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  • Author: Marie A. Johanson x
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Marie A. Johanson, Brian J. Cuda, Jonathan E. Koontz, Julia C. Stell and Thomas A. Abelew

Context:

Stretching exercises are commonly prescribed for patients and healthy individuals with limited extensibility of the gastrocnemius muscle.

Objective:

To determine effects of gastrocnemius stretching on ankle dorsiflexion, knee extension, and gastrocnemius muscle activity during gait.

Design:

Randomized-control trial.

Setting:

Biomechanical laboratory.

Participants:

Sixteen volunteers (9 men and 7 women, mean age = 27 y) with less than 5° of passive ankle-dorsiflexion range of motion randomly assigned to an experimental or control group.

Intervention:

The experimental group performed gastrocnemius stretching for 3 wk.

Main Outcome Measures:

Maximum ankle dorsiflexion, maximum knee extension, and EMG amplitude of the gastrocnemius muscles were measured between heel strike and heel-off before and after intervention.

Results:

No significant effect of group or time was found on maximum ankle dorsiflexion, maximum knee extension, or EMG activity of the medial or lateral gastrocnemius muscles between heel strike and heel-off. The experimental group had significantly greater passive ankle-dorsiflexion range of motion bilaterally at posttest than the control group.

Conclusions:

Stretching did not alter joint angles or gastrocnemius muscle activity in the early to midstance phase of gait.

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Marie A. Johanson, Megan Armstrong, Chris Hopkins, Meghan L. Keen, Michael Robinson and Scott Stephenson

Context:

Stretching exercises are commonly prescribed for patients and healthy individuals with limited extensibility of the gastrocnemius muscle.

Objective:

To determine if individuals demonstrate more dorsiflexion at the ankle/rear foot and less at the midfoot after a gastrocnemius-stretching program with the subtalar joint (STJ) positioned in supination compared with pronation.

Design:

Randomized controlled trial.

Setting:

Biomechanical laboratory.

Participants:

22 volunteers with current or recent history of lower-extremity cumulative trauma and gastrocnemius tightness (10 women and 4 men, mean age 28 y) randomly assigned to stretching groups with the STJ positioned in either pronation (n = 11) or supination (n = 11).

Intervention:

3-wk home gastrocnemius-stretching program using a template to place the subtalar joint in either a pronated or a supinated position.

Main Outcome Measures:

A 7-camera Vicon motion-analysis system measured ankle/rear-foot dorsiflexion and midfoot dorsiflexion of all participants during stretching with the STJ positioned in both pronation and supination before and after the 3-wk gastrocnemius-stretching program.

Results:

A 2-way mixed-model ANOVA revealed a significant interaction (P = .019). At posttest, the group who performed the 3-week stretching program with the STJ positioned in pronation demonstrated more increased ankle/rear-foot dorsiflexion when measured with the STJ in pronation than the group who performed the 3-wk stretching program with the STJ positioned in supination. No significant main effect of stretching group or interaction for dorsiflexion at the midfoot was detected (P = .755 and P = .820, respectively).

Conclusion:

After a 3-wk gastrocnemius-stretching program, when measuring dorsiflexion with the STJ positioned in supination, the participants who completed a 3-wk gastrocnemius stretching program with the STJ positioned in pronation showed more increased dorsiflexion at the ankle/rear foot than participants who completed the stretching program with the STJ positioned in supination.