Boston Sports Medicine and Performance Group, LLC Blog

Up the Chain it Goes...

Posted by Boston Sports Medicine and Performance Group on Sun, Apr 29, 2012 @ 15:04 PM

By Art Horne



derrick rose torn acl



With recent season ending ACL injuries to New York Knicks Iman Shumpert, and Chicago Bull’s point guard Derrick Rose coming on the same day, (not to mention Eric Maynor from the Thunder and Spanish Star Ricky Rubio earlier this season) discussion has arisen as to how these terrible injuries could have been avoided.  Although the possible contributing factors are endless, ranging from previous injury to simply fatigue, one area worth shedding more light on, especially in the case of young Rose, is the implication of the kinetic chain as a whole.

Let’s start at the ground and work our way up.

I think we’d all agree that the big toe is a big deal.   But how closely are we looking at this “pivotal” body-ground juncture?

In a study by Munuera et al, researchers found that “Hallux interphalangeal joint dorsiflexion was greater in feet with hallux limitus than in normal feet.  There was a strong inverse correlation between first metatarsophalangeal joint dorsiflexion and hallux interphalangeal joint dorsiflexion.” (Munuera et al, 2012). 

TRANSLATION: People with abnormally stiff or limited motion at the great toe had excessive motion at the joint just distal.

If you don’t have mobility where you need it, you’ll surely get it somewhere else.

Let’s move up the chain shall we?

In a study by Van Gheluwe and his group,  researchers looked at how a stiff or limited great toe joint changes the way we walk.  In their study, “two populations of 19 subjects each, one with hallux limitus and the other free of functional abnormalities, were asked to walk at their preferred speed while plantar foot pressures were recorded along with three-dimensional foot kinematics.  The presence of hallux limitus, structural or functional, caused peak plantar pressure under the hallux to build up significantly more and at a faster rate than under the first metatarsal head.  Additional discriminators for hallux limitus were peak dorsiflexion of the first metatarsophalangeal joint, time to this peak value, peak pressure ratios of the first metatarsal head and the more lateral metatarsal heads, and time to maximal pressure under the fourth and fifth metatarsal heads.  Finally, in approximately 20% of the subjects, with and without hallux limitus, midtarsal pronation occurred after heel lift, validating the claim that retrograde midtarsal pronation does occur.”

TRANSLATION: if you have a limited motion in your great toe, pressure changes will occur – increase pressure changes will cause pain over time (think blister on your foot).

And pain changes the way we move – period.

Let’s take a look at the ankle.

In an article  by Denegar et al, the authors outline the importance of regaining normal talocrural joint arthrokinematics following an ankle injury.   The authors note,

 “All of the athletes we studied had completed a rehabilitation program as directed by their physician under the supervision of a certified athletic trainer, and had returned to sports participation.  Furthermore, all had performed some form of heel-cord stretching. None, however, had received joint mobilization of the talocrural complex.  Despite the return to sports and evidence of restoration in dorsiflexion range of motion, there was restriction of posterior talar mobility in most of the injured ankles.  Posterior talar mobilization shortens the time required to restore dorsiflexion range and a normal gait.  Without proper talar mobilization, dorsiflexion range of motion may be restored through excessive stretching of the plantar flexors, excessive motion at surrounding joints, or forced to occur through an abnormal axis of rotation at the talocrural joint.” (pg. 172)

TRANSLATION: I repeat, Without proper talar mobilization, dorsiflexion range of motion may be restored through excessive stretching of the plantar flexors, excessive motion at surrounding joints, or forced to occur through an abnormal axis of rotation at the talocrural joint.” (pg. 172)

If you don’t have normal ankle motion, and specifically at the talus, your ankle motion (although appearing normal) is probably coming from other joints and/or in a combination with foot pronation.


Foot Pronation = Tibial Internal Rotation

Tibial Internal Rotation = Femoral Internal Rotation

Tibia and Femur Internal Rotation  =  Knee Valgus (or knee collapse)

Knee Valgus = BAD


But just because you have some extra motion doesn’t mean you’re doomed right?


But, excessive motion without the ability to control that motion certainly does.  So where does knee control come from? The Hip!

But hip strength, control, and neuromuscular timing is seldom appreciated, and in the case of the basketball athlete it is certainly poorly measured, especially after ankle injury.

In a study by Bullock-Saxton, researchers investigated muscle activation during hip extension after ankle sprain and showed a changes in timing of muscle activation in the ankle sprain grouped compared to the non-injured group.

 “the results highlight the importance of the clinician’s paying attention to function of muscles around the joints separated from the site of injury.  Significant delay of entry of the gluteus maximus muscle into the hip extension pattern is of special concern, as it has been proposed by Janda that the early activation of this muscle provides appropriate stability to the pelvis in such functional activities as gait.” (pg. 333)


In another study examining ipsilateral hip strength/weakness after the classic ankle sprain, researchers demonstrated that subjects with unilateral chronic ankle sprains had weaker hip abduction strength and less plantar flexion range of motion on the involved sides (Friel et al., 2006)

“Our findings of weaker hip abductors in the involved limb of people with chronic ankle sprains supports this view of a potential chronic loss of stability throughout the kinetic chain or compensations by the involved limb, thus contributing to repeat injury at the ankle.” (pg. 76)

“If the firing, recruitment, and strength of the hip abductor muscles in people with ankle sprains have been altered because of the distal injury, the frontal-plane stability normally supplied by this muscle is lacking, and the risk for repeat injury increases.  Weak hip abductors are unable to counteract the lateral sway, and an injury to the ankle may ensue.”

TRANSLATION: Ankle sprains cause neuromuscular changes up the chain and specifically in the hip.  If this weakness is not addressed after an ankle injury,” frontal-plane stability normally supplied by this muscle is lacking.” 


Lack of frontal-plane stability + Knee Valgus = Injury


Of course suggesting that the above points are exactly the reason for which Rose suffered his injury is certainly a stretch and not the intention of this post, nor is it to question the treatment that he or any other NBA player received prior to their devastating injury (for the record, the Chicago Bulls Sports Medicine and Strength Staff are regarded as one of the very best in the league).  What I am suggesting however is that examining athletes and patients with the use of advanced technology to determine a state of readiness to participate, and/or examine more closely changes in gait and neuromuscular firing is certainly worth pursuing, especially in light of the ever-rising salaries within professional sports.  A quick look is certainly worth the small investment.

One thing is for sure, ACL injury is not limited to teenage females or only seen on the soccer pitch.


Previous Posts:

The NBA Should Have Learned From The NFL - Injuries On The Rise

Did The NBA Lock-out Ultimately End Chauncey Billups' Career?


See lectures directly related to gait, injury prevention, and performance at the 2012 BSMPG Summer Seminar:

1. Dr. Bruce Williams: Hit the ground running: Appreciating the importance of foot strike in NBA injuries

2. Dr. Bruce Williams: Breakout Session: Restoring Gait with evidence based medicine

3. Art Horne and Dr. Pete Viteritti: Improving Health & Performance - Restoring ankle dorsiflexion utilizing a manual therapy approach

4. Dr. Tim Morgan: Biomechanics and Theories of Human Gait: Therpeutic and Training Considerations

5. Jose Fernandez: Advanced Player Monitoring for Injury Reduction



See the most advanced player monitoring equipment currently available at the 2012 BSMPG Summer Seminar:


 zeo affectiva  ithlete

BioSensics  Zflo insideTracker


Dartfish  freelap timing   Tekscanoptosource

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Munuera PV, Trujillo P, Guiza L, Guiza I. Hallux Interphalangeal Joint Range of Motion in Feet with and Without Limited First Metatarsophalangeal Joint Dorsiflexion. J Am Podiatr Med Assoc. 102(1): 47-53, 2012.

Denegar, C., Hertel, J., Fonesca, J.  The Effect of Lateral Ankle Sprain on Dorsiflexion Range of Motion, Posterior Talar Glide, and Joint Laxity.  J Orthop Sports Phys Ther. 2002; 32(4):166-173.


Van Gheluwe B, Dananberg HJ, Hagman F, Vanstaen K. Effects of Hallux Limitus on Plantar Foot Pressure and Foot Kinematics During Walking. J Am Podiatr Med Assoc. 96(5): 428-436, 2006.

Bullock-Saxton, J. E., Janda, V., & Bullock, M. I. (1994) The Influence of Ankle Sprain Injury on Muscle
Activation during Hip Extension. Int. J. Sports Med. Vol. 15 No. 6, 330-334.

Friel, K., McLean, N., Myers, C., & Caceres, M. (2006). Ipsilateral Hip Abductor Weakness After Inversion
Ankle Sprain. Journal of Athletic Training. Vol. 41 No.1, 74-78

Smith RW, Reischl SF. Treatment of ankle sprains in young athletes. Am J Sports Med. 1986;14:465-471.

Topics: Art Horne, basketball performance, basketball training programs, BSMPG, athletic training conference, Charlie Weingroff, boston hockey conference, barefoot strength training, Andrea Hudy, Bruce Williams, Cal Dietz, Alan Grodin, Barefoot in Boston, Dr. DiMuro, Dan Boothby, Chris Powers, achilles pain, Dorsiflexion, ankle problems

Meet Chris Powers - 2012 BSMPG Summer Seminar Keynote Speaker

Posted by Boston Sports Medicine and Performance Group on Sat, Apr 28, 2012 @ 08:04 AM


Over the last decade no one has changed the way we approach and treat knee pain more than Chris Powers.  

Learn how the Hip is a major factor when it comes to the aches and pains associated with your knee at the 2012 BSMPG Summer Seminar!


Chris Powers 

Topic: Proximal Factors Contributing to Running Injuries


Christopher M. Powers is an Associate Professor in the Division of Biokinesiology & Physical Therapy, and Co-Director of the MBRL at USC. He also has joint appointments in the Departments of Radiology and Orthopaedic Surgery within the Keck School of Medicine.  His primary teaching responsibilities include the areas of biomechanics and the mechanics of human gait. He received a Bachelors degree in Physical Education from the University of California, Santa Barbara in 1984, his Masters degree in Physical Therapy from Columbia University in 1987, and a Ph.D. in Biokinesiology in 1996 from USC. Dr. Powers did his post-doctoral training at the Orthopaedic Biomechanics Laboratory, University of California, Irvine.

Dr. Powers studies the biomechanical aspects of human movement. More specifically, his research and publications are concerned with the kinematic, kinetic and muscular actions associated with human movement, the pathomechanics of orthopedic disabilities and issues related to rehabilitation of the musculoskeletal system. He has published over 90 peer-reviewed articles and has received several research awards from the American Physical Therapy Association, including the Rose Excellence in Research Award from the Orthopaedic Section, the Eugene Michels New Investigator Award, the Dorothy Briggs Scientific Inquiry Award and the Helen J Hislop Award for contributions to the professional literature.

Dr. Powers is a Fellow of the American College of Sports Medicine and a member of the American Physical Therapy Association (Orthopaedic and Research sections), American Society for Biomechanics, American Society for Testing and Measures, and the North American Society for Gait and Clinical Movement Analysis. In addition, Dr. Powers is on several editorial boards including the Journal of Applied BiomechanicsJournal of Orthopaedic and Sports Physical Therapy, and the Journal of Athletic Training.  He is an active member of the American Physical Therapy Association, serving as President of the Section on Research.



  • Postdoctoral Fellow, Orthopaedic Biomechanics (1996-1997), University of California, Irvine, CA
  • Ph.D. Biokinesiology (1996). University of Southern California, Los Angeles, CA
  • M.S. Physical Therapy (1987). Columbia University, New York, NY
  • B.A. Physical Education (1984). University of California, Santa Barbara, Santa Barbara, CA

Selected Publications

  • Stefanik JJ, Zhu Y, Zumwalt AC, Gross KD, Clancy M, Lynch JA, Frey LA, Lewis CE, Roemer FW,Powers CM, Guermazi A, Felson DT. The association between patella alta and the prevalence and worsening of structural features of patellofemoral joint osteoarthritis: The Multicenter Osteoarthritics Study. Arthritis Care & Res (In press).
  • Farrohki S, Colletti PM, Powers CM. Differences in patella cartilage thickness, T2 relaxation time and cartilage deformational behavior: A comparison of young females with and without patellofemoral pain. Am J Sports Med (In press).
  • Chen YJ, Scher I, Powers CM. Quantification of patellofemoral joint reaction forces during functional tasks: A subject specific, three dimensional model. J Appl Biomech (In press).
  • Kulig K, Harper-Hanigan K, Souza RB, Powers CM. Measurement of femoral torsion by ultrasound and magnetic resonance imaging: Concurrent validity. Phys Ther (In pre).
  • Souza RB, Draper CE, Fredericson M, Powers CM. Femur rotation and patellofemoral joint kinematics: A weight-bearing MRI analysis. J Orthop Sports Phys Ther. 40:277-285, 2010.
  • Powers CM, Chen YJ, Scher I, Lee TQ. Multi-plane loading of the extensor mechanism alters the patellar ligament force/quadriceps force ratio. J Biomed Eng. 132:024503, 2010.
  • Fithian DC, Powers CM, Khan N. Rehabilitation of the knee following medial patellofemoral ligament reconstruction. Clin Sports Med. 29:283-290, 2010.
  • Powers CM, Blanchette MG, Brault JR, Flynn J, Siegmund GP. Validation of walkway tribometers: Establishing a reference standard. Submitted to: J Forensic Sci. 55:366-370, 2010.
  • Powers CM. The influence of abnormal hip mechanics on knee injury: A biomechanical perspective. J Orthop Sports Phys Ther. 40:42-51, 2010.
  • Wagner T, Behnia N, Ancheta WL, Shen R, Farrokhi S, Powers CM. Strengthening and neuromuscular re-education of the gluteus maximus in a triathlete with exercise-association cramping of the hamstrings: A case report. J Orthop Sports Phys Ther. 40:112-119, 2010.
  • Tonley JC, Dye JA, Kochevar RJ, Yun SM, Farrokhi S, Powers CM. Treatment of an individual with piriformis syndrome focusing on hip muscle strengthening and movement re-education: A case report. J Orthop Sports Phys Ther. 40:103-111, 2010.
  • Pollard CD, Sigward SM, Powers CM. Limited hip and knee flexion during landing is associated with increased frontal plane knee motion and moments. Clin Biomech. 25:142-146, 2010.
  • Tsai LC, Sigward SM, Pollard CD, Fletcher MJ, Powers CM. The effects of fatigue and recovery on knee kinetics and kinematics during side-step cutting. Med Sci Sport Exerc. 41:1952-1957, 2009.
  • Kulig K, Beneck GJ, Selkowitz DM, Popovich JM Jr., Ge TT, Flanagan SP, Poppert EM, Yamada K,Powers CM, Azen S, Winstein CJ, Gordon J, Samudrala S, Chen TC, Shamie N, Khoo L, Spoonamore MJ, Wang JC and Physical Therapy Clinical Research Network (PTClinResNet), The effect of an intensive, progressive exercise program on functional performance in patients post single-level lumbar microdiscectomy. Physical Therapy. 89:1145-1157, 2009.
  • Tsai YJ, Powers CM. The influence of footwear sole hardness on utilized coefficient of friction during walking. Gait & Posture. 30:303-306, 2009.
  • Souza RB, Powers CM. Concurrent criterion-related validity and reliability of a clinical test to measure femoral anteversion. J Orthop Sports Phys Ther. 39:586-592, 2009.
  • Souza RB, Powers CM. Predictors of hip rotation during running: An evaluation of hip strength and femoral structure in women with and without patellofemoral pain. Am J Sports Med. 37:579-587, 2009.
  • Souza RB, Powers CM. Differences in hip kinematics, muscle strength and muscle activation between subjects with and without patellofemoral pain. J Orthop Sports Phys Ther. 39:12-19, 2009.
  • Sigward SM. Ota S, Powers CM. Predictors of frontal plane knee excursion during a drop landing in young female athletes. J Orthop Sports Phys Ther. 38:661-667, 2008.
  • Brennglass A, Souza RB, Meyer J, Powers CM. Identification of abnormal hip motion associated with acetabular labral pathology: A resident’s case report. J Orthop Sports Phys Ther. 38:558-565, 2008.
  • Farrokhi S, Pollard CD, Souza R, Chen YJ, Reischl S, Powers CM. Trunk position influences lower extremity demands during the forward lunge exercise. J Orthop Sports Phys Ther. 38:403-409, 2008.
  • Tsai YJ, Powers CM. The influence of footwear sole hardness on slip initiation in young adults. J Forensic Sci. 53:884-888, 2008.
  • Powers CM, Doubleday KL, Escudero C. The influence of patellofemoral bracing on pain, knee extensor torque and gait function in females with patellofemoral pain. Physiother Theory Pract. 24:1-9, 2008.
  • Powers CM, Beneck GJ, Kulig K, Landel RF, Fredericson M. The effects of a single session of posterior to anterior spinal mobilization and press-ups on pain response and lumbar spine extension in persons with nonspecific low back pain. Phys Ther. 88:485-492, 2008.
  • Burke WS, Vangsness CT, Powers CM. Quantification of glenohumeral rhythm in persons with and without impingement. Am J Orthop. 37:24-30, 2008.
  • Landel RF, Kulig KK, Powers CM. Intertester reliability and validity of motion assessments during lumbar spine accessory motion testing. Phys Ther. 88:43-49, 2008.
  • Burnfield JM, Powers CM. The role of center of mass kinematics in predicting utilized coefficient of friction during walking. J Forensic Sci 52:1328-1333, 2007
  • Ward SR, Terk MR, Powers CM. Patella alta: Association with patellofemoral alignment and changes in contact area during weight bearing. J Bone & Joint Surg Am. 89:1749-1755, 2007.
  • Sigward S, Powers CM. Loading characteristics of female athletes who demonstrate excessive valgus moments at the knee during side-step cutting. Clin Biomech. 22:827-833, 2007.
  • Feller JA, Amis AA, Andrish JT, Arendt EA, Erasmus PJ, Powers CM. Surgical biomechanics of the patellofemoral joint. Arthroscopy. 23:542-553, 2007.
  • Pollard CD, Sigward S, Powers CM. Gender differences in hip joint kinematics and kinetics during a side-step cutting maneuver. Clin J Sports Med. 17:38-42, 2007.
  • Powers CM, Stefanou MA, Tsai YJ, Brault JR, Siegmund GP. Assessment of walkway tribometer readings in evaluating slip resistance: A gait based approach. J Forensic Sci. 52:400-405, 2007.
  • Kulig K, Powers CM, Landel R, Chen K, Fredericson M, Guillet M, Butts K. Segmental lumbar mobility in individuals with central low back pain: In-vivo assessment during passive and active motion using dynamic MRI. BMC Musculoskelet Disord. 8:1-10, 2007.
  • Griffin LY, Albohm MJ, Arendt EA, Bahr R, Beynnon BD, DeMaio M, Dick RW, Engebretsen L, Garrett WE, Hannafin JA, Hewitt TE, Huston LJ, Ireland ML, Johnson RJ, Lephart S, Mandelbaum BR, Mann B, Marks RH, Marshal SW, Myklebust G, Noyes FR, Powers CM, Shields C, Schultz SJ, Silvers H, Slauterbeck J, Taylor D, Teitz CC, Wojtys EM, Yu B. Understanding and preventing noncontact anterior cruciate ligament injuries. Am J Sports Med. 34:1512-1532, 2006.
  • Powers CM, Chen YJ, Scher I, Lee TQ. Influence of patellofemoral joint contact geometry on the modeling of three dimensional patellofemoral joint forces. J Biomech. 39:2783-2791, 2006.
  • Selkowitz DM, Kulig K, Poppert EM, Flanagan SP, Mathews Nd, Beneck GJ, Popovich JM, Lona JR, Yamada KA, Burke WS, Ervin C, Powers CM. The immediate and long-term effects of exercise and patient education on physical, functional, and quality of life outcome measures after single-level lumbar microdiscectomy: A randomized controlled trial protocol. BMC Musculoskelet Disord. 7:1-15, 2006.
  • Ota S, Ward SR, Chen YJ, Tsai YJ, Powers CM. Concurrent Criterion-Related validity and reliability of a clinical device used to assess lateral patella displacement. J Orthop Sports Phys Ther. 36:645-652, 2006.
  • Powers CM, Chen YJ, Farrohki S, Lee TQ. The role of peripatellar retinaculum in the transmission of forces within the extensor mechanism. J Bone Joint Surg Am. 88:2042-2048, 2006.
  • Burnfield JM, Powers CM. Prediction of slips: An evaluation of utilized coefficient of friction and available slip resistance. Ergonomics. 49:982-995, 2006.
  • Pollard CD, Sigward SS, Pelley K, Ota S, Powers CM. The influence of an in-season injury prevention program on lower extremity kinematics during landing in young female soccer players. Clin J Sports Med. 16:223-227, 2006.
  • Sigward SM, Powers CM. The influence of experience on knee joint kinematics, kinetics and muscle activation patterns during side-step cutting in young females. Clin Biomech. 21:740-747, 2006.
  • Ganley KJ, Powers CM. Intersegmental dynamics during the swing phase of gait: A comparison of knee kinetics between 7 year old children and adults. Gait Posture. 23:499-504, 2006.
  • Sigward S, Powers CM. The influence of gender on knee joint kinematics, kinetics and muscle activation patterns during side-step cutting. Clin Biomech. 21:41-48, 2006.


Meet Chris Powers, along with Craig Liebenson, Bill Knowles, Coach Schexnayder, and Alan Grodin as they headline the 2012 BSMPG Summer Seminar this May 19-20th in Boston.

This is an event that you don't want to miss!


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Topics: Art Horne, BSMPG, boston hockey summit, Charlie Weingroff, boston hockey conference, Andrea Hudy, Cal Dietz, Bill Knowles, Alan Grodin, Chris Powers