Specific and Cross-Over Effects of Foam Rolling on Ankle Dorsiflexion

Self-myofascial release in the form of foam rolling has been found to increase flexibility acutely but how long such increases in range of motion (ROM) last is unclear. Static stretching also increases flexibility acutely and produces a cross-over effect to contralateral limbs.

The cross-over effect or also cross education was already observed in the late 1800, notably by a note by Scripture, Smith & Brown “On the education of muscular control and power“, published in Studies from the Yale Psychological Laboratory in 1894.  It describes how resistance training in an ipsilateral limb produces strength gains in the contralateral limb and indicates that strength training produces a central adaptation and not just a local one.

This cross-over effect was observed in strength training and static stretching. Static stretching of the ipsilateral limb produces acute increases in ROM in the contralateral limb, as well as other limbs across the upper and lower body. Static stretching of the ipsilateral limb can also affect force production in the contralateral limb.

And thus it was hypothesised that foam rolling may also produce a cross-over effect to contralateral limbs but this has not yet been confirmed.

Researchers from Birmingham and London in the UK recently explored the potential cross-over effect of foam rolling by investigating the effects of the rolling application on the ipsilateral limb of 3 bouts of 30 seconds. They then measured changes in ipsilateral and contralateral ankle dorsiflexion ROM and assessed the time-course of those effects up to 20 minutes post-treatment. The research used a within- and between-subject design, and was carried out in a convenience sample of 26 subjects, allocated into foam rolling (n=13) and control (n=13) groups. Ankle dorsiflexion ROM was recorded at baseline with the in-line weight-bearing lunge test for both ipsilateral and contralateral legs. Straight after ROM measurement, subjects in the treatment group carried out the foam rolling the calf musculature of the dominant leg (leg used to kick a ball) for three bouts of 30 seconds, with 10-second rest intervals between bouts, for a total time of two minutes. Subjects in the control group remained in a long sitting resting position for two minutes. Ankle dorsiflexion ROM was reassed at 0, 5, 10, 15, 20 minutes following treatment or control.

The results showed no significant between-group effect was seen following the intervention. However, a significant within-group effect in the Foam Rolling group was seen between baseline and all post-treatment time-points (0, 5, 10, 15 and 20 minutes). Significant within-group effects were also seen in the ipsilateral leg between baseline and at all post-treatment time-points, and in the contralateral leg up to 10 minutes post-treatment, indicating the presence of a cross-over effect.

The researchers concluded that Foam Rolling improves ankle dorsi flexion ROM for at least 20 minutes in the ipsilateral limb and up to 10 minutes in the contralateral limb, indicating that foam rolling produces a cross-over effect into the contralateral limb. The mechanism producing these cross-over effects is unclear but may involve increased stretch tolerance, as observed following a static stretch.

Although the absolute increase in ankle dorsiflexion ROM was small and may not be clinically meaningful for healthy populations, the cross-over effect has potential applications where ROM is restricted on one side of the body as a result of injury, post-operation immobilization or neurological conditions. In such cases, foam rolling on the healthy limb may have benefits through the cross-over effect into the injured limb.

This study was published in Int J Sports Phys Ther