Home > Injury Prevention, Knee Injury, Movement Dysfunction > Decreased Ankle Dorsiflexion Motion Leads to Increased Risk of Patella Tendinopathy

Decreased Ankle Dorsiflexion Motion Leads to Increased Risk of Patella Tendinopathy

Backman LJ, Danielson P.  Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study.  Am J Sports Med. 39(12):2626-2633, 2011.

NOTE:  This article provides strong evidence that restricted ankle dorsiflexion range of motion is a risk factor for the future development of patella tendinopathy in youth basketball athletes.

RATIONALE & PURPOSE: Patellar tendinopathy (PT) is one of the most common reasons for sport-induced pain of the knee.  32% of basketball athletes between 19 and 29 years of age are affected by this condition.  Perhaps more alarming is that 53% of athletes afflicted with PT have reported to end their career due to the condition.  As a result, there is great interest in understanding those factors that may predispose individuals to PT.

The sport of basketball requires a significant amount of ankle dorsiflexion to occur due to the repetitive running, cutting, jumping and landing inherent to the sport.  Full ankle dorsiflexion is needed to assist with properly distributing the kinetic energy during these tasks across the entire kinetic chain.  Failure to achieve adequate ankle dorsiflexion may result in compensatory movement patterns and increased stress across the lower extremity joints and increase the risk for future injury.  Therefore, the purpose of this 1-year prospective study was to analyze if a low ankle dorsiflexion range increases the risk of developing PT for basketball players.

OVERVIEW OF RESEARCH METHODS: A Cohort study design (Level of evidence = 2) was used for this study.  A total of 90 junior elite basketball players (180 knees) were initially examined for different characteristics and potential risk factors for PT, including ankle dorsiflexion range of motion in the dominant and nondominant leg. Baseline ankle dorsiflexion range of motion data were collected at the beginning of the season and athletes were followed over a 1-year period.  Cases of PT were identified over the 1-year follow up period.  Cases of PT met the following criteria: history of activity related anterior knee pain and reduced function, distinct palpation tenderness corresponding to the painful area, and knee pain provoked during a single leg squat.  At the end of the 1-year follow up period all participants underwent re-examination.

KEY FINDINGS: Seventy-five players met the inclusion criteria for participating in the study. At the follow-up, 12 players (16.0%) had developed unilateral PT. These players were found to have had a significantly lower mean ankle dorsiflexion range at baseline than the healthy players, with a mean difference of –4.7° (P = .038) for the dominant limb and –5.1° (P = .024) for the nondominant limb. Complementary statistical analysis showed that players with dorsiflexion range less than 36.5° had a risk of 18.5% to 29.4% of developing PT within a year, as compared with 1.8% to 2.1% for players with dorsiflexion range greater than 36.5°. Limbs with a history of 2 or more ankle sprains had a slightly less mean ankle dorsiflexion range compared to those with 0 or 1 sprain (mean difference, –1.5° to –2.5°), although this was only statistically significant for nondominant legs.

CONCLUSION: This study clearly shows that low ankle dorsiflexion range is a risk factor for developing PT in basketball players. In the studied material, an ankle dorsiflexion range of 36.5° was found to be the most appropriate cutoff point for prognostic screening. This might be useful information in identifying at-risk individuals in basketball teams and enabling preventive actions. A history of ankle sprains might contribute to reduced ankle dorsiflexion range.

CLINICAL APPLICATION:  Sports medicine professionals should be sure to assess ankle dorsiflexion range of motion during pre-season screenings and utilize a corrective exercise strategy to restore normal ankle dorsiflexion motion as part of the individual’s training program.  Also, ankle dorsiflexion motion should be consistently monitored and maintained during training and competition.  Lastly, the article does not differentiate the cause of restricted ankle dorsiflexion range of motion as being either due to soft tissue or arthrokinematic restrictions.  The sports medicine professional should consider the underlying cause of restricted ankle dorsiflexion motion and develop their corrective exercise strategy accordingly.  Joint mobilization techniques may be required if the source is an arthrokinematic restriction.  Static and/or neuromuscular stretching techniques would be appropriate if the source is more soft tissue in nature.
  1. Carl Eaton
    September 21, 2011 at 2:54 pm

    It’s nice to have some confirmation of clinical findings in the research. My question is what is normal DF for a basketball player and is it functionally advantagous (from a power and jumping prospective) to have less DF?

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