than normal foot pronation during the early stages of rehabilitation in concert with an exercise program.  There is limited evidence suggesting that custom foot orthoses are more effective than prefabricated foot orthoses.

Clinicians should not use electromyography-based biofeedback on medial vastii activity to augment quadriceps exercise therapy for the treatment of patellofemoral pain.  Clinicians should also not use visual biofeedback on lower extremity alignment during hip and knee targeted exercise during the treatment of patients with patellofemoral pain.

Clinicians may use gait retraining during running for multiple sessions to adopt gait changes during running for patients with patellofemoral pain.

Clinicians may use blood flow restriction plus high-repetition knee exercises for those with limited or painful resisted knee extension.

Clinicians should not use dry needling for the treatment of patellofemoral pain, however acupuncture may be used to reduce pain.  There is limited evidence that acupuncture is more effective than placebo so caution should be exercised with this recommendation.

Clinicians should not use joint mobilizations or manipulations as a stand-alone treatment for patellofemoral pain.  Clinicians should not use biophysical agents including ultrasound, cryotherapy, phonophoresis, iontophoresis, electrical stimulation, or therapeutic laser therapy to treat patellofemoral pain.

Evidence suggests that patient education regarding plan of care, patellofemoral joint loading and Kinesio phobia helps to improve exercise program compliance to a rehabilitation exercise program.  The evidence suggests that a multimodal approach is ideal in the treatment of patellofemoral pain but that exercise is the primary factor in successful treatment.

Discussion and clinical utility:

This CPG is helpful because it provides new classifications of patellofemoral pain to help clinicians guide their plans of care.  It is also useful to see that exercise is the biggest factor in the effective treatment of patellofemoral pain.  This helps clinicians empower patients to be active and help treat their own symptoms.

References:

Willy RW, Hoglund LT, Barton CJ, Bolgla LA, Scalzitti DA, Logerstedt DS, Lynch AD, Snyder-Mackler L, McDonough CM. Patellofemoral Pain. J Orthop Sports Phys Ther. 2019 Sep;49(9):CPG1-CPG95. doi: 10.2519/jospt.2019.0302. PMID: 31475628.

Reviewed by Tyler Tice, PT, DPT, OCS, ATC

Article: 

Physical Therapy Management of Neurogenic Thoracic Outlet Syndrome.

Introduction: 

Neurogenic thoracic outlet syndrome is a difficult condition to treat for many reasons.  The region is complex, including multiple joints, the brachial plexus and the subclavian artery.  The diagnosis of neurogenic thoracic outlet syndrome is still considered a diagnosis of exclusion, and there are often other regions involved such as cervical or thoracic spine dysfunctions that can make it difficult to identify the cause or causes of the problem.

There have been many treatment theories presented that can include postural training to improve diaphragm function, scalene and pectoralis minor releases to open space for the neurovascular bundle, shoulder girdle strengthening to decrease fatigue of the muscles in the region and scapulohumeral rhythm training to improve overall mechanics of motion in the region.  Despite the challenges of physical therapy to treat this condition, it is still recommended before attempting surgical intervention.  In one observational study, as many as 27% of patients receiving physical therapy met their goals without needing to progress to surgical intervention.

Methods:

This article discusses different aspects of treating neurogenic thoracic outlet syndrome such as interviewing, different treatment approaches, assessment techniques, support for patients and psychologically informed care.

Results:

  When interviewing a patient with suspected thoracic outlet syndrome, it is important to pay close attention to provoking and relieving activities as well as specific symptoms as these can be clues to whether the symptoms are caused by aggravated vascular tissue or aggravated nervous tissue.  For example, vascular thoracic outlet syndrome can sometimes present with claudication-like symptoms while neurogenic usually does not.  Some patients may be more sensitive to activities that stretch the neurovascular bundle while others may be more sensitive to activities that compress it.  Understanding this information is essential to recommending exercises and activity modification that can help relieve a patient’s symptoms.  Patient reported outcome measures can be useful for gathering this information.

A detailed physical assessment is necessary to rule out other more common pathologies such as cervical radiculopathy which can present with similar findings.  Since the proposed pathoanatomical cause of thoracic outlet syndrome is compromise of the neurovascular bundle, postural and biomechanical screening is key in understanding what patterns or postures may be contributing to this possible compromise.  To get a clear picture of a patient’s presentation, a biomechanical and postural screen should include but is not limited to cervical motion, thoracic motion and scapulohumeral rhythm.

Functional assessment and reassessment can be a useful tool for creating a plan of care as well as helping patients understand what might be triggering their symptoms.  The author uses upper extremity elevation as an example.  While a patient is raising their arm, the therapist can provide a variety of manual cues or resistance to alter the movement pattern and reassess for symptoms.  This could involve shifting the entire shoulder girdle, retracting the cervical spine or facilitating scapular upward rotation.

For treatment, it is important to keep in mind that the goal is often to change the forces moving through the thoracic outlet region.  Bearing in mind that some patients are irritated by traction and others can be irritated by compression, the therapist must be mindful of what positions they want to train in while continually monitoring the patient’s response.  Manual therapy to the scalenes, pectoralis minor, lower cervical and upper thoracic spine can be beneficial to decrease forces across the region and to modulate pain levels.

Although the goal of therapy is active management of the thoracic outlet region via muscular control, passive modalities such as taping can be used during the initial stages of treatment to help patients manage their pain and decrease their tissues irritability levels so they can respond more favorably to other interventions such as scapular stability training.

Stretching of specific muscles found during physical examination such as the scalenes and pectoralis minor should be done with caution.  Although the shortened length of these muscles may be a contributing factor in thoracic outlet syndrome, performing stretches can increase pressure on the neurovascular bundle, exacerbating symptoms.  Instead, the author recommends lengthening these muscles with manual interventions while the core and neck are relaxed and supported in the supine position.  In this way, there is little to no increased pressure on the neurovascular bundle, but a similar effect can be obtained.

Once a more optimal posture is identified for a patient and they are comfortable in this new position, the course of treatment should shift focus toward building endurance in this new position to help maintain the positive changes discovered during therapy.  Additionally, to get carryover into a patient’s everyday life it is necessary to assess and modify the ergonomics of their work and home environments to prevent future exacerbations.

Although positive neural tension testing is often observed with thoracic outlet syndrome, the author cautions against the use of neural gliding or flossing techniques, as these can increase a patient’s tissue irritability rather than decreasing it.  The author instead suggests exercise that focuses on thoracic flexion and rotation to get a more favorable outcome.

During an episode of care, it is important to bear a patient’s emotional state in mind.  It has been shown that motivational interviewing can be an effective adjunct therapy to help manage a patient’s pain.  The physical therapist is in a unique position to help encourage a more active lifestyle for patients as well as to reinforce helpful though patterns that can help patients reframe their pain to help them manage more effectively.

Discussion/Clinical Utility:

  This article provides a basic framework for both assessing and treating neurogenic thoracic outlet syndrome.  Given that thoracic outlet syndrome is considered a diagnosis of exclusion, it is helpful to have some sort of guideline for assessment and treatment planning.  This article does a good job of demonstrating the nuance of the condition by explaining not just what treatments might be appropriate but also the rationale of when you may choose one treatment over another.

Reference:

Collins E, Orpin M. Physical Therapy Management of Neurogenic Thoracic Outlet Syndrome. Thorac Surg Clin. 2021 Feb;31(1):61-69. doi: 10.1016/j.thorsurg.2020.09.003. PMID: 33220772.