Mentoring Minutes: Knee Osteoarthritis


Knee Joint Contact Mechanics during Downhill Gait and its Relationship with Varus/Valgus Motion and Muscle Strength in Patients with Knee Osteoarthritis

Shawn Farrokhi, PT, Ph.D., DPT,1 Carrie A. Voycheck, Ph.D.,2 Jonathan A. Gustafson, B.S.,3 G. Kelley Fitzgerald, PT, Ph.D.,4 and  Scott Tashman, Ph.D.5

- The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA).

- patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p<0.01) and greater quadriceps and hip abductor muscle weakness

Clin Biomech (Bristol, Avon). 2011 Aug; 26(7): 741–748. 

Published online 2011 Apr 21. doi:  10.1016/j.clinbiomech.2011.03.006

Effects of Progressive Resistance Strength Training on Knee Biomechanics During Single Leg Step-up in Persons with Mild Knee Osteoarthritis

Kevin James McQuade, PhD and  Anamaria Siriani de Oliveira, PhD

- Subjects participated in an individually supervised training program 3 times a week for eight weeks consisting of progressive resistive exercises for knee extensors and knee flexors. Pre and post training outcome assessments included: 1. Net internal knee joint moments, 2. Electromyography of primary knee extensors and flexors, and 3. Self-report measures of knee pain and function. The distribution of lower extremity joint moments as a percent of the total support moment was also investigated.

- Pain, symptoms, activities of daily life, quality of life, stiffness, and function scores showed significant improvement following strength training. Knee internal valgus and hip internal rotation moments showed increasing but non-statistically significant changes post-training. There were no significant differences in muscle co-contraction activation of the Quadriceps and Hamstrings.

BMC Musculoskelet Disord. 2013; 14: 266. Published online 2013 Sep 12. doi:  10.1186/1471-2474-14-266

Efficacy of strength and aerobic exercise on patient-reported outcomes and structural changes in patients with knee osteoarthritis: study protocol for a randomized controlled trial

Britt Elin Øiestad,1 Nina Østerås,2 Richard Frobell,3 Margreth Grotle,4 Helga Brøgger,5 and May Arna Risberg1,6

- strength training: 2-3x aweek, 12 weeks; 3 sets of 8-10 reps, 30 -60 sec rest breaks; 5 min warm up on bike

- first 2 weeks, focused on neuromuscular exercise with low intensity

- Quadriceps and hamstrings, hip abductors and extensors, and calf muscles.

- load increased when able to do 2 more reps

-Aerobic: main aim of the aerobic exercise is to improve cartilage quality, in addition to the general health effects physical activity gives. Both overloading and underloading may cause cartilage degradation, but moderate loading has been shown to be beneficial for joint health because of mechanosensitive chondroprotective pathways. Based on the moderate loading benefits, ergometer cycling for 45 minutes 2–3 times a week, including 10 minutes warm up, 30 minutes on moderate loading (75% of max heart rate) and 5 minutes cool down will be required. For instance, a patient with a maximal heart rate of 160 and rest heart rate of 60 will be required to cycle at a heart rate of about 135 using the formula for heart rate reserve (160-rest heart rate of 60 × 0.75 + rest heart rate of 60).


J Orthop Res. 2013 Jul;31(7):1020-5. doi: 10.1002/jor.22340. Epub  2013 Mar 12.

Six-week gait retraining program reduces knee adduction moment, reduces pain, and improves function for individuals with medial compartment knee osteoarthritis.

Shull PB1, Silder AShultz RDragoo JLBesier TFDelp SLCutkosky MR.

- 6-week gait retraining program on the knee adduction moment (KAM) and knee pain and function. subjects with medial compartment knee osteoarthritis and self-reported knee pain –

- WOMAC scores and a 10-point visual-analog pain scale score were measured at baseline, post-training (end of 6 weeks), and 1 month after training ended.

- Gait retraining reduced the first peak KAM by 20% post-training as a result of a 7° decrease in foot progression angle (i.e., increased internal foot rotation), compared to baseline

- WOMAC pain and function scores were improved at post-training by 29% and 32%, pain scale scores improved by two . Changes in WOMAC pain and function were approximately 75% larger than the expected placebo effect. Changes in KAM, foot progression angle, WOMAC pain and function, and visual-analog pain score were retained 1 month after the end of the 6-week training.


J Biomech. 2013 Jan 4;46(1):122-8. doi: 10.1016/j.jbiomech.2012.10.019. Epub 2012 Nov 10.

Toe-in gait reduces the first peak knee adduction moment in patients with medial compartment knee osteoarthritis.

Shull PB1, Shultz RSilder ADragoo JLBesier TFCutkosky MRDelp SL.

- The first peak of the knee adduction moment has been linked to the presence, severity, and progression of medial compartment kneeosteoarthritis. The objective of this study was to evaluate toe-in gait (decreased foot progression angle from baseline through internal foot rotation) as a means to reduce the first peak of the knee adduction moment in subjects with medial compartment knee osteoarthritis. Additionally, we examined whether the first peak in the knee adduction moment would cause a concomitant increase in the peak external knee flexion moment, which can eliminate reductions in the medial compartment force that result from lowering the knee adduction moment. We tested the following hypotheses: (a) toe-in gait reduces the first peak of the knee adduction moment, and (b) toe-in gait does not increase the peak external knee flexion moment. Twelve patients with medial compartment knee osteoarthritis first performed baseline walking trials and then toe-in gait trials at their self-selected speed on an instrumented treadmill in a motion capture laboratory. Subjects altered their foot progression angle from baseline to toe-in gait by an average of 5° (p<0.01), which reduced the first peak of the knee adduction moment by an average of 13% (p<0.01). Toe-in gait did not increase the peak external knee flexion moment (p=0.85). The reduced knee adduction moment was accompanied by a medially-shifted knee joint center and a laterally-shifted center of pressure during early stance. These results suggest that toe-in gait may be a promising non-surgical treatment for patients with medial compartment knee osteoarthritis.

J Orthop Sports Phys Ther. 2010 Jun;40(6):A1-A35. doi: 10.2519/jospt.2010.0304.

Knee pain and mobility impairments: meniscal and articular cartilage lesions.

Logerstedt DSSnyder-Mackler LRitter RCAxe MJOrthopedic Section of the American Physical Therapy Association.

J Man Manip Ther. 2010 Mar;18(1):29-36. doi: 10.1179/106698110X12595770849560.

The effect of tibio-femoral traction mobilization on passive knee flexion motion impairment and pain: a case series.

Maher S1, Creighton DKondratek MKrauss JQu X.

- The purpose of this case series was to explore the effects of tibio-femoral (TF) manual traction on pain and passive range of motion (PROM) in individuals with unilateral motion impairment and pain in knee flexion. Thirteen participants volunteered for the study. All participants received 6 minutes of TF traction mobilization applied at end-range passive knee flexion. PROM measurements were taken before the intervention and after 2, 4, and 6 minutes of TF joint traction. Pain was measured using a visual analog scale with the TF jointat rest, at end-range passive knee flexion, during the application of joint traction, and immediately post-treatment. There were significant differences in PROM after 2 and 4 minutes of traction, with no significance noted after 4 minutes. A significant change in knee flexion of 25.9°, which exceeded the MDC(95,) was found when comparing PROM measurements pre- to final intervention. While pain did not change significantly over time, pain levels did change significantly during each treatment session. Pain significantly increased when the participant's knee was passively flexed to end range; it was reduced, although not significantly, during traction mobilization; and it significantly decreased following traction. This case series supports TF joint traction as a means of stretching shortened articular and periarticular tissues without increasing reported levels of pain during or after treatment. In addition, this is the first study documenting the temporal aspects of treatment effectiveness in motion restoration.