About

Deepak Kumar, PT, PhD, is an Associate Professor in the Department of Physical Therapy at Boston University Sargent College of Health & Rehabilitation Sciences. He holds additional titles as an Assistant Professor at the BU School of Medicine and serves as the Director of the Movement & Applied Imaging Lab. His educational background includes a B.Sc. (Hon) from Delhi University in India, a Master of Physiotherapy from Jamia Hamdard in New Delhi, and a PhD from the University of Delaware. He also completed a postdoctoral fellowship at the University of California, San Francisco. His research focuses on human movement analysis, utilizing technologies such as motion capture, force platforms, instrumented treadmills, surface electromyography, inertial and wearable sensors, gait analysis systems, musculoskeletal modeling, dual fluoroscopy, and MR imaging. Dr. Kumar teaches courses related to instrumentation for motion analysis and doctoral seminars in rehabilitation sciences, emphasizing research skills, ethical considerations, and interdisciplinary approaches in rehabilitation sciences. His work aims to advance understanding and application of human movement analysis in clinical and research settings.

Research topics

• Physical therapy
• Medicine
• Physical medicine and rehabilitation
• Internal medicine
• Political Science
• Intensive care medicine
• Art
• Literature
• Psychiatry
• Pathology
• Surgery

Selected publications

• Prefrontal cortex activation during daily movements and its association with clinical symptoms in knee osteoarthritis

  Osteoarthritis and Cartilage Open · 2025-04-24 · 1 citations

  articleOpen accessSenior author

  <h2>Abstract</h2><h3>Objective</h3> For people with knee osteoarthritis (OA), step-up is one of the most physically demanding and pain-evoking daily movements. Given the significant role of the prefrontal cortex (PFC) in executive function and pain modulation, our objectives were (1) to assess PFC activation during walking and step-up in people with knee OA and (2) to examine the association of pain and psychological outcomes with changes in PFC activation from walking to step-up. <h3>Design</h3> This cross-sectional study included 44 individuals with symptomatic knee OA. Participants completed Knee Injury and Osteoarthritis Outcome Score (KOOS), Pain, Enjoyment of Life, and General Activity (PEG) scale, Patient Health Questionnaire (PHQ-8) for mood, 3-item Pain Catastrophizing Scale (PCS), and Fear-Avoidance Beliefs Questionnaire (FABQ). Oxygenated hemoglobin concentration changes (HbO₂) in the bilateral PFC were assessed using functional Near-Infrared Spectroscopy. HbO₂ were compared between tasks using repeated measures ANCOVA. Multiple linear regression models tested the association between clinical outcomes and changes in HbO₂ from walking to step-up while adjusting for confounders. <h3>Results</h3> HbO₂ during step-up was higher compared to walking, with moderate effect size (<i>d</i> ​= ​0.3–0.5). Greater pain catastrophizing (R² ​= ​0.10) was correlated with smaller changes in HbO₂ from walking to step-up. <h3>Conclusion</h3> People with knee OA utilized greater executive control during step-up compared to walking. Similar to stair climbing, step-up is more physically demanding and more frequently impaired than walking. Greater pain catastrophizing was related to smaller increases in PFC activation from walking to step-up, reflecting the availability of fewer executive resources to maintain task performance.

  PublisherOA PDFDOI

• DAILY LIFE WALKING AND WORSENING KNEE PAIN OVER 2 YEARS: THE MULTICENTER OSTEOARTHRITIS STUDY

  Osteoarthritis and Cartilage · 2025-05-30

  article1st authorCorresponding
  PublisherDOI

• Prefrontal cortex function and gait alterations during single- and dual-task walking in knee osteoarthritis

  PLoS ONE · 2025-09-11 · 1 citations

  articleOpen accessSenior authorCorresponding

  Over-recruitment of the prefrontal cortex (PFC) during complex walking conditions may reflect altered motor and cognitive performance in people with knee osteoarthritis (OA). Our objectives were (1) to assess PFC activation, and motor and cognitive performance, during single- and dual-task walking in people with knee OA and (2) to examine the association of PFC activation with the performance. Forty-eight people with symptomatic knee OA completed three tasks, (1) single-task walking (STW) (2) subtraction by 7 from a 3-digit number (S7), and (3) dual-task walking (DTW), a combination of STW and S7. Oxygenated hemoglobin concentration changes (ΔHbO2) in bilateral prefrontal cortex (PFC) were assessed using functional Near-Infrared Spectroscopy. Motor performance outcomes included gait speed, step duration variability, and stride length variability. Cognitive performance was assessed as the correct response rate during S7. We used repeated measures ANCOVA to compare the outcomes by tasks. Correlation and multiple linear regression analyses were used to determine the association between PFC activation and performance outcomes. PFC activation was higher during STW and DTW compared to S7 but not significantly different between STW and DTW. People with knee OA walked slower (d = 0.63) and had higher variability in step duration (d = 0.45) and stride length (d = 0.37) during DTW compared to STW. Greater activation in right ventrolateral PFC (R2 = 0.15) and left dorsomedial PFC (R2 = 0.12) were associated with lower step duration variability. When walking is challenged with a cognitive task, people with knee OA show deterioration of gait performance and no change in PFC activation.

  PublisherDOI

• Participant Experiences in Using a Telehealth Mindful Exercise Program for Knee Osteoarthritis: A Qualitative Study

  Journal of Integrative and Complementary Medicine · 2025-10-01 · 1 citations

  articleSenior author

  Objective: To explore the acceptability of an 8-week, telehealth, group-based, mindful exercise intervention in individuals with knee osteoarthritis (OA). Methods: This qualitative study was nested within a randomized controlled trial ( N = 40) comparing a mindful exercise intervention to an exercise-only control group. Thirteen participants from the mindful exercise arm were individually interviewed remotely using HIPAA-compliant Zoom. Interviews were guided by the Theoretical Framework of Acceptability (TFA). The transcripts were analyzed using an inductive thematic approach, and the identified themes were mapped onto TFA constructs to determine factors related to the intervention’s acceptability. Results: Eight key themes were identified as follows: (1) Openness to Alternative Treatments for Knee Pain, (2) Challenges with Exercise and Equipment, (3) Varied Perceptions of Mindfulness, (4) Mindfulness was Enjoyable but Challenging, (5) Integration of Mindfulness with Exercise Varied by Exercise Type, (6) Perceived Impact of Intervention was Physical and Psychological, (7) Group Telehealth Format Enhanced Intervention Acceptability, and (8) 2-H Time Commitment was Challenging. Mapping these themes onto the constructs of the TFA highlighted factors that influenced the acceptability of the mindful exercise intervention. These included enjoyment in practicing mindfulness especially when integrated with familiar exercises, the 8-week intervention length, and convenience of the group and telehealth aspects of the intervention. Participants encountered challenges with the 2-h weekly time, exercise equipment, learning and practicing mindfulness independently, and absence of alternative formats (e.g., hybrid or self-guided options). Conclusion: The mindful exercise intervention was generally acceptable to people with knee OA. However, to enhance acceptability, modifications may be needed, such as adjusting the exercise types and equipment, providing additional support for learning and practicing mindfulness, and offering greater flexibility in session format, timing, and duration. These insights are valuable for developing more effective, patient-centered, mindfulness-based exercise interventions for individuals with knee OA.

  PublisherDOI

• AGREEMENT BETWEEN MARKER-BASED AND MARKERLESS MOTION CAPTURE FOR ASSESSMENT OF KINEMATICS AND KINETICS DURING FUNCTIONAL ACTIVITIES IN PEOPLE WITH KNEE OSTEOARTHRITIS

  Osteoarthritis and Cartilage · 2025-04-01

  articleSenior author
  PublisherDOI

• Association of central pain sensitization with prefrontal cortex activation during single- and dual-task walking in knee osteoarthritis

  Osteoarthritis and Cartilage · 2025-04-01

  articleSenior author
  PublisherDOI

• Relation of pain sensitization to knee loading during walking in people with knee osteoarthritis

  Osteoarthritis and Cartilage · 2025-02-04 · 5 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Relation of vertical ground reaction forces while walking to contralateral structural worsening in adults with unilateral knee osteoarthritis: the Multicenter Osteoarthritis Study

  Clinical Biomechanics · 2025-11-22

  articleOpen access
  PublisherOA PDFDOI

• Association of Physical Therapy Care With Use of Intra‐Articular Injections in People With Knee Osteoarthritis: A Real‐World Cohort Study

  Arthritis & Rheumatology · 2025-03-17 · 2 citations

  articleOpen accessSenior authorCorresponding

  OBJECTIVE: The objective of this study was to assess the relation of physical therapy (PT) timing, dose, and type with risk of future intra-articular therapy use in people with knee osteoarthritis (OA) who receive PT. METHODS: We used data from a deidentified claims database (Optum Labs Data Warehouse) from American adults with incident knee OA referred for PT within the first year of their knee OA diagnosis. We categorized people as having previously had intra-articular therapies or not. We examined the association of timing of PT initiation, number of PT sessions, and type of PT (predominantly active or passive) with intra-articular therapy use over a period of one year following the first year of diagnosis. RESULTS: Of the 67,245 individuals with knee OA (age 61.5 ± 11 years, 61% female, 10% Black, 6% Hispanic), 34,804 and 32,441 did and did not have prior intra-articular therapies, respectively. Among those who had prior intra-articular therapies, initiating PT at 9 to 12 months post diagnosis was associated with an adjusted risk ratio of 1.44 for future intra-articular therapy (95% confidence interval 1.35-1.55) compared with those who initiated within a month. For both groups, ≥13 PT sessions was associated with a 10% and 12% lower risk, respectively, compared with 1 to 5 sessions. Active PT was not related to lower risk compared to passive PT interventions. CONCLUSION: Initiating PT earlier and more than 12 PT sessions were significantly associated with lower risk of future intra-articular therapy use in people with newly diagnosed knee OA.

  PublisherOA PDFDOI

• GREATER MUSCLE ACTIVATION DURING STEP-UP IS RELATED WITH LOWER PAIN DURING MOVEMENT AND BETTER PHYSICAL FUNCTION IN PEOPLE WITH KNEE OSTEOARTHRITIS

  Osteoarthritis and Cartilage · 2025-04-01

  articleSenior author
  PublisherDOI

Recent grants

• Mind Your Walk Intervention for Community-Based Management of Knee OA: A Feasibility Study

  NIH · $676k · 2017–2022

Frequent coauthors

• Richard B. Souza

  American Physical Therapy Association

  67 shared

• Malik Qistas Ahmad

  University of Pittsburgh Medical Center

  49 shared

• Abdul Wahab Arif

  St. Joseph’s University Medical Center

  49 shared

• Muhammad Bilal Malik

  Quaid-i-Azam University

  49 shared

• Chandur Bhan

  Saint Joseph Hospital

  49 shared

• Ali Asad

  University Hospitals Coventry and Warwickshire NHS Trust

  49 shared

• Zohaib Sayyed

  Shaikh Zayed Postgraduate Medical Institute

  49 shared

• Khawaja Hassan Akhtar

  University of Oklahoma Health Sciences Center

  49 shared

Labs

• Movement & Applied Imaging LabPI