Analysis of Heel Raise Exercise with Three Foot Positions

Prior research revealed activation differences between the medial (MG) and lateral (LG) gastrocnemius when performing heel raise exercise with neutral (N), internally-rotated (IR) and externally-rotated (ER) foot positions. Studying underlying biomechanics may help explain activation differences. The purpose was to compare ankle (AN), knee (KN), and hip (HI) contributions (initial joint angles) to attaining each initial foot position, ankle flexion-extension range of motion, ankle mechanical energy expenditure, repetition time, and percent cycle concentric-eccentric transition between N, IR, and ER foot positions. Twenty healthy subjects (11 male, 9 female) with resistance training experience performed twelve repetitions of free-weight (135% body mass) heel raise exercise using N, IR and ER foot positions in a counterbalanced order. Forefeet were elevated .05m onto separate forceplates. Electromagnetic sensors secured along dominant lower limb recorded kinematic data. Dependent variables were averaged across five selected repetitions. No significant differences existed for repetition time (P=.209), percent cycle concentric-eccentric transition (P=.668), ankle mechanical energy expenditure (P=.590), and ankle flexion-extension range of motion (P=.129) between foot positions. Post hoc comparison of a significant joint by foot position interaction (P\u3c.001) demonstrated IR\u3eN\u3eER for the initial HI and KN angles, whereas for AN, ER\u3eIR and N. Between joints: ANA

Kinematic Analysis of Heel Raise Exercise With Three Foot Positions

Prior research revealed activation differences between the medial (MG) and lateral (LG) gastrocnemius when performing heel raise exercise with three different foot positions, neutral (N), internally-rotated (IR) and externally-rotated (ER). Studying underlying kinematics and kinetics may help provide explain the activation differences. PURPOSE: To compare ankle (AN), knee (KN), and hip (HI) contributions to achieving the start positions, ankle flexion-extension (FL-EX) range of motion (ROM), repetition time (RT), % cycle concentric-eccentric transition (%CT) and ankle extension mechanical energy expenditure (MEE) between N, IR and ER heel raise exercise. METHODS: Twenty healthy subjects (11 male, 9 female; 22.7±3.13yrs) with resistance training experience performed 12 repetitions of free-weight (135% body mass) heel raise exercise using N, IR and ER foot positions in a counterbalanced order. Repetitions began with forefeet elevated.05m onto separate forceplates. Electromagnetic sensors (Motion Monitor, IST, Inc) secured onto dominant foot, shank and thigh recorded kinematic data. Dependent variables were averaged across five selected repetitions. Temporal events (initiation, transition, end) were defined by AN FL-EX angular velocity. At repetition initiation, AN adduction/abduction (adduction positive), KN and HI rotation (IR positive) were determined. AN extension MEE was calculated as the absolute sum of the angular concentric and eccentric work. RESULTS: No significant differences existed for RT (P=.209), %CT (P=.668), MEE (P=.590), and AN FL-EX ROM (P=.129) between foot positions. Post hoc comparison of a significant start position angle joint by foot position interaction (P\u3c.001) demonstrated IR\u3eN\u3eER for HI and KN angles, whereas for AN, ER\u3eIR and N. Comparing between joints, AN CONCLUSION: Peak FL-EX ROM, MEE, RT, %CT are not affected by altering foot position during heel raise exercise. Although it was expected the IR/ER/N positions would induce large start AN angle changes, our results reveal the greatest changes at the HI, followed by the KN. The relatively small AN differences may be explained by beginning in a dorsiflexed position (closed pack). Further research is needed to explain the MG and LG activation differences previously reported

Kinematic Analysis of Heel Raise Exercise With Three Foot Positions

Presentation given at the Annual Meeting of the American College of Sports Medicine

Comparison of Standing Single Arm Shot Put Performance Between Limbs With Different Loads in Collegiate Baseball Players

Work published in Journal of Athletic Training

Effects of Medicine Ball Load on Chest Pass Performance and Selected Underlying Kinematics

Presentation given at the Annual Meeting of the American College of Sports Medicine

Comparison of Standing Single Arm Shot Put Performance Between Limbs With Different Loads in Collegiate Baseball Players

Presentation given at the National Athletic Trainers Association Annual Meeting

Effects of Medicine Ball Load on Chest Pass Performance and Selected Underlying Kinematics

The medicine ball (MB) chest pass (CP) is an upper extremity functional performance test commonly used, however the ideal MB load to use remains unknown. PURPOSE: To determine the effect of MB load on CP performance and to examine the relationship between CP performance and selected underlying kinematics. METHODS: Twenty-seven healthy collegiate-level baseball players (20.5±1.5yrs; 181.5±6.2cm; 84.7±8.7kg) performed three CP trials using 2kg, 3kg, and 4kg MB loads Instructions were given to hold MB at shoulder level with feet shoulder width apart and knees straight, and to press the MB for maximal distance without countermovement. Initial impact sites of each trial determined horizontal range (HR). Dominant hand and thorax kinematics (Motion Monitor, IST, Inc) were captured while a synchronized hand trigger indicated ball release (BR). Release height (RH), was defined as the vertical hand position at ball release. Additionally, anterior displacement (AD), vertical displacement (VD), anterior peak velocity (APV) and vertical peak velocity (VPV) of the hand relative to thorax were computed. All measures were averaged across the three trials. RESULTS: As expected, MB load had a potent significant effect on HR (P\u3c.001), however the difference between the 2kg and 3kg was the same as 3kg and 4kg (P=.176). Similarly, MB load had a significant effect (P=.023) on RH, with RH being significantly higher for the 3kg (P=.031) and 4kg (P=.030) compared to 2kg. Overall, AD was significantly greater than VD (P=.003) with load having no effect on either measure. For peak velocity, a significant load by direction interaction was revealed (P=.020). At each load, APV was significantly greater than VPV (P\u3c.001). For APV, 2kg was significantly greater than 3kg (P=.001) and 4kg (P\u3c.001), whereas for VPV 2kg was only significantly greater than 4kg (P=.004). Only RH demonstrated a significant relationship with HR (2kg: r=.62, P=.001; 3kg: r=.44, P=.021; 4kg: r=.530, P=.004). CONCLUSION: The 2kg appears to be the optimal load to use because it was associated with the highest peak velocities and a slightly lower RH. These suggest it is associated with greater power and being a more efficient and direct movement. Because only RH correlated with HR, further research is needed to understand the underlying factors contributing to MB CP performance

Medial and Lateral Gastrocnemius Activation Differences During Heel-Raise Exercise with Three Different Foot Positions

Riemann, BL, Limbaugh, GK, Eitner, JD, and LeFavi, RG. Medial and lateral gastrocnemius activation differences during heel-raise exercise with three different foot positions. J Strength Cond Res 25(3): 634-639, 2011-Despite little objective support, heel-raise exercises are commonly performed using varying foot positions in an attempt to alter medial (MG) and lateral (LG) gastrocnemius involvement. This investigation compared MG and LG activation during the concentric phase (CP) and eccentric phase (EP) of the heel-raise exercise using neutral (NE), internally rotated (IR), and externally rotated (ER) foot positions. Twenty healthy subjects (10 men, 10 women; age = 23.7 ± 3.1 years) with resistance training experience performed free-weight (130-135% body mass) heel-raise exercise on a 3.81-cm block. Surface electromyography activity was recorded during 10 repetitions of each foot position. Electromyography activity from 5 successful repetitions was normalized to maximum voluntary isometric contraction, ensemble averaged within phase (CP, EP), and the mean amplitude determined. Significant (p \u3c 0.05) muscle-by-foot position interactions were revealed for both phases. The ER position prompted significantly greater MG activation than LG during both phases, whereas the IR position elicited significantly greater LG activation than MG. These data support the notion that altering foot position during heel-raise exercise will prompt varying degrees of MG and LG activation. Although this study cannot predict whether muscle-activation differences between foot positions will translate into greater training adaptations, it does provide some initial objective evidence upon which practitioners can base the selection of gastrocnemius exercises

Medial And Lateral Gastrocnemius Activation Differences During Heel Raise Exercise With Three Different Foot Positions

Instructional guidelines from some national exercise certification organizations recommend performing heel raise exercise with varying initial foot positions to alter the involvement of the gastrocnemius\u27 medial (MG) or lateral (LG) head. PURPOSE: To compare MG and LG activation during the concentric (CP) and eccentric (EP) phases of heel raise exercise using neutral (N), internally-rotated (IR) and externally-rotated (ER) foot positions. The term foot position was maintained for consistency with instructional texts, though the initial foot position reflects hip rotation. METHODS: Twelve healthy subjects (9 male, 3 female; 24.0 ± 3.8yrs) with resistance training experience performed free-weight (bar loaded to 30% body mass) heel raise exercise on a 3.8 cm block. Surface electromyographic (EMG) activity was recorded during five repetitions under each of the N, IR and ER foot positions, divided into CP and EP phases, and ensemble averaged within phase. Mean EMG amplitude, normalized to maximum voluntary contraction, was calculated. Separate two-factor (position by head) repeated measures analysis of variance were used for each phase. Simple main effects post hoc analyses of the significant (P \u3c.05) interactions were conducted. RESULTS: During EP, significantly greater MG activity compared to LG activity was revealed for both N and ER. During CP, significantly greater LG activity compared to the MG occurred for IR. Further, post hoc analyses on the EP revealed that MG activity using ER was significantly greater than MG activity using IR or N. Likewise, analysis of CP revealed that LG activity using IR was significantly greater than LG activity using ER or N. CONCLUSION: Altering foot positions during the heel raise exercise does alter relative muscle activation as measured by surface EMG. The MG is activated to a significantly greater extent than the LG during EP using N and ER, while the LG displays significantly greater muscle activity than the MG during CP using IR. Further research is recommended to elucidate the role of the contraction phases in these differences

Comparison Of Spine Kinematics Between Dominant And Non-dominant Leg Kicking In Collegiate Women Soccer Players

Work published in Medicine & Science in Sports & Exercise